Bridge, MFT, achromats, dSLR, primes - a journey of exploration

[GardenersHelper]

Continued from previous post

It seems the Canon 70D and Sigma 105 Macro will let me capture the best looking (to my eye), most detailed images of my four rigs. So, what's the problem?

Reach. Flexibility, Ease, speed and creativity in use. And these latest tests suggest that these are non-trivial issues.

The Sigma 105 has, obviously, a fixed focal length of 105mm. You would think that this wouldn't matter with flowers etc. They are not going anywhere, so you have plenty of time, and you can “zoom with your feet”. Just move towards or away from the subject to alter the magnification/framing of the scene.

Except that sometimes, you can't. In a short session with a very small number of subjects I encountered two examples.

In one case there was a pond in the way; I simply couldn't get close enough with the Sigma 105 to get the framing I wanted. There is an obvious way around this - capture the image with the Sigma 105 and then crop. You can certainly do this, but you lose the benefits of the Sigma 105's better potential image quality.

This graphic shows the crops that need to be made to a Sigma 105 image to give it the same framing/magnification as using my zoom rigs at maximum magnification from the same place (on the tripod as near as I could get it to the edge of the pond).


0649 15 Equivalence crops by gardenersassistant, on Flickr

In the images for this exercise over at Flickr there are pairs of images, one of the pair being an image captured with one of the zoom rigs and the other of the pair being the Sigma 105 image cropped to give the same coverage.

The 70D and G3 images were captured at ISO 1600, and the FZ200 image at ISO 200, which is the ISO needed to get a similar shutter speed with the FZ200 as you need with the 70D or G3 when using an aperture that give similar dof. ISO 1600 was giving shutter speeds of around 1/60 sec with f/9 on the 70D. Given the breeze, ISO 1600 was not excessive. I find ISO 1600 gives acceptable results for botanical subjects as long as I don't crop much. However, the cropping needed to match the zoom rigs is non-trivial, and as you can see from the pairs of examples at Flickr, noise is a significant issue with the Sigma 105 crops.

Also, the more you crop, the more detail you lose, and such cropping to increase “reach” undercuts and in some cases (like this one in fact) may well completely negate or even reverse the advantages of the Sigma 105 in the amount of detail captured.

In the second example I would only have been able to get the framing I wanted with the Sigma 105 by putting the tripod on the flower bed, right where there was a patch of very delicate moss that takes years to develop; that was a non-runner. If I was limited to using the Sigma 105 this would have prevented me capturing various potentially quite nice images of a number of buds and flowers. As with the first example, I could have captured those shots with any of my other rigs with their zoom lenses. In both these examples I successfully used the 55-250 on the 70D. That won't always be possible, because even with the extra focal length I might not get close enough, but I do quite often use long focal lengths for flowers etc so the Sigma's shorter focal length could be a significant limitation at times.

The following graphic illustrates the range that I can cover without moving the camera with the 55-250 on the 70D (the differences in “working distance” are caused by the camera lens extending, not by the camera moving). The G3 +45-175 and the FZ200 (when set up the way I use it with an adaptor tube) provide similar, slightly smaller ranges. (3.9x for the G3 with the 45-175 and 3.4x for the FZ200 compared to 4.5x for the 70D with 55-250.)

On the left you see the focal lengths for the 55-250 which produced the images. On the right you see the working distances that would be needed with the Sigma 105 to capture the same images. With the Sigma 105, the camera would need to move just over a metre to move between the minimum and maximum magnifications/scene sizes the 55-250 can capture without moving.


0649 14 Reach ratio for 55-250 and working distances for 105 macro by gardenersassistant, on Flickr

Even if there is nothing stopping you placing the camera where it needs to be, it can still be very awkward. The flower I was photographing for the tests discussed in the previous post was somewhat inside the bush's foliage and the shots had to be aligned from somewhat above the flower. A tripod was essential because the low light levels were giving me exposures as slow as ½ second. I quickly discovered that in these circumstances, when trying to get a particular framing for the shot using the Sigma 105, you not only have to adjust the horizontal distance of the camera from the subject (which often involves moving the tripod despite using a focus rail), but you also have to adjust its height so as to maintain the “angle of attack”. This is slow, fiddly and surprisingly difficult to get right, very much so compared to using a zoom lens, with which you can change the framing in under a second without moving the camera or altering the angle of attack. And slowness can matter, because although the flowers aren't going anywhere, the light can change rather quickly, for example when a subject is illuminated by a stream of light coming through a gap in the foliage above, and the illumination can change quickly as the sun moves around, or changes in cloud cover, which can produce very rapid changes in illumination.

It gets worse, for me at least. I “compose by exploration”. That is, I don't see a shot by looking at the scene and then aligning the camera to capture what I see in my mind's eye. I explore the scene with the camera, ranging in and out as I adjust the angle of attack using the sideways focus rail and the adjustable arm. With the Sigma 105 I can use the sideways focus rail and the adjustable arm to alter the alignment, but I can't use the (back to front) focus rail or the adjustable arm to alter the distance to the subject enough to change the framing/magnification significantly. That needs the tripod to be moved, including any needed height adjustment. And that turns a smooth, continuous, rapid flow of creative compositional exploration into a complicated, disjointed, slow and frustrating procedure that quickly dries out the creative juices.

So where does all this lead?

Irrespective of whether I use the Sigma 105 or the 55-250, I think the 70D is probably the best of my cameras for botanical work. These tests have reinforced my view of how much better it is with manual focus than the G3 or FZ200, and my view that manual focus is my preferred mode for botanical work. In terms of image quality, it seems to me that irrespective of which lens I use, the 70D produces colours and textures that I find more natural looking and pleasing than the other cameras, and that the 70D raw files are easier and quicker to handle than those from the G3 and FZ200.

So if 70D is the camera to use, what about the lens? The 55-250 is much better in terms of capture workflow. So does the Sigma 150 have advantages that outweigh this?

• The Sigma 105 goes to f/2.8 rather than f/4-5.6 depending on focal length, and so has much greater potential for narrower dof shots. But I very rarely use f/2.8, or in fact anything less than f/5.6, and am usually disappointed with the results when I do, despite how good it might look to me on the LCD at capture time. On the other hand, rather than the f/22 limit of the Sigma 105, the 55-250 goes to f/22-32 depending on focal length, and I have used those smaller apertures successfully for botanical shots.
• The Sigma 105 captures more detail in the in-focus areas than the 55-250. However, I have had to pixel peep to be sure about that. I rarely crop my botanical shots much – I tend to compose to the edge of the frame. This means that, given my output sizes (1100 pixels high on screen and A4 and only occasionally larger in print) most of the extra detail is not going to be visible to the viewer of the finished result. Much of the extra in-focus detail therefore seems to be, for my purposes, irrelevant.
• The Sigma 105 captures more detail/provides better microcontrast or some such in the less in focus and out of focus areas, and I suspect gives better overall clarity and “presence” to at least some images. I think these are probably its main attractions to me at this stage.

And now?

I'm not convinced about some of these tentative conclusions (e.g. overall image clarity/”presence”), and I don't yet have a good feel for how relevant any image detail issues are for my type of outputs. I think I need to spend more time using both lenses, seeing if I can learn to handle the Sigma 105 more fluidly, from time to time doing some more comparisons between the Sigma 105 and the 55-250 (bearing in mind that too much of that sort of thing is a great de-motivator), and spending more time processing images captured with the two lenses to get a better feel for their characteristics and potential.

It's looking to me that, despite the dust bunny problems I have encountered, I'm going to have to take both the Sigma 105 and the 55-250 out with me and get used to changing lenses in the field. Based on earlier work I will be taking the G3 for small aperture and medium/high magnification invertebrate captures (i.e. most of my invertebrate captures).

It is still in open question as to what I might best use for natural light shots of

• larger invertebrates such as butterflies and dragonflies,
• snails and slugs in motion
• medium to large size flies and similar sized subjects

 

[LCPete]

Interesting as always Nick especially that you are finding the 55-250 to be very good for flower pictures
I don't tend to experiment with equipment much so always find your posts interesting
when I do carry two lenses I normally have each one on a camera body to save messing around changing lenses
my spare body is a canon 550D its a bit well used and battered now but has really nice image quality and they can be picked up cheaply now
I normally only carry one camera and lens tho as I like to travel light and keep things simple but I have missed out a few times by not having enough reach for insects in awkward spots

 

[LCPete]

Just to add I have mentioned this before but you will definitely love the sigma 105 when the larger insects are out, butterflies and damselflies etc as the detail/quality that you get with insects with that lens is wonderful
although it's a bit harder to approach some butterflies with the shorter macro lens than it is with a longer zoom lens when you get the shot its worth it

 

[GardenersHelper]

Interesting as always Nick especially that you are finding the 55-250 to be very good for flower pictures
I don't tend to experiment with equipment much so always find your posts interesting

Thanks Pete. I've been doing some more comparisons in the past couple of days. I'm realising more and more just how much better the 55-250 fits with my way of working. However, I haven't cracked the image quality issue yet. It is proving surprisingly difficult to produce meaningful real world comparisons, even when I'm being really careful, mainly I think because of the very small amount of suitable subject matter (in places where I can get at it) coupled with low light levels and breeze, which make it difficult to get any half-decent results and even more difficult to get consistent results. The results so far have been too inconsistent to draw conclusions from, but I'm seeing hints that I'm going to prefer images from the 105 when I do get some comparisons that work properly.

when I do carry two lenses I normally have each one on a camera body to save messing around changing lenses
my spare body is a canon 550D its a bit well used and battered now but has really nice image quality and they can be picked up cheaply now
I normally only carry one camera and lens tho as I like to travel light and keep things simple but I have missed out a few times by not having enough reach for insects in awkward spots

That makes sense. I'll be carrying (at least) two cameras with me. It's conceivable that (as well as the achromats, tripod and other bits and pieces) I'll end up carrying three cameras (70D, G3 and FZ200), two lenses for the 70D (55-250 and 105) and two flash units (one for the 70D, one for the G3 and FZ200). I hope it won't come to that though.

