Raynox lens and Canon EF 75-300mm F4.0-5.6 III

[davholla]

I am fed up with my Canon MPE65 lens. It needs fixing again - only 4 months after the last time.
I need to know that if I go on holiday my extreme macro lens will definitely work.
I already have a Canon EF 75-300mm F4.0-5.6 III and if this is correct

Using Raynox Adapters For Extreme Macro

Raynox macro adapters are not only by far and away the best way to start doing extreme macro, but you can even stack them and use them as tube lenses too

extreme-macro.co.uk

If I get a DCR 150 & DCR 250 I should be able to use it for a macro lens with 1-5 magnification. Any thoughts?

Are my calculations correct? Good place in the UK to buy these?
Also does anyone know if I can buy these and return if not any good? If so where from?

 

[GardenersHelper]

Here are some measurements. The Sigma 70-300 has a strange close-up mode. I didn't use that.

The numbers are in pairs, first infinity focus, second closest focus. What you get for the closest focus values will depend on how close your 75-300 focuses.


Magnifications with Raynox 150 and 250 on Sigma 70-300 by gardenersassistant, on Flickr

Looks like purchase may have to be from Amazon or eBay. Searching for 'Raynox" at Jessops, Wex, London Camera Exchange and Clifton cameras comes up with "no results found".

 

[davholla]

Thanks for that, I have the Canon 70-300 mm - do you think that would be any difference? Also do you think this will work?

 

[GardenersHelper]

Thanks for that, I have the Canon 70-300 mm - do you think that would be any difference? Also do you think this will work?

Assuming you are using APS-C, I wouldn't expect the infinity focus values (the first one in each pair) to be much different. The closest focus values will depend on how close the 70-300 will focus. I have a hunch that may be similar to the 75-300 (when not used in its strange close-up mode, which I didn't use). But that is pure guesswork. This can all be rather variable and equipment-specific (on which, see my final point below).

As to whether you will get usable autofocus or not is highly dependent on the camera lens. It didn't work well with the 150 or at all with the 250 on the first Canon EF-S 55-250 I used them on, but when I replaced that with a later model (I think there were three models and I moved to the latest of them) AF worked fine with the 150 and the 250. If it does work, AF may not be as good with the 250 as the 150, and not so good again if you stack them. (As far as I recall it worked ok for me with stacked 150+250 and 250+250, not that I used either of those combinations a lot, but tbh I don't recall if that was with the Canon setup or one of my micro four thirds setups. Or even perhaps one of my bridge cameras.)

I wouldn't expect the image quality to be as good as with the MPE-65, especially at the higher magnifications. I don't know how much difference it would make in practice, given that you'll probably be well into in diffusion softening territory anyway, and that evens things out somewhat as far as image quality goes. I might do some banknote comparison tests to have a look at that, although translating those tests into practical differences out in the field can be a bit iffy. Still, it might be reassuring, or on the other hand it might give a clear warning.

On the subject of diffraction, be aware that effective aperture works very differently with close-up lenses. With the MPE-65 you use the formula of effective aperture = nominal aperture * ( 1 + magnification), where "nominal aperture" is the aperture you set on the camera/lens. So if you set the aperture to f/5.6 at 5:1 you are actually using f / ( 5.6 * ( 1 + 5 ) ) = f/32.

With close-up lenses the effective aperture doesn't change with magnification. You get what you set as far as effective aperture goes. That means that if the maximum f-number on the 70-300 is f/22, then that is the largest f-number you can use, and that gives you the largest DOF you can get to. So for example with stacked 250s at 5:1 you couldn't get as much DOF as you could with the MPE-65 at f/5.6. And of course you can go up to f/16 with the MPE-65, giving you much greater DOF, at the cost of a lot more loss of fine detail from diffraction softening.

That is the reason I've started using the setup I'm using now, because I couldn't get as much DOF as I wanted with my close-up lens setups, especially at higher magnifications. Another reason perhaps to consider my final suggestion below.

I've updated the table to include two Raynox 250s stacked. With the Sigma this gets to 5:1. Be aware though that when stacking close-up lenses you go straight to the working distance of the stacked pair. That means for example that with this setup, for anything greater than 2.8X (with a single 250) you would immediately drop to a working distance of around 45mm with two stacked 250s, rather than the working distance steadily decreasing as the magnification goes up. At 5:1 though the working distance is no worse than with the MPE-65 which is I think around 40mm. The diameter of a Raynox setup is also smaller than the diameter of the MPE-65, which means you can get a bit shallower angle on the subject.


Magnifications with Raynox 150 and 250 on Sigma 70-300 by gardenersassistant, on Flickr

I wonder if it might be worth spending £10-15 on a cheap 4-piece close-up filter set. You won't like the image quality, but it would let you try out the sort of magnifications and working distances you would get with the 150 and 250 and the 150+250 and 2x250 stacked on the 70-300. It would be a sunk cost, but if it turns out not to work, or you don't like the way you have to use it, it could save you £120 or so. I suppose it depends on your seller's returns policy, and also how long it will take you to work out whether it is working or not. It may take you a while to get your hand in with a close-up lens approach, and that may take you outside of the return period.

 

[davholla]

Thanks for that, the quality is something I had not thought about. I like MPE65 but I just don't think it is reliable. I don't really want to buy another one - a bit expensive really to have two of them.

