Age old question - Best studio lens

donkeymusic

donkeymusic

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Carlo
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After some time, earlier this year i decided to purchase a Sigma 70-200 for use in the studio, thinking being that i could get closer to children when shooting without being in their face.

Over the past few weeks and recent shoots i have noticed that when i am shooting at 200, i am getting to much blur and missing some good shots, i thought it mis-focusing but now thinking that its down to the the range and camera shake, so wonder how best to overcome this and at the same time what lens you all use in the studio as your "must have" lens

Thanks
 
How big is your studio? a 70-200 is perfect on a FF body, but a bit long on a crop unless you have lots of nice space. Have you checked the lens at 200mm to be sure it's functioning properly? Can you post a shot with this blur?
 
If you Google it there are quite a few reports of the Sigma being slow to autofocus - which could make thinks tricky at close range in a studio.
 
I think that your comments regarding camera shake are probably the reason for the blur. I've got the same lens and it's very big and very heavy, Im dreading having to use it for any length of time, I think a new technique of holding it will certainly help me.
 
The23rdman said:
How big is your studio? a 70-200 is perfect on a FF body, but a bit long on a crop unless you have lots of nice space. Have you checked the lens at 200mm to be sure it's functioning properly? Can you post a shot with this blur?
Click to expand...
can post sample sots at various lengths this evening
 
Ozei said:
If you Google it there are quite a few reports of the Sigma being slow to autofocus - which could make thinks tricky at close range in a studio.
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It does seem fine with auto focus, never had any reason to question this
 
nikon.norm said:
I think that your comments regarding camera shake are probably the reason for the blur. I've got the same lens and it's very big and very heavy, Im dreading having to use it for any length of time, I think a new technique of holding it will certainly help me.
Click to expand...

Used it for some time and not had any issues with the weight.
 
donkeymusic said:
two examples,

whats the problem with them?
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With the head and shoulders of the lad, it looks like miss-focusing. DoF is very shallow and sharpest point appears to be around the collar, ie behind the face.

The other possibility is camera-shake, but unlikely I think. Depending on the flash heads and power setting, the effective flash duration could be as low as 1/300sec or so in terms of equivalent shutter speed, and that might be marginal at the longer end of a 70-200 zoom. Image stabilisation should fix it, though of course not if it's subject movement rather than camera shake.
 
Thanks for your reply

I am using f8 which I presumed would have given me enough dof to get the whole subject in focus?

I always attempt to lock my focus on the subjects eyes.

I don't think there is much camera shake even with the size of the lens. I am using lencarta flash heads, flash duration 1/125th.

How would I use image stabilisation?
 
donkeymusic said:
Thanks for your reply

I am using f8 which I presumed would have given me enough dof to get the whole subject in focus?

I always attempt to lock my focus on the subjects eyes.

I don't think there is much camera shake even with the size of the lens. I am using lencarta flash heads, flash duration 1/125th.

How would I use image stabilisation?
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If you're wanting the whole head and shoulders sharp, then you need more DoF. The zip is sharp, the shoulders aren't, and neither is the face that is a little nearer the camera. But there's enough DoF to get the eyes and face sharp with accurate focusing. With quite mobile subjects like that young lad, you need to focus and refocus constantly as very small changes of distance will throw it out. Maybe try servo-AF, selecting a single focus point positioned over the eyes.

I don't think it's camera shake or subject movement either, just missed focus. Your flash duration is not 1/125sec, that's your shutter speed - they're not the same thing. The latest version of Sigma's 70-200/2.8 has image stabilisation, Sigma calls it OS for Optical Stabilisation.
 
Re DOF: remember that as you get effectively closer due to zooming in the f8 that was fine at 70mm becomes much narrower at 165mm. That close you'll need f16 to get close to all in focus.

I think Hoppy has given you some great advice as always, but I wouldn't use IS with kids - I've never found it useful. No, the trick is servo mode and taking lots and lots of shots accepting that many will miss critical focus.
 
There's some personal preference in the best way to go about focusing something like this, though FWIW I probably wouldn't use servo AF myself for that, but instead use a single AF point over one of the eyes and just keep checking and rechecking focus very frequently, AF switched to the back-button. The problem with servo AF is that if the focus point slips on to the background for any reason (quite likely) then it will immediately try and focus on that and start shunting around. It can take a frustrating second or two to get it back.

I (almost) always use IS. It can't do any harm and even when you don't technically need it, it stabilises the viewfinder and makes accurate framing a little bit easier if you're trying to get that AF point accurately positioned.
 