Just to add I have mentioned this before but you will definitely love the sigma 105 when the larger insects are out, butterflies and damselflies etc as the detail/quality that you get with insects with that lens is wonderful
although it's a bit harder to approach some butterflies with the shorter macro lens than it is with a longer zoom lens when you get the shot its worth it

Yes, I'm looking forward to trying that. Unfortunately I don't see many larger insects, so I hope that when I do I have the 105 with me and have time to change to it if necessary.

 

[LCPete]

[QUOTE="GardenersHelper, post: 6652968, member: Unfortunately I don't see many larger insects, so I hope that when I do I have the 105 with me and have time to change to it if necessary.[/QUOTE]

it can be tricky to find many dragonflies especially ones that are perched I struggle myself to find many especially hawkers
damselflies though aren't to hard to find and it's well worth searching out sheltered areas near to the water as they make great subjects, in fact they're my favourites but can be frustrating often flying off just when you get lined up!
I try to get out to the site as early as I can before they get warmed up

 

[LCPete]

. I'll be carrying (at least) two cameras with me. It's conceivable that (as well as the achromats, tripod and other bits and pieces) I'll end up carrying three cameras (70D, G3 and FZ200), two lenses for the 70D (55-250 and 105) and two flash units (one for the 70D, one for the G3 and FZ200). I hope it won't come to that though.


.

That's a lot of gear
I've been carrying just the camera and lens and a few bits in pockets , have been trying to manage without a bag
I don't normally even carry a flashgun, I found that when I took more gear I didn't feel like walking far to find the best spots
but I do see why you do as you're going for a wider range of subjects

 

[GardenersHelper]

it can be tricky to find many dragonflies especially ones that are perched I struggle myself to find many especially hawkers
damselflies though aren't to hard to find and it's well worth searching out sheltered areas near to the water as they make great subjects, in fact they're my favourites but can be frustrating often flying off just when you get lined up!
I try to get out to the site as early as I can before they get warmed up

Yes, I see more damselflies than dragonflies. Like you say, it's easier before they warm up. I have found damselflies early in the morning, soon after dawn when they can be prettily covered in dew drops, as well as later in the day. But I don't recall ever finding a dragonfly other than in rather bright, middle of the day sunny conditions, and even that has been pretty rare for me.

My sessions at the nature reserves tend to be from dawn to midday at the latest and late afternoon in our garden. I don't think I've ever photographed a dragonfly in our garden. A couple of the nature reserves are well known for dragonflies, but I hardly ever come across them. Perhaps I'm out there at the wrong time of day for dragonflies.

That's a lot of gear
I've been carrying just the camera and lens and a few bits in pockets , have been trying to manage without a bag
I don't normally even carry a flashgun, I found that when I took more gear I didn't feel like walking far to find the best spots
but I do see why you do as you're going for a wider range of subjects

Have to admit I rarely walk very far, usually no more than a couple hundred metres or so from the car, often much less depending on the site. I then put the kit down and that becomes my "base camp", and then it's usually a few steps at a time interspersed with a lot of crawling around on my knees.

 

[GardenersHelper]

As part of my response to Pete's @LCPete thread is it possible to use extension tubes without flash I have been trying to do a comparison of the Marumi 200 and Raynox 150 achromats. I've run into difficulties in getting consistent results, and I have come across one strange thing which may explain some of my difficulties. It has to do with working distances and focusing.

Today I have been using these achromats on the 18-55 STM on my 70D. This first graphic shows three 100% crops taken from test images with the Marumi 200 on the 18-55 STM at 18mm focal length . (I don't think this is a problem with the Marumi by the way - I think it is a problem with the 70D and/or 18-55, and possibly it applies to other of my lenses and cameras as well. I'm going to have to test all that. )


0659 04 2015_01_13 AF and MF 100pc comparison crops by gardenersassistant, on Flickr

I was trying to find out what the maximum working distance was for the 18-55 with the Marumi on it. (All these test images were captured with the camera on a tripod with a focus rail, using flash, having magnified the view to 10x on the LCD, which for autofocus makes the camera focus on a very small area of the image, and having waited for the 10x image to come completely to rest before capturing the image using a remote release.)

I increased the distance from the subject until I could no longer gain autofocus confirmation. I then reduced the distance a fraction so I could get autofocus confirmation and captured the first image, at 29.5cm working distance. I then switched the camera to manual focus and, using 10x magnification in live view, I tried to get a sharp image. I couldn't. The second crop shows the best that I could get, which is rather similar to the autofocus result. I then decreased the working distance until I could get a sharp-looking 10x result on the LCD; this needed a reduction in working distance of 4.5cm to 25cm. The third image is a crop from that image, which is significantly sharper than the images captured at 29.5cm.

So, it turns out that you can get autofocus confirmation even though the image isn't properly sharp.

It gets worse.

This graphic relates to the Marumi on the 18-55 again, but this time at 55mm focal length. In this case the maximum working distance for a sharp manually focused image was 21.5cm. However, I could get autofocus confirmation as far out as 28cm working distance, at which point the image was really out of focus.


0659 17 2015_01_13 AF beyond, at and nearer than max sharp working distance100pc crops by gardenersassistant, on Flickr

I expect you'll need to click through to Flickr to see this graphic large enough to make sense of it, but here are the first and second crops from it.

Here is the crop from the manual focus at 21.5cm working distance.


0659 05 2015_01_13 Marumi 200 on 18-55 at 55mm on Canon 70D MF Max WD 215mm to get sharp at 10x live view by gardenersassistant, on Flickr

And here is the crop from a capture with autofocus confirmed at 28cm.


0659 06 2015_01_13 Marumi 200 on 18-55 at 55mm on Canon 70D AF after hunting WD 280mm LCD AF not looking s by gardenersassistant, on Flickr

Now, there were several seconds of hunting before I got autofocus confirmation, but even so I'm astonished I got confirmation at all for that degree of out of focus. Out in the field I sometimes depend (or at least, before today I used to depend!) on the sound of the focus confirmation without taking any notice of what is on the LCD.

It turns out that for these very much out of focus captures the image on the LCD after autofocus confirmation is obtained is not very sharp, although that is less the case as the working distance approaches the critical value. At 22cm for example, as shown in the graphic, the image is not as sharp as it is at 21.5cm or lesser distances, but I don't think it would be possible to tell that from looking at the LCD out in the field. And some of the worse results might not be easy to spot either, especially if the ambient light is bright/at the wrong angle, making the LCD difficult to see properly.

I need to do some more tests to see how widespread this issue is.

 

[LCPete]

[QUOTE="GardenersHelper, post: 666749member:]As part of my response to Pete's @LCPete thread is it possible to use extension tubes without flash I have been trying to do a comparison of the Marumi 200 and Raynox 150 achromats. I've run into difficulties in getting consistent results, and I have come across one strange thing which may explain some of my difficulties. It has to do with working distances and focusing.

Today I have been using these achromats on the 18-55 STM on my 70D. This first graphic shows three 100% crops taken from test images with the Marumi 200 on the 18-55 STM at 18mm focal length . (I don't think this is a problem with the Marumi by the way - I think it is a problem with the 70D and/or 18-55, and possibly it applies to other of my lenses and cameras as well. I'm going to have to test all that. )


0659 04 2015_01_13 AF and MF 100pc comparison crops by gardenersassistant, on Flickr

I was trying to find out what the maximum working distance was for the 18-55 with the Marumi on it. (All these test images were captured with the camera on a tripod with a focus rail, using flash, having magnified the view to 10x on the LCD, which for autofocus makes the camera focus on a very small area of the image, and having waited for the 10x image to come completely to rest before capturing the image using a remote release.)

I increased the distance from the subject until I could no longer gain autofocus confirmation. I then reduced the distance a fraction so I could get autofocus confirmation and captured the first image, at 29.5cm working distance. I then switched the camera to manual focus and, using 10x magnification in live view, I tried to get a sharp image. I couldn't. The second crop shows the best that I could get, which is rather similar to the autofocus result. I then decreased the working distance until I could get a sharp-looking 10x result on the LCD; this needed a reduction in working distance of 4.5cm to 25cm. The third image is a crop from that image, which is significantly sharper than the images captured at 29.5cm.

