Missing something obvious.... portrait lighting...

Folks -

 

Thanks in advance for your help/pity/advice/tips/reminders...

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I shot a colleague and his lovely wife yesterday up in my home studio, and had

a problem re-occur that I hadn't seen in awhile, and I'm looking for help to

diagnose it. I'll try to give all the stats up front, rather than forgetting

some critical piece of data like I normally do when I post here...

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5D body, 85mm 1.8, 1/200th, f/16, 400iso; both shots.

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3-light setup, high-key; 2 @ 300ws on backdrop, cross-lit. 1 main light for

subjects; 175ws through 5ft. octodome. Shot on sync cord.

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The problem, as I see it, is a dark banding at the right of the first shot and

bottom of the second. That it moves relative to orientation of camera says to

me it's not my lighting, but - likely - my shutter (I've seen questions of this

sort before posted, where the shooter is "seeing" the shutter/blades because

the speed/sync is off). Problem being, I thought I had the sync speed (1/200

for the 5D) all set, etc., etc. - thus, I hope someone out on the boards has a

helpful hint or "DUH" comment for me that can help me finish these shots off.

Shooting JTL monolights; is there a variable on that end that I'm missing? <p>

I'm pleased, overall, and it was a helluva lot of fun to do the shoot.

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Unedited pics, other than to resize for posting.

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<a href="http://www.photo.net/photo/5676775"> Picture 1 </a>

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<a href="http://www.photo.net/photo/5676771"> Picture 2 </a>

 

Many thanks for those of you who reply.

-Mike

Open your aperture up, to f/11 or wider then try it and see if its still there!

 

Ken.

I think it is both your light and your f stop. I agree, try f/11 but you might also need more

than a single mono which is what it looks like you used? A softbox up high, camera right,

may help.

Page 102 of your manual: the 5D syncs at 1/125 sec or slower with large studio flash. 1/200 is with Canon dedicated flash units. I use 1/160 with studio strobes with no problem. At 1/200 I've seen some shadowing from time to time.

Dave -

 

Thank you - that sounds like it's "IT."

 

I may have a profound misunderstanding of "things," but how/why would a difference between f/16 and f/11 account for heavy shading/lighting on only *one* side of a frame? There's nothing I know about aperture that I can reconcile with the shadow/banding on the pictures as shot. Granted, f/11 would brighten things overall, but that simply can't be what's responsible for the banding....... right?

 

Am I wrong in saying that any change to aperture would affect the *entire* picture, *every* time?

 

-Mike

Hi Mike, At first I thought it was just light fall-off when I looked at the first shot but on the second one it appears you have things pretty well lit. I'm looking at the examples on a laptop though so I may not be seeing things as well as I should.

 

I wouldn't *think* it would be the 1/200th shutter speed but I could be wrong. If so, you'll want to slow it down a bit. I've certainly used 1/200th quite a bit with my Canon cameras and had no problems.

 

I was just curious about your settings in general. While the 5D has great high ISO performance I was wondering why you didn't choose, say ISO 100 and meter your lights for something around f/8-ish. I suspect, as suggested above, it's possible the f/16 aperture could be the culprit.

 

It should be easy to test if you can find a willing "victim" to sit for a few minutes to fire off a few test shots using a bit more wide-open aperture, which in turn will make your lights work a little less hard and might give faster re-cycle times. It would also allow you to test the slower shutter theory as well as lowering your ISO if you want to try that route, purely for noise reasons. Good luck!

Mike!

 

Not necessarily, all it takes is for your sensor to be off set a fraction to have a slight effect to just one side instead of an even overall effect, in todays manufacturing, precision has went out the window in favor of cheap labor and faster production!

Lets put this another way, starting from the front of the lens all the way to the sensor, there are enough areas that if they don't line up perfectly, could cause light fall off to just one side, this has been noted on many camera/lens reviews at tight f stops!

Ken may be right - I'm certainly no "zen lighting guru" but at f/16 the *duration* of your flash must last a pretty long time to properly expose your subject; in other words the flash needs to "last a long time" and it may be falling off a little prematurely. If you can crank your light(s) back a bit, and compensate by opening up your aperture, it might help. Of course... I could be wrong! ;-)

It's probably a sync issue. You may be approaching the limit of the camera/strobe sync and therefore you begin to see the darkening caused by the shutter.

 

Try using 1/60s for starter and see what happens. Then, work your way up if necessary. Usually, in the studio, a speed of 1/60s is fine because there is NO available light to worry about. Also, there is no need to use 400 ISO in a studio shot such as the one you posted.

Clarification!

 

I didn't mean light fall off but actually vignetting of the aperture blades, less light reaching one side of the sensor due to too tight of an aperture, and without things aligning just perfectly, can cause this effect!

You know!

 

After looking at your posted photos again, This might be a combination of both a too tight of an aperture and to fast of a shutter speed, I first started with aperture because of the softness of the darker area, as usually to fast of a shutter produces a very black edge, and as Giampi said, why use such a high ISO for strobe lighting?

I'm not totally convinced that it is a shutter problem. When I have seen that, it is much more pronounced than this. It certainly has nothing to do with aperture setting. A series of tests will give you the correct answer. Simply shoot on your white bkgd, no model needed.

 

As others have said, set your ISO at 100, there's simply no need to go higher for this type of shot. Get aperture down to f:8 or 11 max. Set shutter at 1/125 max. You're overpowering all ambient anyway, so why make it higher. The white background should be exposed 1 stop brighter than the subject for high-key. You'll have more problems with flare on the edge of their faces/bodies leaving it the way it is.

 

Aside from that, my personal taste would be a much closer shot if you're using white, or dress them in light clothes, or use a darker background and put the emphasis on the people, not the bright areas.

 

Doug

Much obliged for all the input, folks - Doug, thanks for your other comments at the end of your post; I sincerely appreciate the additional feedback.

 

Once again, P.net proves well worth the subscriber costs..... !

 

-Mike

Mike,....Looks a bit like a shadow from a lens hood. You can shoot a 1/200 on the 5D with strobes and get partial frame exposure but this is not what it looks like when you do.

Mike, There is no good reason to shoot at the max sync speed in a studio situation, 1/60 -

1/125 is good, as you can control the ambient light to a low level. Also ISO 400 is a waste

and a chance for noise in the image should they want more than a small print, ISO 100 is

best. Also, watch for wrinkles in the clothes and make them as smooth as possible.

The light should be directed towards the points of primary interest, in this case, their faces

and her tummy. If the problem is not any of the previously suggested ideas, shoot a bit

wider and crop the image later. Paul

What's the sync speed of the 5D? Are you too high? lower to 1/125 or so and retry.