Unexpected lighting/shadow effect in studio sessions.

Hi all,

I'm really just starting out with portrait photography and have done three sessions at a studio.

In two of the sessions I have noticed a graduated grey edge that appears on the bottom section of my frame, in this image it is on the left. You should spot it pretty easily. It occurs on most, but not all images.

I'm shooting with a 5D MkIII, with an off camera trigger at ISO 100, f/8 at about 1/150s to 1/250s. I recall having the same issues with shooting on my 7D too.

External Speedlite Control is set to:

E-TTL meter Evaluative
Flash Sync Speed Auto

Can anyone suggest what the cause and remedy is so I do not get this phenomenon again? It's reasonably easy to remedy in PP, but the less work we have to do the better.

I'm thinking it's either the shutter speed of the image sensor is catching the mirror movement or something.

EXIF Data attached

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Max flash sync speed for 5D is 1/200. If you shoot at 1/250, you'll see that darkened bar. Increase the shutter to 1/500 and you'll see it's a lot bigger. Max flash sync speed basically means that is the fastest shutter speed you can use before seeing that dark bar. 1/200 SHOULD NOT have the bar, but sometimes it has it but very faint... so some studio photographers stick to 1/160.

Fashion could be correct....that you are catching part of the shutter. You mention that you are shooting 150 to 250. Are you getting this at the slower shutter speeds as well?

I have a 500D and shoot a 430EXll off camera triggered with Radiopoppers. I can shoot at a 250th and below I don't get this effect. I would think the 5D should be able to as well.

What kind of flash and trigger are you using?

the reason it moved from the bottom to the side is because you rotated the camera to shoot in portrait format for this shot. I agree with the above responses: synch speed.

def synch speed

nes_matt wrote in post #15875083
the reason it moved from the bottom to the side is because you rotated the camera to shoot in portrait format for this shot. I agree with the above responses: synch speed.

That's good information for others who may not have thought of that one.

Thanks for including it where I had omitted to make that observation clear.

saea501 wrote in post #15874963
Fashion could be correct....that you are catching part of the shutter. You mention that you are shooting 150 to 250. Are you getting this at the slower shutter speeds as well?

I have a 500D and shoot a 430EXll off camera triggered with Radiopoppers. I can shoot at a 250th and below I don't get this effect. I would think the 5D should be able to as well.

What kind of flash and trigger are you using?

Thanks for your input all.

Being narrowed to shooting at 1/160 will degrade image quality some at future shoots. Maybe I need to improve my technique?

I can find out. The remote triggers are supplied by the studio and have four dip switches (1,2,3,4) for coding flashed used on the set. I don't recall a branding.

Hmmm...how does shutter speed degrade image quality if you are doing portraits? I can see if you shoot 1/160 in faster moving objects that you may get blurry images. Please do share your information, thanks.

Here is one shot at 1/80...

Buckeye1 wrote in post #15875179
Hmmm...how does shutter speed degrade image quality if you are doing portraits? I can see if you shoot 1/160 in faster moving objects that you may get blurry images. Please do share your information, thanks.

Here is one shot at 1/80...

As indicated in an earlier post I have only shot in a studio a hand full of times so however I explain myself it will be pretty elementary to those who know better. Still I have an reasonable awareness of light an shutter speed.

Yes, moving subjects will introduce movement effects in the final image. Moving subjects/camera movement at low shutter speeds produces a softer image. Certainly a brighter light, such as a strobe can improve this lack of detail by introducing more light entering the lens and masks the sensor with a second exposure. We all know that there are really two or more exposures when using flash don't we ... the natural light (if any) plus that of the strobes.

Looking back at my post, definitively, I'm using the wrong term. Image quality, that being what is recorded by the sensor is not going to degrade. However the appreciation of the available sharpness and quality of the end product will considering there is movement either with the subject or camera.