So, it turns out that you can get autofocus confirmation even though the image isn't properly sharp.

It gets worse.

This graphic relates to the Marumi on the 18-55 again, but this time at 55mm focal length. In this case the maximum working distance for a sharp manually focused image was 21.5cm. However, I could get autofocus confirmation as far out as 28cm working distance, at which point the image was really out of focus.


0659 17 2015_01_13 AF beyond, at and nearer than max sharp working distance100pc crops by gardenersassistant, on Flickr

I expect you'll need to click through to Flickr to see this graphic large enough to make sense of it, but here are the first and second crops from it.

Here is the crop from the manual focus at 21.5cm working distance.


0659 05 2015_01_13 Marumi 200 on 18-55 at 55mm on Canon 70D MF Max WD 215mm to get sharp at 10x live view by gardenersassistant, on Flickr

And here is the crop from a capture with autofocus confirmed at 28cm.


0659 06 2015_01_13 Marumi 200 on 18-55 at 55mm on Canon 70D AF after hunting WD 280mm LCD AF not looking s by gardenersassistant, on Flickr

Now, there were several seconds of hunting before I got autofocus confirmation, but even so I'm astonished I got confirmation at all for that degree of out of focus. Out in the field I sometimes depend (or at least, before today I used to depend!) on the sound of the focus confirmation without taking any notice of what is on the LCD.

It turns out that for these very much out of focus captures the image on the LCD after autofocus confirmation is obtained is not very sharp, although that is less the case as the working distance approaches the critical value. At 22cm for example, as shown in the graphic, the image is not as sharp as it is at 21.5cm or lesser distances, but I don't think it would be possible to tell that from looking at the LCD out in the field. And some of the worse results might not be easy to spot either, especially if the ambient light is bright/at the wrong angle, making the LCD difficult to see properly.

I need to do some more tests to see how widespread this issue is.[/QUOTE]


Hi Nick
it looks like the achromat is interfering with the auto focus which is a shame
it will change the way that I work same for you I guess
will have to zoom in on live view and focus manually i think
i wonder why the camera gives the focus conformation that is very odd
i cant see why the achromat in front of the lens would change anything but i dont really understand in detail how the autofocus works
from what i understand you are doing you were using the live veiw autofocus , have you tried the normal shutter button focus?

 

[GardenersHelper]

it looks like the achromat is interfering with the auto focus which is a shame
it will change the way that I work same for you I guess

I've done some more tests. I can get the same effects with the Raynox 150 on the 18-55 so the Marumi isn't the problem. I can get the same effects with the Raynox 150 on the 55-250, so the 18-55 isn't the problem.

I can't get the same effects with the Raynox 150 on either the G3 with 45-175 or the FZ200. They have very different autofocus behaviour. There is no hunting. There is a short delay before focus is achieved, but if focus isn't achieved in that short time there is no subsequent hunting. It is a very positive thing of either it finds focus or it doesn't. And I could get to the maximum working distance at which autofocus would confirm, then increase the distance by 1mm or so, and it would not confirm, move back by 1mm or so and it would confirm, and repeat. There is a very clear cut-off distance at which it simply won't lock on. Within that distance, you get pretty quick (i.e. non-hunted) confirmation and you get good focus.

I can't get the same effects with the Sigma 105. Since it has infinity focus I obviously couldn't get a maximum working distance fault, but I tried to get bad autofocus by finding the working distance to get a sharp image with manual focus at 1:1, and then moving the camera slightly closer and trying autofocus. It wouldn't work. As with the Panasonics+Raynox, it was a very positive, clear cut yes or no.

That seems to suggest it is an issue with the 70D and achromats. So you might not have the same problem as you aren't using a 70D.

will have to zoom in on live view and focus manually i think

Well, try it and see what you think. It may depend on how it is implemented on your camera. On my 70D I don't really like to zoom in for focusing as I lose compositional context, and I work quite tight to the edges of the screen, and even when I'm working tripod-assisted holding the composition needs continual awareness and microadjustments. Judging dof placement for flowers can also require a wider view than a 5x or 10x zoomed in area. Fortunately the LCD on the 70D is really good and I find it ok to judge manual focus and dof placement with the LCD unmagnified, including quite delicate dof placement for flowers, which I find is much more difficult than with invertebrates, because of the much more irregular topography of the subject with flowers. At least, I find it ok in not too bright conditions. I haven't really tried it in bright conditions.

i wonder why the camera gives the focus conformation that is very odd
i cant see why the achromat in front of the lens would change anything but i dont really understand in detail how the autofocus works
from what i understand you are doing you were using the live veiw autofocus , have you tried the normal shutter button focus?

Good question. I hadn't looked at this because as you know I don't use phase detect autofocus. However, it turns out that there is a similar problem. Phase detect won't give focus confirmation nearly as far out as live view autofocus will, but it will give focus confirmation further out than the working distance for getting a sharp image with live view manual focus, and you get a poorly focused image. The following graphic illustrates this.


0659 24 2015_01_14 Comparison AF vs PDF max working distance by gardenersassistant, on Flickr

Here is the Phase detect 100% crop at maximum working distance of 23cm.


0659 18 2015_01_14 Raynox 150 on 18-55 STM at 55mm on Canon 70D Phase Detect Max WD 23cm IMG_1027 LR 100pc by gardenersassistant, on Flickr

And here is the 100% crop at the distance of 22cm needed for a sharp image on the LCD using live view 10x magnification.


0659 19 2015_01_14 Raynox 150 on 18-55 STM at 55mm on Canon 70D Live View 10x mag Manual Focus Max WD 22cm for sharp image by gardenersassistant, on Flickr

 

[LCPete]

I've done some more tests. I can get the same effects with the Raynox 150 on the 18-55 so the Marumi isn't the problem. I can get the same effects with the Raynox 150 on the 55-250, so the 18-55 isn't the problem.

I can't get the same effects with the Raynox 150 on either the G3 with 45-175 or the FZ200. They have very different autofocus behaviour. There is no hunting. There is a short delay before focus is achieved, but if focus isn't achieved in that short time there is no subsequent hunting. It is a very positive thing of either it finds focus or it doesn't. And I could get to the maximum working distance at which autofocus would confirm, then increase the distance by 1mm or so, and it would not confirm, move back by 1mm or so and it would confirm, and repeat. There is a very clear cut-off distance at which it simply won't lock on. Within that distance, you get pretty quick (i.e. non-hunted) confirmation and you get good focus.

I can't get the same effects with the Sigma 105. Since it has infinity focus I obviously couldn't get a maximum working distance fault, but I tried to get bad autofocus by finding the working distance to get a sharp image with manual focus at 1:1, and then moving the camera slightly closer and trying autofocus. It wouldn't work. As with the Panasonics+Raynox, it was a very positive, clear cut yes or no.

That seems to suggest it is an issue with the 70D and achromats. So you might not have the same problem as you aren't using a 70D.



Well, try it and see what you think. It may depend on how it is implemented on your camera. On my 70D I don't really like to zoom in for focusing as I lose compositional context, and I work quite tight to the edges of the screen, and even when I'm working tripod-assisted holding the composition needs continual awareness and microadjustments. Judging dof placement for flowers can also require a wider view than a 5x or 10x zoomed in area. Fortunately the LCD on the 70D is really good and I find it ok to judge manual focus and dof placement with the LCD unmagnified, including quite delicate dof placement for flowers, which I find is much more difficult than with invertebrates, because of the much more irregular topography of the subject with flowers. At least, I find it ok in not too bright conditions. I haven't really tried it in bright conditions.



Good question. I hadn't looked at this because as you know I don't use phase detect autofocus. However, it turns out that there is a similar problem. Phase detect won't give focus confirmation nearly as far out as live view autofocus will, but it will give focus confirmation further out than the working distance for getting a sharp image with live view manual focus, and you get a poorly focused image. The following graphic illustrates this.


0659 24 2015_01_14 Comparison AF vs PDF max working distance by gardenersassistant, on Flickr

Here is the Phase detect 100% crop at maximum working distance of 23cm.


0659 18 2015_01_14 Raynox 150 on 18-55 STM at 55mm on Canon 70D Phase Detect Max WD 23cm IMG_1027 LR 100pc by gardenersassistant, on Flickr

And here is the 100% crop at the distance of 22cm needed for a sharp image on the LCD using live view 10x magnification.


