Camera shake even with strobes in studio?

[terence_patrick]

[attachment=13535:eye_detail.jpg]

Canon 5DMk2
Canon 85mm 1.8 @ f/8
1/125th shutter / 100iso
Profoto Pro 7A strobe, Pocket Wizard sync

The above 100% detail crop of a model's eye shows signs of very subtle camera shake, which is surprising to me considering this was shot in studio with a Profoto 7A strobe kit with magnum reflector. The shutter speed seems like it should be fast enough, although in reality, it shouldn't matter that much since I'm using strobe and there was no ambient light.

Anyone else experience this? Is there something I'm doing wrong or can do differently to fix the problem outside of using a tripod?

[dwdallam]

[attachment=13535:eye_detail.jpg]

Canon 5DMk2
Canon 85mm 1.8 @ f/8
1/125th shutter / 100iso
Profoto Pro 7A strobe, Pocket Wizard sync

The above 100% detail crop of a model's eye shows signs of very subtle camera shake, which is surprising to me considering this was shot in studio with a Profoto 7A strobe kit with magnum reflector. The shutter speed seems like it should be fast enough, although in reality, it shouldn't matter that much since I'm using strobe and there was no ambient light.

Anyone else experience this? Is there something I'm doing wrong or can do differently to fix the problem outside of using a tripod?

Why do you think it's camera shake?

[Boris_Epix]

I really don't think that this has anything to do with camera shake. You should be able to shoot the 5D at 1/200sec x-sync (however I got slight dark edge sometimes when shooting the old 5D so I tended to shoot it at 1/160). I have no idea why my 1Ds MK3 works well x-syncing at 1/250 sec but obviously the shutter is quite different.

THe 85 1.8 used to be a stellar portrait lens with the original 1Ds or film. But I found that at least my copy was not able to cope with the 1D MK2 and 1Ds MK2. I got purple fringing and softness that was not acceptable to me nor my customers. Now as the 5D MK2 and 1Ds MK3 have even smaller pixels the effect would be even more prominent. So I would guess that your lens is a bit challenged to resolve and maybe you have a bit of back/frontfocussing.

And hell... Canon files are soft and highlights/reflections often mushy. AA-filter and noise reduction at work.

If I was you I'd try to use a different L series prime lens and check out if that helps.

[terence_patrick]

My only guess as to why it's camera shake is because it's not consistently showing up throughout all the images. It's more of a pixel-peeping flaw since it's hard to see when zoomed out, but was just trying to understand what it was so I could correct anything I'm doing wrong in the future.

I had read something Michael wrote once about how any flaw in lenses or holding technique get magnified with the increased resolution of newer DSLR sensors, thus I thought the problem might be related.

[dwdallam]

I really don't think that this has anything to do with camera shake. You should be able to shoot the 5D at 1/200sec x-sync (however I got slight dark edge sometimes when shooting the old 5D so I tended to shoot it at 1/160). I have no idea why my 1Ds MK3 works well x-syncing at 1/250 sec but obviously the shutter is quite different.

THe 85 1.8 used to be a stellar portrait lens with the original 1Ds or film. But I found that at least my copy was not able to cope with the 1D MK2 and 1Ds MK2. I got purple fringing and softness that was not acceptable to me nor my customers. Now as the 5D MK2 and 1Ds MK3 have even smaller pixels the effect would be even more prominent. So I would guess that your lens is a bit challenged to resolve and maybe you have a bit of back/frontfocussing.

And hell... Canon files are soft and highlights/reflections often mushy. AA-filter and noise reduction at work.

If I was you I'd try to use a different L series prime lens and check out if that helps.

If I remember correctly, at F8 on that lens you don't get the front back focus problem. It's only at about f2 or larger.

I would take that lens and use the same settings, but shoot it on a tripod aimed at a ruler and see what you get.

[dwdallam]

My only guess as to why it's camera shake is because it's not consistently showing up throughout all the images. It's more of a pixel-peeping flaw since it's hard to see when zoomed out, but was just trying to understand what it was so I could correct anything I'm doing wrong in the future.

I had read something Michael wrote once about how any flaw in lenses or holding technique get magnified with the increased resolution of newer DSLR sensors, thus I thought the problem might be related.

You are using a single focus point in the view finder, right? Make sure that focus lock expansion is off also.

[Imaginara]

and a note on the 5D and sync. The 5D will sync at 1/200 with cable, but most radio slaves will require slower speeds. I sync pocketwizards at 1/160 on the 5D and 1/200 on the 50D.

