Thick dark cloudy line, rare but in some indoor photos

[Westmittenphoto]

I'm a wedding and portrait photographer and have noticed in certian indoor locations I get these thick dark cloudy looking lines/ areas of in my photos. I'm wondering if there is a setting that is making this an issue, or the fact that I use the lens mount adapter and use my older L lenses and some sigma lenses, or something else. The photo below is not one that I would have kept anyway, but the issue i'm talking about is very visible right down the middle. Sometimes that dark area is off to the side, but its always about that big. If anyone has insite into this issue, please let me know! It is pretty rare, but it makes me nervous enough to debate getting rid of both of my EOS R's since weddings can't be reshot. I appreciate any help I can get. 

[Ray-uk]

Difficult to tell from that shot, could be a shutter issue. Were you using HSS flash or available artificial lighting?

[Westmittenphoto]

I was just using the ambient lighting in the room no flash or any other lighting set up. I have two EOS R's and both produced photos like this on and off in this room though out the night. 

[jrhoffman75]

Is that perhaps what flicker looks like from the LED bulbs? I've never experienced it so I don't know. 

[Ray-uk]

Could have been artificial light flicker, all mains lighting is flickering all the time but our eyes cannot see it, some modern LED mains bulbs flicker at a very fast fate which can cause odd photo problems. Has the R got a flicker detect setting in the menu, a lot of cameras now have it.

[BurnUnit]

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@Westmittenphoto wrote:

I was just using the ambient lighting in the room no flash or any other lighting set up. I have two EOS R's and both produced photos like this on and off in this room though out the night. 

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I've seen some string lights that look similar to the ones at the top of your photo. They tend to be LCD bulbs which have a flicker to them much like fluorescent lamps. If you can try shooting again under the same lighting conditions try dropping shutter speed step-by-step and see if things improve at 1/60, 1/30 or slower speeds.

[Waddizzle]

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@BurnUnit wrote:

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@Westmittenphoto wrote:

I was just using the ambient lighting in the room no flash or any other lighting set up. I have two EOS R's and both produced photos like this on and off in this room though out the night. 

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I've seen some string lights that look similar to the ones at the top of your photo. They tend to be LCD bulbs which have a flicker to them much like fluorescent lamps. If you can try shooting again under the same lighting conditions try dropping shutter speed step-by-step and see if things improve at 1/60, 1/30 or slower speeds.

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The EOS R bodies should have Flicker Detection.  I tend to think it is light flicker, too.  If the camer body lacks that feature, another solution is use a flash with a diffuser, or bounced off the ceiling.

[wq9nsc]

I agree with others that this is probably an artifact of light flicker and typical LED bulbs fed from the AC line are the worst because the response time to voltage change is basically instantaneous.  Traditional incandescent lighting has such a high thermal lag that flicker isn't an issue and other popular light sources that flicker aren't quite as responsive as LEDs so although they do cause flicker it is usually of a lesser magnitude.

The anti-flicker setting built into cameras will not work well with LED bulbs in many situations because the anti-flicker algorithm in the camera expects flicker to occur at a multiple of either 50 or 60 hertz which are the standard AC frequencies used in various parts of the world.  The simplest LED bulbs will flicker at a rate synchronized to the line frequency and anti-flicker will work but even some of the most basic LED bulbs are moving towards more efficient use of power.  More efficient drivers aren't locked to the line frequency and they will change as voltage and temperature changes, also many LED bulbs on a dimmer will also flicker in a pseudo random fashion not tied to the AC line frequency. 

It is common in many settings to have a mix of LED and HID (high intensity discharge lighting) such as a sports gym or outdoor stadium because the efficiency advantage for an LED array isn't nearly as large when large output is needed and the comparison is a high pressure sodium lamp instead of incandescent.  The problem is that if your camera is set to use anti-flicker, it may detect and "trigger" off the pseudo random LED flicker causing even worse artifacts than shooting with no flicker reduction.  Some high output LED arrays over drive the LEDs at a low duty cycle to get the best mix of cost versus output level but the problem for photographers is that in extreme cases there can be significant color shift as the over driven LED transistions from on into overload. 

Bottom line is that very few venues concern themselves with lighting for photography.  There basic requirements are initial cost and long-run cost (energy use, lifetime, and maintenance during lifetime).  Because of this methods like Waddizzle mentioned including flash will become necessary where it wasn't in the past. 

Rodger

[Westmittenphoto]

Thanks everyone, all great things to know!

[ebiggs1]

I like the idea of adding a bounce flash but on such a grossly underexposed picture I don't think any of us can say definitively.

It could be the bill of you ball cap or a hanging decoration that got in the way. A misaligned lens hood.