0659 19 2015_01_14 Raynox 150 on 18-55 STM at 55mm on Canon 70D Live View 10x mag Manual Focus Max WD 22cm for sharp image by gardenersassistant, on Flickr

Thanks again Nick
The achromat does affect the shutter button focus as well as live view focus then thats a shame

I would guess that if the achromat affects focus on your 70D my 7D will be the same
i will try it out anyway though hopefully i will be able to find something in the garden to shoot
I don't use live view auto focus on my 7D its too slow to be much use but the system on the 70D is much better
most of the time for subjects in nature reserves I hand hold and use viewfinder and auto focus
if I'm able to use a tripod because the subject isn't going to fly off I use live view to frame the subject then zoom in on the screen and manually focus
It's looking like that's what I'll have to do with the Marumi achromat
not too much of a problem as because the working distance will be very close I will only be able to use the achromat for damselflies etc that are too cold or wet to fly

 

[GardenersHelper]

Note: there are 1100 pixel high versions of the images discussed in this post over at Flickr in this album.

I illustrated in a previous post how, when it has an achromat attached to it, the 70D can give focus confirmation in cases where the working distance is too large for good focus, resulting in an image of slightly suboptimal to absolutely terrible (lack of) sharpness. It seems that the same is the case if the working distance is too small.

This image was captured with the 70D using manual focus, with a Raynox 150 on the 55-250 STM at 55mm focal length, using the minimum working distance at which I could get a sharp image (20.5cm).


0659 26 2015_01_14 Raynox 150 on 55-250 at 55mm on Canon 70D MF at min WD of 20.5cm for sharp image on LCD LR 1100h by gardenersassistant, on Flickr

Here is an image of the same scene (btw, this is the whole image, not a crop), with the same setup, but using autofocus, at the minimum working distance (9.5cm) at which I could get focus confirmation (after hunting).


0659 25 2015_01_14 Raynox 150 on 55-250 at 55mm on Canon 70D AF confirmed at 9.5cm WD IMG_1036 LR 1100h by gardenersassistant, on Flickr

I previously said that my Panasonic cameras don't suffer from this problem. That is true in the sense that I can't get anything with them like the terrible results I can get with the 70D. However, when I did this same exercise with the Raynox 150 on the 45-175 I did get a significantly worse result with the autofocused shot. Here are 100% crops from the centre of the image, autofocused on top, manually focused below. I need to do more tests at both too short and too long working distances to work out how serious a problem this is.


0659 28b Comparison AF and MF 100pc crop by gardenersassistant, on Flickr

I have done several more (natural light) comparisons of the Marumi 200 and Raynox 150, using both autofocus and manual focus. I used the 45-175 on the G3. For autofocus I used the G3's "pinpoint" focus which allows very tight control over exactly where the focus is centred, and I centred the focus in the same place for each pair of Marumi/Raynox test runs. For manual focus I used the G3's magnified view, again looking at the same small area for each pair of test rusns. I also took great care to try to get the subject parallel to the plane of the sensor.

In these comparisons, the most careful I have yet done, the Marumi came out consistently worse, in every test run, using manual focus and autofocus, and at every aperture. Here is a 100% crop manual focus example at f/11 (which is the middle of the f/5.6 to f/22 range of the 45-175). These crops are from the centre of one of the pairs of images. Over at Flickr you can see 10 pairs of crops like this, and 1100 pixel high versions of the images from which they were taken. I think these show that the differences shown here are representative of the results for these particular test runs, and that the differences extended right out to the edges of the images. (These captures were focused by turning a wheel on the focus rail a fraction of a turn at a time to try to obtain the sharpest image on the LCD using a magnified view in live view.)


0659 67 2015_01_14 Comparison 100pc crops F11 manual focus Raynox 150 top Marumi 200 bottom by gardenersassistant, on Flickr

 

[LCPete]

The Marumi looks unusable in those comparisons Nick
I wonder why its so bad on the G3
Mine hasn't arrived yet but I will be very disappointed if it's like that on my 7D
it's looking like the Raynox will be the best option

 

[LCPete]

Hopefully the Marumi will give sharp results on a DSLR but it looks like at the moment the Ranox is a better bet
you're also showing that for achromats generally manual focus is the best option for consistent sharp results

 

[LCPete]

The Marumi 200 has just arrived will give it a test today on my Canon 100 macro and 7D

 

[GardenersHelper]

The Marumi looks unusable in those comparisons Nick
I wonder why its so bad on the G3

With those comparisons, I agree. But I'm astonished that the Marumi ones are so much worse. Perhaps I did something wrong, although I've been scratching my head about that and I can't think what it might be, as I was individually focusing shots using manual focus, with exactly the same technique for the Marumi and Raynox. I've improved the test arrangement a bit more. Perhaps I'll redo the tests and also do them with the 70D and FZ200 to find out if it is an issue with the G3 in particular. (The earlier FZ200 comparison I linked to did give somewhat similar results of course.)

Mine hasn't arrived yet but I will be very disappointed if it's like that on my 7D
it's looking like the Raynox will be the best option

That's how it is looking to me (unless I've messed up the testing of course), for my Raynox and my Marumi, but there can be sample variation. If these results are valid then perhaps I just have poor example of the Marumi. Remember the other things you have read about the Marumi being sharper, especially at the edges. You'll have your own Marumi soon, although of course you won't be able to do comparisons with the Raynox. You could do comparisons with the 100L perhaps, although that wouldn't tell you anything about whether a Raynox would be better for you. But it might give you a comparison to help you gauge what sort of image quality you can get with the Marumi.

 

[GardenersHelper]

you're also showing that for achromats generally manual focus is the best option for consistent sharp results

I've just done a rather careful test run this morning looking specifically at AF vs MF, and it turns out that, for that test run at least, autofocus was better. I'll explain in a post later.

 

[GardenersHelper]

The Marumi 200 has just arrived will give it a test today on my Canon 100 macro and 7D

I shall be very interested to see how you get on with it.

 

[GardenersHelper]

I previously said that my Panasonic cameras don't suffer from this problem. That is true in the sense that I can't get anything with them like the terrible results I can get with the 70D. However, when I did this same exercise with the Raynox 150 on the 45-175 I did get a significantly worse result with the autofocused shot. Here are 100% crops from the centre of the image, autofocused on top, manually focused below. I need to do more tests at both too short and too long working distances to work out how serious a problem this is.

I did another test run to compare autofocus and manual focus results from the short end through to the long end of the range in which I could get autofocus confirmation. I used the G3 with the Raynox 150 on the 45-175 at 175mm, at f/11.

The target coin was fixed securely to the outside of a roll of packing tape so that, with the roll of tape on the table the coin would be vertical, and would not move. As with all my recent tests, the tripod was on a solid floor. I used natural light and a wired remote release.

I first established the range of working distances over which I could get focus confirmation. This was, rather conveniently, from 15.5 cm to 20cm. As I was expecting any issues to be most evident towards the ends of the range, I captured 5 images at 1mm intervals at each end of the range, and at 5mm intervals in the rest of the range. (i.e. 15.5, 15.6, 15.7, 15.8, 15.9, 16, 16.5, 17, 17.5, 18, 18.5, 19, 19.5, 19.6, 19.7, 19.8, 19.9, 20cm)

I did one series capturing images at these distances using the G3's pinpoint autofocus, and another series at the same distances using manual focus (using the focus ring) with a magnified view. I focused on the same area of the target in both cases. This gave me 18 pairs of images to compare. 1100 pixel high versions of the images are in this album at Flickr, along with 100% crops of the area on which I was focusing.

When I compared the 1100 pixel pairs I scored them as AF better in 10 cases, MF better in 2 cases and 6 cases of "so similar I can't say which is better" (different parts of the image can be in better focus as between the images in a pair). I then compared the 100% crops, which concentrated my eyes on exactly that area on which I wanted the best focus to fall, which is what matters most to me out in the field, where I'm trying to place the centre of dof exactly where I want it. In this case I scored them as AF better in 13 cases, MF better in 4 cases, and 1 case of a tie. The differences were very small in some cases, but to my eye AF seemed significantly better in half a dozen or so cases.

I also had a look through the autofocus images to see how much the focus deteriorated at either end of the range. Much to my surprise I didn't see any systemic deterioration at either end. Nor did I with the manual focus images. There was no pattern to the variations in focus that I could discern, other than to notice that the cases in which I thought the manual focus result was better were towards the short end of the range, three of the four I think falling in the first 0.5cm of the range.

I was interested, and somewhat relieved, to note that the focus ring was set at just less than closest focus for a sharp manually focused image at the short end of the working distance range which had been determined using autofocus confirmation. Similarly, at the long end of the working distance range the focus ring was set at just less than the furthest focus to get a sharp image. This indicates that, unlike with the 70D, autofocus on the G3 won't take you outside of the good working distance range.

I will continue to use autofocus with the G3. It appears to be at least as accurate as manual focus, across the whole focusing range. I find it quick and convenient to use. When working with achromats it is important to be in the appropriate working distance range, and autofocus confirmation provides feedback that you are in the appropriate range (at least, it does with the G3, but not with the 70D, see previous posts). In contrast, when using manual focus you don't have any such feedback and so you may get the sharpest image you can, for example using rocking focus, but the image may not be optimally sharp because the camera is outside of the working distance range in which optimal focusing is possible.