 

[GardenersHelper]

I wouldn't expect the image quality to be as good as with the MPE-65, especially at the higher magnifications. I don't know how much difference it would make in practice, given that you'll probably be well into in diffusion softening territory anyway, and that evens things out somewhat as far as image quality goes. I might do some banknote comparison tests to have a look at that, although translating those tests into practical differences out in the field can be a bit iffy. Still, it might be reassuring, or on the other hand it might give a clear warning.

I've done some banknote comparisons. As always, I might have messed it up, but there seems to be a very clear message from it - don't go down the close-up lens route.

Using flash, I captured banknote images at 1X, around 2.8X and 5X using the MPE-65 on a Canon 70D, using effective apertures of f/11 and f/22 for each magnification. I then captured matching images using, respectively, a Raynox 150, a Raynox 250 and two Raynox 250s on a Sigma 70-300 on the 70D.

The results from the Sigma at 2.8X and 5X were so poor that I wanted to find out it the problem was with the Sigma (which I haven't used much and so don't have any feel for) or the use of close-up lenses. So I repeated the captures using a Raynox 150, Raynox 250 and two Raynox 250s on a Canon EF-S 55-250 on the 70D. This is a lens I have used a lot and have felt the images I captured with it using a 150 and 250 have been ok. I'm not sure I ever used it with stacked close-up lenses. I couldn't quite match the magnifications, and I made a mistake of one stop with the aperture for the pair of 5Xish captures, but the overall picture seemed pretty clear. The results were no better than with the Sigma. I'm rather surprised about this, given that I got some nice results with the 55-250 and Raynox 150 and 250 on the 70D, but unless I really messed up the tests in some way, for both the Sigma and the Canon 55-250, the conclusions seem clear to me.

Incidentally, these poor results from the close-up lenses are consistent with the fact that I was using 10X screen magnification in manual focus mode to try to get the focus spot on, but I found this a lot more difficult to do with the Sigma and the 55-250 than with the MPE. Despite using a tripod, at 2.8X and 5X magnification and using 10X screen magnification the focus bobbled around madly when I touched the camera to change the focus, with the image going in and out of focus. And when I let go of the camera it settled to a different place from where I had set the focus, so it was a try and try again thing to try to get it to settle at the right place. With the MPE-65 the textures on the banknote would show up clearly when the rig settled in the right place. With both close-up lens setups I only got a very soft view on the screen which never showed me the textures like the MPE did, so there was an element of guesswork about exactly when it was in best focus.

I only took one shot for each combination rather than using repetition as I usually do and picking the best one. There can be a lot of shot to shot variation with these tests. However, the overall picture is so clear and consistent that I think it unlikely that shot to shot variation is masking the underlying picture of what is going on.

Here are six comparisons. I shot raw and processed using my usual pipeline of PhotoLab, Lightroom and DeNoise AI, using the same presets in each case, and no hand-crafting on top of that. This is very strong processing (which I use for my much softer, tiny aperture shots) and it resulted in the MPE images being over-processed, but I don't think that changes the overall interpretation.

These comparisons show 1300 pixel high versions at 100%. The differences are so large that they show up here at my normal output size. There is no need to pixel peep looking for subtle differences. The MPE is on the left, the Sigma in the middle and the Canon 55-250 on the right.

For 1X and 2.8X I shot the Sigma at f/11 and f/22. I adjusted the f-numbers of the MPE according to the magnification to give matching effective apertures of f/11 and f/22. For the 5X pairs I shot the Sigma at f/16 and f/32 because f/16 was the largest effective aperture I could get with the MPE at 5X (f/2.8 * (1+5))=f/16). I shot the Canon 55-250 at f/11 and f/22 for all three pairs, having forgotten to use f/16 and f/32 for the 5Xish shot. (I couldn't quite get to 5X with the 55-250, and similarly I couldn't quite match the 2.8X shot, but I think both are near enough to tell the story ok.)

Click through to Flickr to see the 1300 pixel high versions and click again once there to get them full size. That makes the differences show up much clearer than here.

Magnification 1X, effective aperture f/11.

1838 7.1 3-way 1X effectiveF11 100pc of 1300h by gardenersassistant, on Flickr

Magnification 1X, effective aperture f/22

1838 7.2 3-way 1X effectiveF22 100pc of 1300h by gardenersassistant, on Flickr

Magnification around 2.8X (less for the Canon 55-250), effective aperture f/11

1838 7.3 3-way 2.8Xish effectiveF11 100pc of 1300h by gardenersassistant, on Flickr

Magnification around 2.8X (less for the Canon 55-250), effective aperture f/22

1838 7.4 3-way 2.8Xish effectiveF22 100pc of 1300h by gardenersassistant, on Flickr

Magnification around 5X (less for the Canon 55-250), effective aperture f/16 (f/11 for the 55-250)

1838 7.5 3-way 5Xish effectiveF16,F16,F11 100pc of 1300h by gardenersassistant, on Flickr

Magnification around 5X (less for the Canon 55-250), effective aperture f/32 (f/22 for the 55-250)

1838 7.6 3-way 5Xish effectiveF32,F32,F22 100pc of 1300h by gardenersassistant, on Flickr

 

[davholla]

Thanks for that. Some people do get good images though. I am confused. I just cleaned the contacts and it is working now - but I did that the other day and it didn't last long! Maybe this time will be different.