[jjlphoto]

Here's what a 1Ds with the Contax 85/1.4-N can do with strobes, f8 @ 1/125 sec, using one-shot AF with one of the off-center focus points selected:
(Image on left is the full uncropped image.)
Processed in PhaseOne CO v3.7.8 with some capture sharpening applied, and some final output sharpening with Photoshop's USM.

(Sure, mine was fairly still, and I do not know if your model was really flying around or not, but your's does not really look like camera/subject movement blur.)

[MichaelAlanBielat]

From what I remember from the 85mm f/1.8 was that it has a pretty far minimum focusing distance of (2.8'). Did you definitely acquire focus on the eye? Were you in too close for that shot?

What was your AF settings? Do you have it enabled that you can only take a shot when focus is acquired or do you have it where it takes a shot any time your press the shutter?

That looks like you were working just a pinch too tight but I may be wrong... I had that same lens and the AF just died on me one day without rhyme or reason. Maybe yours is experiencing some of the same issues and the AF died right before time of capture... That focus lock expansion got me a bunch of times too when I had my Mark III...

Say I shot a bride from the side, the contrast over her eye may have not been enough for the camera to think it is a good focus point so it would use a surrounding focus point or two and "assist" with the AF point... Unfortunately that assisting meant that her ear and earring were tack sharp!

Disable that setting asap. I can imagine that is only good for real dark situations or landscapes if any...

[terence_patrick]

From what I remember from the 85mm f/1.8 was that it has a pretty far minimum focusing distance of (2.8'). Did you definitely acquire focus on the eye? Were you in too close for that shot?

What was your AF settings? Do you have it enabled that you can only take a shot when focus is acquired or do you have it where it takes a shot any time your press the shutter?

That looks like you were working just a pinch too tight but I may be wrong... I had that same lens and the AF just died on me one day without rhyme or reason. Maybe yours is experiencing some of the same issues and the AF died right before time of capture... That focus lock expansion got me a bunch of times too when I had my Mark III...

Say I shot a bride from the side, the contrast over her eye may have not been enough for the camera to think it is a good focus point so it would use a surrounding focus point or two and "assist" with the AF point... Unfortunately that assisting meant that her ear and earring were tack sharp!

Disable that setting asap. I can imagine that is only good for real dark situations or landscapes if any...

I'm probably 5ft from the model and I used the center focus point on single shot. The entire image has that micro-blur look, as if it was mirror bounce or something. Other images are sharp and in focus, so my guess is it's me. I'll attempt a few shots on a tripod next time out just to see.

[Jonathan Wienke]

It's not camera shake or any other kind of motion blur, you simply missed focus. If it was mirror slap or whatever causing the problem, the blur would be asymmetrical--e.g. greater along the vertical axis than the horizontal axis, or vice versa. Your image is simply soft, indicating a slight misfocus. You mentioned using only the center focus point; you might want to look at http://www.visual-vacations.com/Photograph...mpose_sucks.htm for an explanation why this is often a very bad idea, especially in a situation like yours.

Also, when DOF is measured in inches or fractions thereof, any slight movement of the subject or photographer between focus lock and shutter release can ruin focus, even if the autofocus is perfectly calibrated. Your non-use of a tripod makes this more likely.

[Rob C]

It's not camera shake or any other kind of motion blur, you simply missed focus. If it was mirror slap or whatever causing the problem, the blur would be asymmetrical--e.g. greater along the vertical axis than the horizontal axis, or vice versa. Your image is simply soft, indicating a slight misfocus. You mentioned using only the center focus point; you might want to look at http://www.visual-vacations.com/Photograph...mpose_sucks.htm for an explanation why this is often a very bad idea, especially in a situation like yours.

Also, when DOF is measured in inches or fractions thereof, any slight movement of the subject or photographer between focus lock and shutter release can ruin focus, even if the autofocus is perfectly calibrated. Your non-use of a tripod makes this more likely.

Thanks for the link, Jonathan. I have just been through this argument with another photographer and have tried to make the same point, including the brick wall, but by trying to get him to think of the situation as one where a T-square is being employed as an example. In other words. if the camera is placed at the base of the stem, aiming straight up the stem to the fixed cross-piece at the top, and focus made at that distance, then the line of the cross-piece, projected to both sides, describes the line of sharp focus parallel to the film/sensor plane. Then, if you rotate the T-square about the base of the stem (where the camera would be) to re-compose, that extended line of sharp focus is moved into an entirely different zone. It is difficult for some folks to realise that a distance of six feet is not always six feet!

The link has made it much easier to see the effect in a real situation - so thanks again - I shall forward it.