Another issue this test made very clear to me is how fiddly manual focus is compared to autofocus when using this particular tripod technique. This is because the act of moving the focus ring (as with the alternative of adjusting the focus rail) joggles the image around, making it difficult to tell when best focus has been achieved. Also, as the the camera "settles" when you stop the adjustments it, and hence focus point, may move. In contrast, autofocus can be done hands-off (via a remote release) and even if done hands-on you can use a "straight-through" technique of pressing the shutter button all the way down without pausing for focus confirmation, which means the time between focus being registered and the shot being taken (and hence the time for the camera to move) is very short indeed.

 

[LCPete]

will be very interested to see how you get on with it.

Hi Nick am struggling at the moment can't get sharp enough results with the marumi
I am taking shots of a coin with 7D with canon 100 mm macro fitted with either extension tubes or Marumi 200
i can get sharp results with tubes but not with the marumi
it may be my technique will try again tomorrow
am not getting much light which isnt helping

 

[GardenersHelper]

Hi Nick am struggling at the moment can't get sharp enough results with the marumi
I am taking shots of a coin with 7D with canon 100 mm macro fitted with either extension tubes or Marumi 200
i can get sharp results with tubes but not with the marumi
it may be my technique will try again tomorrow
am not getting much light which isnt helping

What distance are you working at? With the 100L set to focus at infinity, and with the Marumi on it, it should come into focus at about 20cm (The focal length of a close-up lens is 1metre / diopters, which is 1/5 metre for the 5 diopter Marumi, i.e. 20cm).

I've just checked this with the Marumi 200 on the Sigma 105. With the 105 set to infinity focus, using manual focus with magnified live view it focused at 203mm. I'll post what I got later. SWMBO requires some vegetables to be peeled. Immediately.

 

[LCPete]

What distance are you working at? With the 100L set to focus at infinity, and with the Marumi on it, it should come into focus at about 20cm (The focal length of a close-up lens is 1metre / diopters, which is 1/5 metre for the 5 diopter Marumi, i.e. 20cm).

I've just checked this with the Marumi 200 on the Sigma 105. With the 105 set to infinity focus, using manual focus with magnified live view it focused at 203mm. I'll post what I got later. SWMBO requires some vegetables to be peeled. Immediately.

I'm at the minimum focus distance of the marumi about six iinches
I will have another try tommorrow it may just be that im not getting a high enough shutter speed and getting movement

 

[LCPete]

I'm not used to working at high magnification which doesn't help but I do suspect that the marumi achromat isn't as sharp as using the tubes but want to be sure before I send it back
I don't want to it would be great if it it does work out its a quick and easy way to get more mag just screw it to the front of the lens
I will have another go tomorrow with a battery as a test

 

[GardenersHelper]

I'm at the minimum focus distance of the marumi about six iinches
I will have another try tommorrow it may just be that im not getting a high enough shutter speed and getting movement

Try flash? That's what I've been using this evening. It takes out the issue of movement. Then again, would you be getting movement with the Marumi but not with the tubes? Difficult to see why you would.

I've put these evening's examples in the same set at Flickr. They are the ones that are (for now, I keep adding to the set) at the end of the set, numbered 0659 69.01 to 69.16. There are 1100 pixel high versions of the whole frames, and 100% crops from the area I was focusing on. These examples are f/8 with the achromats on the Sigma 105. The names give more details of AF/MF and working distances.

They whole frame images need careful interpretation as in a couple of the pairs one side seems sharpest for the Marumi while the other side seems sharpest for the Raynox. It isn't clear to me what is going on there.

Looking at the 100% crops, on balance the Raynox crops look a bit better to me, but it is a very small sample. As in my previous G3 examples, autofocus seems to be working at least as well as manual focus (a bit better perhaps, but again it's a very small sample).

If you can capture images of a £2 coin perhaps you could do some comparisons between my results and yours. I can post some full size versions if you like - JPEG or the original RAWs.

I wouldn't be too quick to send it back - there might be technique issues, or some other complication. Look how difficult I'm finding it to pin down what is going on, and I'm used to achromats and these sort of magnifications.

 

[LCPete]

Thanks Nick
good point about flash it would remove doubt about shutter speed
I will set up a proper test tomorrow
Will use a 2 pound coin and put them up on here
I'll do the same again compare tube shots to achromat onea they should be similar in sharpness
to be honest tho when I set up using the marumi I couldn't get the image sharp in the viewfinder when zooming in to ten times on live view

 

[GardenersHelper]

I will set up a proper test tomorrow
Will use a 2 pound coin and put them up on here
I'll do the same again compare tube shots to achromat onea

Sounds good.

they should be similar in sharpness
to be honest tho when I set up using the marumi I couldn't get the image sharp in the viewfinder when zooming in to ten times on live view

Do you see the image sharp at 10x in live view using the tubes? (I've never used tubes.) I don't think I'd describe what I see at 10x as looking really sharp, even with the Sigma 105 without an achromat on it. I suspect that, irrespective of what the aperture is set to for the capture, we're looking at these images at f/2.8 on the viewfinder (well, f2.8 for the 100L/Sigma 105, f5.6 or whatever for some other lenses). The dof might be thin enough (depending on the subject and its shape) to make it look as though nothing in the image is particularly sharp. But there again, if you're seeing it much sharper with the tubes, which would presumably also be at f/2.8 (or whatever), then that is bad news as far as the Marumi goes.

I do find the image on the lcd looks a bit clearer with the Raynox, which seems to make it a bit easier than with the Marumi to see when I've got decent focus when I'm doing manual focus.

 

[LCPete]

Thanks Nick

I had another try this morning with more success, it was just my technique I used flash with a tripod
I manually focused through the veiwfinder
I used a two pound coin so that you can compare with your results
I will post them up later
I have only looked at them on the back of the camera but it does look like the marumi is ok I will have a look on the pc later and post them up

 

[LCPete]

It looks like the Marumi 200 is capable of sharp shots, it was just my poor technique!

taken with 7D Canon 100L macro with Marumi 200 at the minimum focus distance using flash at F8
on tripod used remote trigger
focus through viewfinder and checked in live view zoomed in
it did look sharp but was hard to tell to be honest as the light shining on the coin made the live view image difficult to view properly, reflections on the metal surface
I'm sure that an insect or similar wont have this problem
the focus point was just left of the middle of the image, the top of the centre circle of the £2 coin
the original is better than the uploaded version the centre of the coin is sharp but not the edges but I suspect that I haven't got things quite square
second image is the same one at 1600 by 1067
I did find focusing tricky and a bit hit and miss but did take a few and managed 1 in 3 sharp shots
am pleased in the end that the Marumi is OK

 

[GardenersHelper]

It looks like the Marumi 200 is capable of sharp shots, it was just my poor technique!

taken with 7D Canon 100L macro with Marumi 200 at the minimum focus distance using flash at F8
on tripod used remote trigger
focus through viewfinder and checked in live view zoomed in
it did look sharp but was hard to tell to be honest as the light shining on the coin made the live view image difficult to view properly, reflections on the metal surface
I'm sure that an insect or similar wont have this problem
the focus point was just left of the middle of the image, the top of the centre circle of the £2 coin
the original is better than the uploaded version the centre of the coin is sharp but not the edges but I suspect that I haven't got things quite square
second image is the same one at 1600 by 1067
I did find focusing tricky and a bit hit and miss but did take a few and managed 1 in 3 sharp shots
am pleased in the end that the Marumi is OK

Good news. Excellent. I'm relieved that you are pleased with the Marumi.

Here is one of my test shots, taken with very similar setup to yours. Flash using Marumi 200 on Sigma 105 on 70D at minimum focus distance, f/8, tripod used and wired remote shutter release. This is a version with no sharpening and resized to 1600 across to make comparison easier. However, mine is one of the ones where the coin wasn't parallel to the sensor, so the right hand side is much more in focus than the left, which makes comparison with your version a bit tricky. There might be some other complications too such as different illumination. That said, overall, to my eye, yours looks sharper than mine for the most part,

Welcome to the world of achromats. (A comparison with tubes would be interesting if you were inclined to do that.)


0659 69.08 2015_01_15 Marumi 200 on Sigma 105 on 70D F8 AF WD 75mm IMG_1049 LR removed sharpening 1600w by gardenersassistant, on Flickr

 

[LCPete]

Thanks Nick yes your's does look sharper on the right hand side
does look like both our marumi achromats work well with the DSLR which is great
just got to wait for spring to try them out properly
I will do some comparison shots with tubes
will take a few days before I've got the time
will be interesting though and I will try again without flash and make a note of the settings the tubes in theory should loose a stop of light
thanks again for your help

 

[GardenersHelper]

Thanks Nick yes your's does look sharper on the right hand side
does look like both our marumi achromats work well with the DSLR which is great
just got to wait for spring to try them out properly
I will do some comparison shots with tubes
will take a few days before I've got the time

No rush. When you're ready.

will be interesting though and I will try again without flash and make a note of the settings the tubes in theory should loose a stop of light

Depending on how many tubes you use, and which focal length lens you use them on. I think you lose a stop for each approx 41% increase in focal length.