Something like 85, 135 or 100mm prime would be my choice. 70-200 is good but a bit hefty for that work.

Your issues sound like slow sync speed. At 1/250s it is not so bad, but I realise 5D will only do 1/200s. Any less and you risk some extra blur, particularly if ambient shows through. Focusing may be an issue. You should be happy shooting headshots at f/1.8. OK, if they stretch their hands and everything you need a fair bit more DOF
 
daugirdas said:
Something like 85, 135 or 100mm prime would be my choice. 70-200 is good but a bit hefty for that work.

Your issues sound like slow sync speed. At 1/250s it is not so bad, but I realise 5D will only do 1/200s. Any less and you risk some extra blur, particularly if ambient shows through. Focusing may be an issue. You should be happy shooting headshots at f/1.8. OK, if they stretch their hands and everything you need a fair bit more DOF
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Sync speed is not an issue here. 1/125sec is a good default for studio work when using longer-duration studio heads, regardless of max x-sync speed, even if there is a modest amount of ambient light around. Check camera handbook on this - Canon suggests 1/60sec.
 
HoppyUK said:
If you're wanting the whole head and shoulders sharp, then you need more DoF. The zip is sharp, the shoulders aren't, and neither is the face that is a little nearer the camera. But there's enough DoF to get the eyes and face sharp with accurate focusing. With quite mobile subjects like that young lad, you need to focus and refocus constantly as very small changes of distance will throw it out. Maybe try servo-AF, selecting a single focus point positioned over the eyes.

I don't think it's camera shake or subject movement either, just missed focus. Your flash duration is not 1/125sec, that's your shutter speed - they're not the same thing. The latest version of Sigma's 70-200/2.8 has image stabilisation, Sigma calls it OS for Optical Stabilisation.
Click to expand...

Thanks for your response.

As they are children i primarily shoot, i think at the moment i need as much as possible in focus. I do always aim to focus on the eyes and refocus each time to allow for movement. I would have expected that F8 would have give me enough dof to get all in focus even if i was to focus on the nose.

I will need to check but im pretty sure that i only use a single focus point. I also think that i have IS/OS enabled.

Sorry i did know that shutter speed is 1/125, but i dont the flash duration.
 
The23rdman said:
Re DOF: remember that as you get effectively closer due to zooming in the f8 that was fine at 70mm becomes much narrower at 165mm. That close you'll need f16 to get close to all in focus.

I think Hoppy has given you some great advice as always, but I wouldn't use IS with kids - I've never found it useful. No, the trick is servo mode and taking lots and lots of shots accepting that many will miss critical focus.
Click to expand...

I think maybe i do need to take more photos but the refresh rates of the flash seems to be slow and although i can fire through the shots the light is not as bright, does that make sense?
 
HoppyUK said:
There's some personal preference in the best way to go about focusing something like this, though FWIW I probably wouldn't use servo AF myself for that, but instead use a single AF point over one of the eyes and just keep checking and rechecking focus very frequently, AF switched to the back-button. The problem with servo AF is that if the focus point slips on to the background for any reason (quite likely) then it will immediately try and focus on that and start shunting around. It can take a frustrating second or two to get it back.

I (almost) always use IS. It can't do any harm and even when you don't technically need it, it stabilises the viewfinder and makes accurate framing a little bit easier if you're trying to get that AF point accurately positioned.
Click to expand...

I will check for Servo AF when i get in but sure i use this, how does AF switched to back button work?
 
Check how much DoF you're getting here http://www.dofmaster.com/dofjs.html though bear in mind that these distances are based on a standard size print viewed from a standard distance, eg 10in print viewed from about 12in. If you blow it up big on screen and view more closely, DoF will reduce. The tables also assume an uncropped image - if you crop, DoF increases.

Don't worry about flash duration, but stick to 1/125sec shutter speed.

Back-button AF varies with camera model, but most have the option (enabled in menus) of removing AF from the shutter release so it only works when the back/rear AF button is pressed. Many people prefer it. Quite a few threads on this if you search.

From what you've show, simple answer seems to focus more carefully and more often, and raise the f/number. You may lose a little bit of ultimate sharpness doing this, due to aperture defraction, but it will only be slight and a worthwhile trade-off for the extra safety margin.
 