Rob C

[Jonathan Wienke]

The link has made it much easier to see the effect in a real situation - so thanks again - I shall forward it.

Rob C

You're very welcome. For some reason that article has become one of my more famous (or should I say infamous) web articles. Perhaps it's the catchy title?

[dwdallam]

It's not camera shake or any other kind of motion blur, you simply missed focus. If it was mirror slap or whatever causing the problem, the blur would be asymmetrical--e.g. greater along the vertical axis than the horizontal axis, or vice versa. Your image is simply soft, indicating a slight misfocus. You mentioned using only the center focus point; you might want to look at http://www.visual-vacations.com/Photograph...mpose_sucks.htm for an explanation why this is often a very bad idea, especially in a situation like yours.

Also, when DOF is measured in inches or fractions thereof, any slight movement of the subject or photographer between focus lock and shutter release can ruin focus, even if the autofocus is perfectly calibrated. Your non-use of a tripod makes this more likely.

Jonathan, that was a really good essay. It is interesting because as I have progressed as a photography and had these same problems, I came to the conclusion, after understanding DoF and f stops lens length and etc, to aim just in front of what ever you want sharp, unless as you state you are further away and it doesn't matter. It's also a rule of thumb to aim 1/3 of the way into the subject, when talking landscapes, to make sure the entire image is as sharp as possible--w/o actually measuring it off! I apply the same theory, depending on the situation, to portraits. Sometimes I may aim at the bridge of the nose, for example.

Thanks a lot.
PS--Fun to read too. (Fart in a tornado)

[dwdallam]

Thanks for the link, Jonathan. I have just been through this argument with another photographer and have tried to make the same point, including the brick wall, but by trying to get him to think of the situation as one where a T-square is being employed as an example. In other words. if the camera is placed at the base of the stem, aiming straight up the stem to the fixed cross-piece at the top, and focus made at that distance, then the line of the cross-piece, projected to both sides, describes the line of sharp focus parallel to the film/sensor plane. Then, if you rotate the T-square about the base of the stem (where the camera would be) to re-compose, that extended line of sharp focus is moved into an entirely different zone. It is difficult for some folks to realise that a distance of six feet is not always six feet!

The link has made it much easier to see the effect in a real situation - so thanks again - I shall forward it.

Rob C

I'm glad that was an easy concept for me to grasp. Seems intuitive. My post on camera movement in radial axis and speed was more difficult. I still don't quit get it.

[bgos]

I often shoot people in the studio close up with a 100mm lens, and I get serious motion blur every once in a while. I have no experience with profoto, but use dynalites and calumet strobes, and depending on the setting, I think the flash duration can be quite long. F.e. I tried to stop the motion of falling salt or pouring water, and it was almost impossible to stop. On the other hand, when I use on camera flash lights, these units have much shorter flash durations, and it is much easier to stop motion with them. So I don't think its unusual to get motion blur with studio strobes every once in a while. In regards to the focus not being right on, that's of course possible to, although I think at f8 and 85mm you have more than a few inches of focus depending on the subject distance of cause.

Bert

[dwdallam]

I often shoot people in the studio close up with a 100mm lens, and I get serious motion blur every once in a while. I have no experience with profoto, but use dynalites and calumet strobes, and depending on the setting, I think the flash duration can be quite long. F.e. I tried to stop the motion of falling salt or pouring water, and it was almost impossible to stop. On the other hand, when I use on camera flash lights, these units have much shorter flash durations, and it is much easier to stop motion with them. So I don't think its unusual to get motion blur with studio strobes every once in a while. In regards to the focus not being right on, that's of course possible to, although I think at f8 and 85mm you have more than a few inches of focus depending on the subject distance of cause.

Bert

Plus you can use High Speed Synch and use 1/8000 shutter speeds if you want. That should freeze it.

[Ben Rubinstein]

What is the flash duration of your strobes? Unlike speedlights the duration of a strobe can be far longer. I do get a frame like that every now and again, zero ambient light and streaked when shot with strobes. I guess I sometimes am shooting fast enough that I'm getting blur even with the 1/1000 duration of my strobes.

As for the focus recompose thing. If you focus up and recompose down you will get into trouble. Doing the opposite is far less of a problem. Think of the way DOF works and it makes sense. I personally focus recompose my 85 1.8 wide open pretty close up and have far less problems (read little to no) compared to using the 5D's useless off center focus points which can't begin to cope with that little DOF.

[dwdallam]

This is one of the reasons I like shooting with my 70-200 at 200 when I have the space.