Tubes have most effect with shorter focal length lenses I think, which makes me wonder which lens you will/might use the tubes with?

thanks again for your help

It's a pleasure. I think you know that though.

 

[LCPete]

Tubes have most effect with shorter focal length lenses I think, which makes me wonder which lens you will/might use the tubes with?



.

Will be with 100mm canon macro

I have also a Canon macro teleconverter called a life size converter that I bought secondhand its desinged to be used with the Canon 50mm macro that is a 1.2 lens as apposed to a 1:1 true macro to allow 1:1 close focus
I bought it to try out on the 100mm macro to give more magnification but its not compatible with the canon 100 but will try it out on the sigma 105
will try it out when i do the comparison with the tubes and achromat

 

[LCPete]

Hi Nick I've done some tests to try to compare the marumi M200 extension tubes (31 + 13 mm) and the Canon macro TC the Life Size converter
to be honest its very difficult to do a proper test partly just because Im not used to working at high magnification
the test did show that I found it easier to get consistent results with the tubes and Canon macro TC the Life Size converter I found it difficult to get sharp results with the Marumi it may just be that the achromat has a shallower depth of field
I think this shows in the marumi test shot being sharper at the bottom than the top, the coin may not have been quite square
I did try to line everything up but it was easier to get sharp shots with the tubes I got the shots first time
with the achromat I had several tries to get a good shot
I will have to try again in the spring with real insects in good light I think
the Marumi may come into its own then as it doesn't lose any light and I will be working with natural light so the loss of light with the tubes and converter may be an issue
I was hoping to do the test with my Sigma 105 as that would be more relevant to you but my adaptor ring hasn't arrived yet
I used a 550D with 100mmL macro with flash
F8 shutter speed 200 and ISO 200
I worked just off the minimum focus distance to avoid errors
I forgot to measure the distances but the Life Size converter had an added bonus of a greater working distance (than the Marumi) as did the tubes to a lesser extent
the marumi shot is the best one that I got and did struggle today to get sharp results with the achromat, sorry its not a very good comparison but at least you can compare your Marumi shots to my tube shots
hope you find these helpful was nice for me to see that the Life Size converter does work with my 100L ( I had read that its not compatible) and is a good option giving nice results and magnification
anyway heres the shots (1600 pixels wide)
first Marumi, second tubes then the Canon macro TC the Life Size converter

 

[GardenersHelper]

Hi Nick I've done some tests to try to compare the marumi M200 extension tubes (31 + 13 mm) and the Canon macro TC the Life Size converter
to be honest its very difficult to do a proper test partly just because Im not used to working at high magnification

As you know, I found it difficult too!

the test did show that I found it easier to get consistent results with the tubes and Canon macro TC the Life Size converter I found it difficult to get sharp results with the Marumi it may just be that the achromat has a shallower depth of field

I believe the dof is the same for the same aperture and same angle of view. I think this means that the Marumi is simply less sharp. To my eye the tubes version is much the sharpest/most detailed, with the Life Size converter second and the Marumi third.

I think this shows in the marumi test shot being sharper at the bottom than the top, the coin may not have been quite square

Same problem I had.

I did try to line everything up but it was easier to get sharp shots with the tubes I got the shots first time
with the achromat I had several tries to get a good shot

I found it difficult with the Marumi, but easier with the Raynox.

I will have to try again in the spring with real insects in good light I think
the Marumi may come into its own then as it doesn't lose any light and I will be working with natural light so the loss of light with the tubes and converter may be an issue
I was hoping to do the test with my Sigma 105 as that would be more relevant to you but my adaptor ring hasn't arrived yet
I used a 550D with 100mmL macro with flash
F8 shutter speed 200 and ISO 200
I worked just off the minimum focus distance to avoid errors
I forgot to measure the distances but the Life Size converter had an added bonus of a greater working distance (than the Marumi) as did the tubes to a lesser extent
the marumi shot is the best one that I got and did struggle today to get sharp results with the achromat, sorry its not a very good comparison but at least you can compare your Marumi shots to my tube shots
hope you find these helpful was nice for me to see that the Life Size converter does work with my 100L ( I had read that its not compatible) and is a good option giving nice results and magnification
anyway heres the shots (1600 pixels wide)
first Marumi, second tubes then the Canon macro TC the Life Size converter

Thanks for doing that Pete. That is very interesting. The point about losing light using tubes is interesting, and so the Marumi might help on that front. But if it turns out to be much less sharp than using tubes for insects then I doubt the extra stop or two of light will really help.

Does the Life size converter fit on the front of the lens (so it presumably doesn't lose light), or fit between the body and the lens (in which case it presumably does lose light)?

I've been using the Sigma 105 more. As I get more used to using it I'm finding it practical to use for more than I thought it would be practical for.

I've also tried a small number of real world comparisons of the Sigma 105 vs the 55-250 with achromats. These have been natural light shots of buds and flowers. As with the coins though, I'm finding it very difficult to get comparisons that I find fully convincing. This is partly because I've been doing sessions concentrating on using one or other of the setups. Although I'm keen in principle on getting some definitive comparisons, I quickly lose enthusiasm with the tedium of changing the setups (not too difficult) and then trying to line the shots up the same (surprisingly difficult). Also, a lot of the time I've been working with a breeze in not very bright light, which randomises the results especially with the small apertures I find I'm needing for the results I want to get, and hence slow shutter speeds. And unfortunately when the conditions have been better (still air in particular), I haven't been methodical enough about lining up shots sufficiently accurately, and have made mistakes like with the pair below, doing them with different framing (I had to crop the 55-250 version a bit to get it similar to the 105 version), different ISOs and different apertures, and 90 minutes apart so the light could well have been different. So that pair isn't really a fair comparison.

The difference in aperture in the pair below does raise a significant issue though. As mentioned above, I believe dof is the same for a given angle of view and aperture, but this pair seem to show a real world effect of something I noticed with my indoor still life comparisons - the Sigma 105 makes the somewhat OOF areas less OOF. Even though the Sigma used f/22 versus f/32 with the 55-250, it appears to have greater dof because of the slower drop off in sharpness/detail/contrast in the less in focus areas. It is possible of course that the 55-250 version lost a lot of sharpness from the diffraction effects of using f/32 rather than f/22, but given my earlier test results I doubt that is the main cause of the difference we can see here. (Incidentally, the reason for using the apertures I did was that in both cases I used a variety of apertures, and also variations in placing the centre of dof, trying to get as much in focus as I could, and these were the - to my eye - best results I got with each of the setups.)

Lots of caveats about this pair then, but flicking back and forth between the 1100 pixel high versions (available over at Flickr) the Sigma 105 version seems my better to my eye. In fact, it is sufficiently different that when my wife happened to look over my shoulder while I was doing the comparison she straight away said that in her view this single pair justified buying the Sigma. I didn't argue with that.

Raynox 150 on 55-250 STM on 70D, ISO 200, f/32, 1 sec

0662 05 2015_01_21 11-30 am 55-250 STM IMG_2126 LR 1100h by gardenersassistant, on Flickr

Sigma 105 on 70D, ISO 100, f/22, 1.6 sec

0662 06 2015_01_21 1pm Sigma 105 IMG_2217 LR 1100h by gardenersassistant, on Flickr

 

[LCPete]

As you know, I found it difficult too!



I believe the dof is the same for the same aperture and same angle of view. I think this means that the Marumi is simply less sharp. To my eye the tubes version is much the sharpest/most detailed, with the Life Size converter second and the Marumi third.



Same problem I had.



I found it difficult with the Marumi, but easier with the Raynox.



Thanks for doing that Pete. That is very interesting. The point about losing light using tubes is interesting, and so the Marumi might help on that front. But if it turns out to be much less sharp than using tubes for insects then I doubt the extra stop or two of light will really help.

Does the Life size converter fit on the front of the lens (so it presumably doesn't lose light), or fit between the body and the lens (in which case it presumably does lose light)?

I've been using the Sigma 105 more. As I get more used to using it I'm finding it practical to use for more than I thought it would be practical for.

I've also tried a small number of real world comparisons of the Sigma 105 vs the 55-250 with achromats. These have been natural light shots of buds and flowers. As with the coins though, I'm finding it very difficult to get comparisons that I find fully convincing. This is partly because I've been doing sessions concentrating on using one or other of the setups. Although I'm keen in principle on getting some definitive comparisons, I quickly lose enthusiasm with the tedium of changing the setups (not too difficult) and then trying to line the shots up the same (surprisingly difficult). Also, a lot of the time I've been working with a breeze in not very bright light, which randomises the results especially with the small apertures I find I'm needing for the results I want to get, and hence slow shutter speeds. And unfortunately when the conditions have been better (still air in particular), I haven't been methodical enough about lining up shots sufficiently accurately, and have made mistakes like with the pair below, doing them with different framing (I had to crop the 55-250 version a bit to get it similar to the 105 version), different ISOs and different apertures, and 90 minutes apart so the light could well have been different. So that pair isn't really a fair comparison.