HoppyUK said:
Check how much DoF you're getting here http://www.dofmaster.com/dofjs.html though bear in mind that these distances are based on a standard size print viewed from a standard distance, eg 10in print viewed from about 12in. If you blow it up big on screen and view more closely, DoF will reduce. The tables also assume an uncropped image - if you crop, DoF increases.

Don't worry about flash duration, but stick to 1/125sec shutter speed.

Back-button AF varies with camera model, but most have the option (enabled in menus) of removing AF from the shutter release so it only works when the back/rear AF button is pressed. Many people prefer it. Quite a few threads on this if you search.

From what you've show, simple answer seems to focus more carefully and more often, and raise the f/number. You may lose a little bit of ultimate sharpness doing this, due to aperture defraction, but it will only be slight and a worthwhile trade-off for the extra safety margin.
Click to expand...

Once again thanks for your reply,

just had a look at the link you posted. and attached a screenshot of what i think i am getting which basically says that my dof is 0.14 inch, so from that if my focus isnt spot on then im always gonna be out of focus, but surely at such a small distance everything would appear out focus, think i may be getting slightly confused here/

i do always use 1/125sec shutter speed

I know i have it on my camera but was not sure how this affected the focus.

I am planning on trying F11 to test this.
 
donkeymusic said:
Once again thanks for your reply,

just had a look at the link you posted. and attached a screenshot of what i think i am getting which basically says that my dof is 0.14 inch, so from that if my focus isnt spot on then im always gonna be out of focus, but surely at such a small distance everything would appear out focus, think i may be getting slightly confused here/

i do always use 1/125sec shutter speed

I know i have it on my camera but was not sure how this affected the focus.

I am planning on trying F11 to test this.
Click to expand...


Not quite, you have 0.14ft of DoF, which is 1.7in or a bit over 4cm.

Yes, that's not a lot and will make things tricky even if the distance changes only slightly - remember that's both subject and/or camera moving.

Do some tests at f/8, f/11, and f/16 - see what you get. But you've reduced DoF a lot there by zooming in for a tight head & shoulders of a small lad.
 
donkeymusic said:
I think maybe i do need to take more photos but the refresh rates of the flash seems to be slow and although i can fire through the shots the light is not as bright, does that make sense?
Click to expand...

What body are you using? Up the ISO a bit to get some more leeway. Using lights allows you to get away with higher ISO than natural light.
 
The23rdman said:
What body are you using? Up the ISO a bit to get some more leeway. Using lights allows you to get away with higher ISO than natural light.
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:thinking:
 
HoppyUK said:
:thinking:
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Well... that's right as far as I know :D and with lots of light even ISO 3200 shots from my G1 look lovely. Why you'd want to is another question but I'm sure where there's a possibility there are people who will.
 
It's true and that's why DPReviews high iso studio tests are useless. I'm not talking about using uber high iso, but on a decent body 400 or so will look just great, and its possible to get away with higher.
 
I use a Canon 70-200mm F4 on a 5D2 for my studio portraits of kids.
If its any assistance to you when I do close ups (head/shoulders) shots I can get away with 1/125 at F10 - ISO 100 and thats with the Lencarta smartflash on full power.
When doing the close ups I try not to venture over 135mm (sometimes easier said than done)
 
woof woof said:
Well... that's right as far as I know :D and with lots of light even ISO 3200 shots from my G1 look lovely. Why you'd want to is another question but I'm sure where there's a possibility there are people who will.
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Well it's certainly not true as stated.

However, noise is directly related to photon capture and amplification, so if there are naturally more photons in the image, such as a high-key or mostly light-toned studio shot (common these days) then less noise will be visible. But the same shot lit by daylight, if possible, would be exactly the same and you can't take liberties in the studio as seems to be implied. With darker toned subjects or any under-exposure, you'll see noise for sure, and furthermore, larger areas of plain tone as is common with studio backgrounds show noise more noticeably than detailed subjects.

As for DPR's ISO tests, I thought they made a point about using tungsten light for those, as it's closer to reality for a lot of high ISO scenes. Warmer light can lead to more visible noise than daylight or flash, as the blue channel needs extra amplification and can therefore appear noisier.
 
That may be true about dpreview.

As stated I wasn't suggesting he stuck it on ISO 3200, Richard, just that the quality of light under studio conditions should mean he could get away with higher than base iso.
 
HoppyUK said:
Well it's certainly not true as stated.