We are moving away from the purpose of the original post.

wayne_eddy wrote in post #15875227
As indicated in an earlier post I have only shot in a studio a hand full of times so however I explain myself it will be pretty elementary to those who know better. Still I have an reasonable awareness of light an shutter speed.

Yes, moving subjects will introduce movement effects in the final image. Moving subjects/camera movement at low shutter speeds produces a softer image. Certainly a brighter light, such as a strobe can improve this lack of detail by introducing more light entering the lens and masks the sensor with a second exposure. We all know that there are really two or more exposures when using flash don't we ... the natural light (if any) plus that of the strobes.

Looking back at my post, definitively, I'm using the wrong term. Image quality, that being what is recorded by the sensor is not going to degrade. However the appreciation of the available sharpness and quality of the end product will considering there is movement either with the subject or camera.


We are moving away from the purpose of the original post.

I am a studio photographer and I ONLY shoot at 1/160 with strobes. Your logic is flawed. And I have thousands of tack sharp images to prove it.

wayne_eddy wrote in post #15875227
We are moving away from the purpose of the original post.

Didn't you ask this in your original post? "Can anyone suggest what the cause and remedy is so I do not get this phenomenon again?"

You've been around this site longer than I, but unless I'm reading something incorrectly, that's what people here are doing. Myself, I have even less experience than you so I'm interested in the answers as well.


Also, I thought I remembered you from another thread, and I went back and saw where you had offered this advice to someone who I believe had posted their first HDR image:

One day you will look back on the posts in this thread and be glad experienced people told you what they thought. Imagine if the thread went the way of many others and you had a string of "nice shots" which is common place on forums and doesn't motivate people to better. I'd prefer people tell me how it is.

I hope you get the information you're looking for.

Agree we're getting off the topic a little bit here. Let's just summarize everything and end it.

OP asked what the black bar is
Answer: sensor is catching the shutter as it's closing due to a fast shutter speed. Although Canon 5D's stated max sync speed is 1/200, it will still show a small amount of the bar, so 1/160 is recommended. Shutter leaves will always move up and down when camera is held horizontal, so bar shows up at the bottom. When held vertical, the leaves are now going side to side, so bar is on the side of the photo.

No, image quality isn't affected by shutter speed. However, it does minimize motion blur which results in a sharper image. If shooting studio and using strictly lights with no ambient lighting, you should ALWAYS shoot at your max shutter speed (1/160 for OP if he wants to avoid black bar). There's no reason to shoot 1/80 because the lighting will still look the same, but it just increases chances of motion blur the slower you go. Remember, shutter speed does not affect strobes... unless you go past sync speed.

When using radio triggers, the trigger introduces a slight delay.

Depending on how large that delay is, the flash might trig just after the shutter has started to close again, resulting in a black bar even when the camera shutter speed is within supported flash sync speed.

So if you get the bar at 1/200 but are okay at 1/160, then the triggers are most probably the cause of the issue.

CincyTriGuy wrote in post #15875562
I am a studio photographer and I ONLY shoot at 1/160 with strobes. Your logic is flawed. And I have thousands of tack sharp images to prove it.

Thank you for contributing.

Spats139 wrote in post #15875871

Didn't you ask this in your original post? "Can anyone suggest what the cause and remedy is so I do not get this phenomenon again?"

You've been around this site longer than I, but unless I'm reading something incorrectly, that's what people here are doing. Myself, I have even less experience than you so I'm interested in the answers as well.


Also, I thought I remembered you from another thread, and I went back and saw where you had offered this advice to someone who I believe had posted their first HDR image:

One day you will look back on the posts in this thread and be glad experienced people told you what they thought. Imagine if the thread went the way of many others and you had a string of "nice shots" which is common place on forums and doesn't motivate people to better. I'd prefer people tell me how it is.

I hope you get the information you're looking for.

Yes thanks I did.

You should have put the thread URL in there too so everyone could read it and make up their own mind. But I see you have chosen the bits you want to display.

Are you a journalist?