The difference in aperture in the pair below does raise a significant issue though. As mentioned above, I believe dof is the same for a given angle of view and aperture, but this pair seem to show a real world effect of something I noticed with my indoor still life comparisons - the Sigma 105 makes the somewhat OOF areas less OOF. Even though the Sigma used f/22 versus f/32 with the 55-250, it appears to have greater dof because of the slower drop off in sharpness/detail/contrast in the less in focus areas. It is possible of course that the 55-250 version lost a lot of sharpness from the diffraction effects of using f/32 rather than f/22, but given my earlier test results I doubt that is the main cause of the difference we can see here. (Incidentally, the reason for using the apertures I did was that in both cases I used a variety of apertures, and also variations in placing the centre of dof, trying to get as much in focus as I could, and these were the - to my eye - best results I got with each of the setups.)

Lots of caveats about this pair then, but flicking back and forth between the 1100 pixel high versions (available over at Flickr) the Sigma 105 version seems my better to my eye. In fact, it is sufficiently different that when my wife happened to look over my shoulder while I was doing the comparison she straight away said that in her view this single pair justified buying the Sigma. I didn't argue with that.

Raynox 150 on 55-250 STM on 70D, ISO 200, f/32, 1 sec

0662 05 2015_01_21 11-30 am 55-250 STM IMG_2126 LR 1100h by gardenersassistant, on Flickr

Sigma 105 on 70D, ISO 100, f/22, 1.6 sec

0662 06 2015_01_21 1pm Sigma 105 IMG_2217 LR 1100h by gardenersassistant, on Flickr

Yes you are right the tubes do look to be the best option
I see what you mean even if I have to raise the ISO to maybe 1600 if the results are sharper and I have use noise reduction it will still be a better option

You're spot on about taking lots of shots of coins it soon gets tedious!
I can't wait to try out the tubes on real insects
When the adaptor ring arrives I will try again in the butterfly house with the sigma 105

Looking at your comparison between the zoom lens and raynox comparison I can see straight away that the Sigma 105 shot is better I can't put it into words it's just looks better , the light and detail is really good

Edit, looking again at the comparison shots between the 55-250 plus raynox and sigma 105 the out of focus areas look like the effect that you get with increasing focal length the longer focal length giving a more blurred background
I'm assuming that you used the same focal length for both maybe adding the achromat has the same effect of increasing the focal length on the out of focus areas

Edit again ! I forgot to say that the life size converter fits between camera and the lens
It's like a 1.2 TC with a built in tube

 

[GardenersHelper]

Edit again ! I forgot to say that the life size converter fits between camera and the lens
It's like a 1.2 TC with a built in tube

Ah. Thanks.

Edit, looking again at the comparison shots between the 55-250 plus raynox and sigma 105 the out of focus areas look like the effect that you get with increasing focal length the longer focal length giving a more blurred background
I'm assuming that you used the same focal length for both maybe adding the achromat has the same effect of increasing the focal length on the out of focus areas

He he. Nice one Pete. Here we go again. I did some more experiments.

First thing I did, before you made this comment, was to go back and do the dew-covered aquilegia again - fortunately it was still in much the same state today. I did it with the Raynox 150 on the 55-250 STM and with the Sigma 105, and this time I used the same ISO, aperture and (as near as I could get it) the same framing, first several with the Sigma, then several with the Raynox, and then several more with the Sigma. There was no significant difference amongst the Sigma shots or amongst the Raynox shots. The overall result was the same - the Sigma version looked better. Here is an example of each (as usual, the differences are clearer in the 1100 pixel high versions over at Flickr).

Raynox on 55-250 STM

0665 14 2015_01_25 70D + 55-250 STM + Raynox 150 IMG_2472 LR 1100h by gardenersassistant, on Flickr

Sigma 105

0665 15 2015_01_25 70D + Sigma 105 IMG_2473 LR 1100h by gardenersassistant, on Flickr

Looking closer confirms some earlier results. With a small aperture of f/22, the Raynox version is sharper at the point where the image was focused, but is less sharp/detailed/contrasty behind and in front of the focused area. And I much prefer the overall effect of the Sigma.


0665 22 2015_01_15 100pc crops at, behind and in front of focused area by gardenersassistant, on Flickr

However, as before, these used different focal lengths. I wondered what the effect would be if I shot the same scene with the Sigma 105 and the 55-250 STM without having an achromat on either of them, and using the same (or almost the same) focal length (100mm for the 55-250). Here is the scene. From left to right the bar codes go from front to back. I focused on the bar code on the marmalade jar.


0665 01 2015_01_25 70D + 55-250 STM at 100mm F5.6 IMG_2630 LR 1100h by gardenersassistant, on Flickr

As you can see from the same album over at Flickr, the results are pretty much identical, at all apertures the two lenses share, i.e. from f/5.6 to f/22. As an example, here is half of the image compared at f/8.


0665 13a 2015_01_25 50pc view comparison at F8 by gardenersassistant, on Flickr

One thing this illustrated is that the 55-250 really is quite sharp, like I've been reading about. I can't see any significant difference between it and the Sigma 105 in this test, which is pretty good going for a zoom lens against a macro prime.

So it looked like the only thing left to make the difference in the out of focus areas was the achromat. So I did another test, capturing the same scene with the Sigma 105, one version with the bare lens and one with a Raynox 105 on it. I did this from f/2.8 to f/22, twice, once using manual focus and the second time using autofocus for the first capture for each lens and then switching to manual focus and not altering the focus as I changed apertures. 1100 pixel high versions are here at Flickr.

It is the achromat that is making the difference. You can see it at all apertures. It is perhaps clearest at f/8, as illustrated in this comparison, (which shows the whole scene).


0666 29 2015_01_25 Bare Sigma 105 vs Sigma 105 + raynox 150 at F8 by gardenersassistant, on Flickr

This is a bit of a shocker for me. It might be cause for me to stop using achromats. I need to go into a huddle and have a think now, and do some research. I'm thinking extension tubes, teleconverters, MPE-65 (ironic, no?), flash units, ..... Have I gone round in a great big circle? Quite possibly.

 

[LCPete]

Ah. Thanks.



He he. Nice one Pete. Here we go again. I did some more experiments.

First thing I did, before you made this comment, was to go back and do the dew-covered aquilegia agai- fortunately it was still in much the same state today. I did it with the Raynox 150 on the 55-250 STM and with the Sigma 105, and this time I used the same ISO, aperture and (as near as I could get it) the same framing, first several with the Sigma, then several with the Raynox, and then several more with the Sigma. There was no significant difference amongst the Sigma shots or amongst the Raynox shots. The overall result was the same - the Sigma version looked better. Here is an example of each (as usual, the differences are clearer in the 1100 pixel high versions over at Flickr).

Raynox on 55-250 STM

0665 14 2015_01_25 70D + 55-250 STM + Raynox 150 IMG_2472 LR 1100h by gardenersassistant, on Flickr

Sigma 105

0665 15 2015_01_25 70D + Sigma 105 IMG_2473 LR 1100h by gardenersassistant, on Flickr

Looking closer confirms some earlier results. With a small aperture of f/22, the Raynox version is sharper at the point where the image was focused, but is less sharp/detailed/contrasty behind and in front of the focused area. And I much prefer the overall effect of the Sigma.


0665 22 2015_01_15 100pc crops at, behind and in front of focused area by gardenersassistant, on Flickr

However, as before, these used different focal lengths. I wondered what the effect would be if I shot the same scene with the Sigma 105 and the 55-250 STM without having an achromat on either of them, and using the same (or almost the same) focal length (100mm for the 55-250). Here is the scene. From left to right the bar codes go from front to back. I focused on the bar code on the marmalade jar.


0665 01 2015_01_25 70D + 55-250 STM at 10mm F5.6 IMG_2630 LR 1100h by gardenersassistant, on Flickr

As you can see from the same album over at Flickr, the results are pretty much identical, at all apertures the two lenses share, i.e. from f/5.6 to f/22. As an example, here is half of the image compared at f/8.


0665 13a 2015_01_25 50pc view comparison at F8 by gardenersassistant, on Flickr

One thing this illustrated is that the 55-250 really is quite sharp, like I've been reading about. I can't see any significant difference between it and the Sigma 105 in this test, which is pretty good going for a zoom lens against a macro prime.

So it looked like the only thing left to make the difference in the out of focus areas was the achromat. So I did another test, capturing the same scene with the Sigma 105, one version with the bare lens and one with a Raynox 105 on it. I did this from f/2.8 to f/22, twice, once using manual focus and the second time using autofocus for the first capture for each lens and then switching to manual focus and not altering the focus as I changed apertures. 1100 pixel high versions are here at Flickr.

It is the achromat that is making the difference. You can see it at all apertures. It is perhaps clearest at f/8, as illustrated in this comparison, (which shows the whole scene).