However, noise is directly related to photon capture and amplification, so if there are naturally more photons in the image, such as a high-key or mostly light-toned studio shot (common these days) then less noise will be visible. But the same shot lit by daylight, if possible, would be exactly the same and you can't take liberties in the studio as seems to be implied. With darker toned subjects or any under-exposure, you'll see noise for sure, and furthermore, larger areas of plain tone as is common with studio backgrounds show noise more noticeably than detailed subjects.

As for DPR's ISO tests, I thought they made a point about using tungsten light for those, as it's closer to reality for a lot of high ISO scenes. Warmer light can lead to more visible noise than daylight or flash, as the blue channel needs extra amplification and can therefore appear noisier.
Click to expand...

It is true. At least what I posted is. Maybe I shouldn't have posted, but you know me, sometimes I can't resist... but I'll clarify what I said...

It is true that with lots of light higher ISO shots look better than they would with less light.
 
The23rdman said:
It's true and that's why DPReviews high iso studio tests are useless. I'm not talking about using uber high iso, but on a decent body 400 or so will look just great, and its possible to get away with higher.
Click to expand...

Indeed the DPR test shots or at least some of the high ISO test shots I've looked at are quite misleading. I've looked at some test shots and I've thought "WoW" but then I check the shutter speed and reasise that not all is as it seems and indeed my own lowly G1 which struggles at 3200 produces images at 3200 that look quite good when the shutter speed matches those of the DPR test images.

I do agree with you about being able to up the ISO if that's what you want to do and indeed when going even further than you suggest it may well give you, or me :D the look you/me are looking for.
 
HoppyUK said:
Not quite, you have 0.14ft of DoF, which is 1.7in or a bit over 4cm.

Yes, that's not a lot and will make things tricky even if the distance changes only slightly - remember that's both subject and/or camera moving.

Do some tests at f/8, f/11, and f/16 - see what you get. But you've reduced DoF a lot there by zooming in for a tight head & shoulders of a small lad.
Click to expand...

I did use the maximum zoom for those settings so have just done it again using the minimum, which nows offers nearly two foot of DoF, thinking i need to be shooting more around the 70-100 range, which sort of defeats the idea of getting the larger lens to allow for close ups, i possibly would have been better with a prime lens.

Am i right in thinking then, that if i meter everything at F8 and start shooting at 70mm, then say change to 100mm that the f8 changes, is there a way to work this out? how is this practical in a studio? if a child is moving back and forwards then i am always going to be changing the zoom thus changing the f stop.
 
HoppyUK said:
Not quite, you have 0.14ft of DoF, which is 1.7in or a bit over 4cm.

Yes, that's not a lot and will make things tricky even if the distance changes only slightly - remember that's both subject and/or camera moving.

Do some tests at f/8, f/11, and f/16 - see what you get. But you've reduced DoF a lot there by zooming in for a tight head & shoulders of a small lad.
Click to expand...

Okay done some test shots so first set are F16 and shot at 70mm, 100mm and 200mm
 
The23rdman said:
What body are you using? Up the ISO a bit to get some more leeway. Using lights allows you to get away with higher ISO than natural light.
Click to expand...

Sony A550, would upping the iso make that much difference in this situation?
 
stupar said:
I use a Canon 70-200mm F4 on a 5D2 for my studio portraits of kids.
If its any assistance to you when I do close ups (head/shoulders) shots I can get away with 1/125 at F10 - ISO 100 and thats with the Lencarta smartflash on full power.
When doing the close ups I try not to venture over 135mm (sometimes easier said than done)
Click to expand...

do you re meter when you change to 135mm?
 
Carlo, with depth of field, there's an almost exact reciprocal relationship between focal length and distance. In other words, if you shoot from 2m with a 100mm lens, then move back and shoot again from 4m with 200mm, DoF will be the same at the same f/number.

To get the DoF you need, select the lens aperture necessary from your experiments. Then adjust flash power and/or raise the ISO for correct exposure.
 
Sorry it's a bit late and trying to read up on where I am going wrong.

So the tests shots are pointless? With regards to my issue?

I did also check and I have OS set to on, I am using single shot AF and using spot AF.

I also tried the rear focus button and half pressing the shoot button and could see a difference
 
I use a multitude of lens but my general is the equivelant to a 80mm on a full frame most of the time, reason being is that with 18mp I can crop them if I so wish anyway and still print large for the most part and when visiting peoples homes often they are not quite as blessed for space as we are back at home with 16 feet worth of room so the short range can be usefull.

I usually use iso 400 with a sync of around 200 - 250th and f8 or so as often shooting more than 1 person at the moment
 
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