0666 29 2015_01_25 Bare Sigma 105 vs Sigma 105 + raynox 150 at F8 by gardenersassistant, on Flickr

This is a bit of a shocker for me. It might be cause for me to stop using achromats. I need to go into a huddle and have a think now, and do some research. I'm thinking extension tubes, teleconverters, MPE-65 (ironic, no?), flash units, ..... Have I gone round in a great big circle? Quite possibly.

its really interesting that the zoom is so good
i cant see any difference in the test shots
i have read good things about it
sounds like it would make a great dragonfly lens
i have thought about getting it in addition to my 70-200 for the IS but i dont see enough dragonflies to justify getting it
i guess for both of us to get high mag tubes with the macro lens is the best option
Im not sure why but i found the tubes much easier to focus with than the achromat
i could get a sharp shot first try with the tubes but the achromat took a few tries to get an in focus shot, that reason on its own is enough to make me think that tubes are the best option
the achromat will be handy to keep in the bag just in case though
again your sigma 105 shots do look better than the achromat ones
you have gone round in a circle but at least you have got it figured out now what will work best for you

 

[GardenersHelper]

its really interesting that the zoom is so good
i cant see any difference in the test shots
i have read good things about it
sounds like it would make a great dragonfly lens
i have thought about getting it in addition to my 70-200 for the IS but i dont see enough dragonflies to justify getting it

Yes, I think it is good too. Sharp and not too heavy (being EF-S). Not as much reach as I'd like, but you can't have everything!

i guess for both of us to get high mag tubes with the macro lens is the best option
Im not sure why but i found the tubes much easier to focus with than the achromat
i could get a sharp shot first try with the tubes but the achromat took a few tries to get an in focus shot, that reason on its own is enough to make me think that tubes are the best option
the achromat will be handy to keep in the bag just in case though
again your sigma 105 shots do look better than the achromat ones
you have gone round in a circle but at least you have got it figured out now what will work best for you

Ha ha. Not so quick Pete. You know me - it's never straightforward. And, I can be rather obtuse and miss obvious things like, it turns out, I did in my last post.

It is the achromat that is making the difference. You can see it at all apertures. It is perhaps clearest at f/8, as illustrated in this comparison.....

Well, it was an obvious conclusion to draw. But wrong, unfortunately.

I started looking at tubes, extenders etc last night, but I woke up early this morning still puzzled about what I had discovered yesterday. And then it struck me - I had forgotten about effective aperture. The test image I used yesterday was at 1:1, and on the Sigma 105 that halves the effective aperture (at 1:1 a nominal f/22 is an effective f/45, and it is the effective aperture which counts for dof and diffraction losses). The 55-250 + Raynox would not be affected in this way - it's nominal f/22 would also be an effective f/22. Could it be, I wondered, that what I was seeing was the result of the Sigma used a larger effective aperture? That would increase the diffraction losses, which might explain why the focused-on areas were less sharp with the Sigma than the 55-250 + Raynox, and the smaller effective aperture would also increase the dof, which might explain why the less in focus areas were sharper/better defined/had more clarity with the Sigma. So how much was it a matter of effective aperture, and how much the affect of using an achromat?

So of course I did another comparison. And it turned out to be very revealing indeed.

I went back to the same little aquilegia, still with lots of lovely dew drops on it. After some head scratching, calculations and preliminary tests, I decided to capture the following images (three of each - I picked the best of each, but there was hardly any difference between the ones in each triplet).

• 70D with Sigma 105 at 1:1, f/22
• 70D with Sigma 105 at 1:1, f/11
• 70D with 55-250 STM and Raynox 150, f/22, focal length just over 200mm, which produces 1:1 (It was actually 218mm, but I could only discover that afterwards, on the PC)
• 70D with 55-250 STM and Raynox 150, f/22, focal length just over 100mm, which produces 1:2 (actually 100mm)
• G3 + 45-175 and Raynox 150, f/22, framed to match the 1:1 shots (except the G3 has a 4:3 aspect ratio rather than the 3:2 of the 70D, so it was a bit of an approximation)
• G3 + 45-175 and Raynox 150, f/22, framed to match the 1:2 shot (another approximation)
• FZ200 + Raynox 150, f/8 (minimum aperture, similar to f/22 on the other rigs), framed to approximately match the 1:1 shots (but also 4:3)
• FZ200 + Raynox 150, f/8, framed to approximately match the 1:2 shot.

1100 pixel high versions of these images (which have all had the same, modest import adjustments in Lightroom) are available in this set over at Flickr, along with larger versions of the composite comparison shots shown below.

Today's mistake: I captured the 70D images using ISO 400. This was to get the shutter speed of the first shot down from about 6 seconds at ISO 100 to about 1.5 seconds. I wanted to do this because it was a bit breezy and I had a better chance of exploiting calm moments with a shorter exposure. I used ISO 100 on the FZ200. That is fair because of the equivalences involved, but by mistake I used base ISO of 160 for the G3 rather than ISO 400, which would have been fairer. As it happens, and fortunately, I don't think this made any significant difference to what I was interested in with these comparisons.

Here is a comparison of the Sigma 105 f/22 and f/11 shots. As you would expect, the f/22 shot has greater dof - it has better sharpness/detail/clarity/contrast or whatever both in front of and behind the plane of best focus. However, it is less sharp right in the middle of the image, which is where I focused. (For the other shots I tried to focus on the same area of little droplets, irrespective of whether it was exactly in the middle of the image or not. (Aligning these comparison shots is, as I think you've discovered, not as easy as one might imagine before trying it!)

In these comparisons I have shown the left side of the image as this has a better distribution of distances to the sensor and so shows dof etc differences more clearly.


0667 12 2015_01_26 Comparing Sigma 105 at F22 and F11 by gardenersassistant, on Flickr

Because this was 1:1, the effective aperture for the f/22 shot was f/45, and the effective aperture for the f/11 shot was f/22.

Here is a comparison of the top half of the f/11 Sigma shot (effective aperture f/22), with the 55-250 + Raynox 150 shot framed to match the Sigma's 1:1. This used f/22, which is also the effective aperture. There are similar comparisons for the G3 and FZ200 at their minimum apertures of f/22 and f/8, and both of these are also the effective apertures. In these top half shots we get a decent view of the focused-on area and the softer areas behind it.


0667 13 2015_01_26 Comparing - top half of image - Sigma 105 at F11 with 55-250 at F22, G3 at F22, FZ200 at by gardenersassistant, on Flickr

And similarly for the bottom half of the image, where we can see the focused-on area and some softer areas in front of it.


0667 14 2015_01_26 Comparing - bottom half of image - Sigma 105 at F11 with 55-250 at F22, G3 at F22, FZ200 by gardenersassistant, on Flickr

To my eye all four of these look rather similar in terms of dof distribution and sharpness/clarity/contrast. (The colours don't look similar. I created a camera profile for each camera from colour chart reference images captured just before capturing the test series, but even with these applied, and applying the white balance from these camera-specific reference shots, the colours were wildly different. I tried setting all of the images with the same white balance, but that just made them vastly different in different ways. So I played manually with the white balance to try to some semblance of similarity but gave up after a few minutes of faffing around. These are the colours I had got to when I lost patience with it. Needless to say, I find this hugely disappointing.)

I cropped the three 1:2 images to make the framing match the 1:1 images (as best I could), "cropping for dof". In the previous comparison the effective aperture for all four shots was roughly f/22 in APS-C terms. In this comparison the effective aperture for all four shots is roughly f/45 in APS-C terms.


0667 15 2015_01_26 Comparing - top half of image - Sigma 105 at F22 with versions cropped from 1to2 to 1to1 by gardenersassistant, on Flickr


0667 16 2015_01_26 Comparing - bottom half of image - Sigma 105 at F22 with versions cropped from 1to2 to 1 by gardenersassistant, on Flickr

Once again, these look rather similar to me.

Finally, here is a comparison of effective f/45 versus effective f/22 for the two 70D setups.


0667 17 2015_01_26 Comparing F45 equivalent 70D shots and F22 equivalent 70D shots by gardenersassistant, on Flickr

Again, to my eye, the differences between left and right (f/45 and f/22) look rather similar for both setups.

So, I think a large part of the better look of yesterday's bare Sigma shots compared to the shots (with the Sigma and the 55-250) using an achromat arose from differences in the effective aperture, not because I was using an achromat.

Does that explain all of the differences? I'd be interested in your views as to how much better (or not) the Sigma shot looks compared to the others in these comparisons.

In the meantime, I'm not going to give up using my achromats just yet, or my FZ200 and G3. (In fact, before I had looked at these images and worked through the comparisons I spent some time out in the garden with the FZ200. I had forgotten what a delight I find it to use. Don't know that the quality will be brilliant, but there again the conditions were not good and I suspect I wouldn't have got great results with any of my rigs. It was nice though to do some free form "looking for pretty pictures" rather than yet more tedious tests.)

 

[LCPete]

Hi Nick very interesting it looks like there's more going on than we thought
A lot to think about I'm too tired to think today but will reply properly soon

 

[GardenersHelper]

Hi Nick very interesting it looks like there's more going on than we thought
A lot to think about I'm too tired to think today but will reply properly soon

No rush. I need a rest from it myself. Too much of this comparative/analytic stuff is bad for the soul.