Dark vignette appearing on one side of pics taken with Canon R6 when using studio strobes

[Radison]

I'm having a problem with vignette/banding on one side of my pics when using studio strobes. At first I thought this might be caused by exceeding the shutter speed max resulting in banding from the curtain but the attached samples were all shot at 1/160 which is well within the 1/250 max for my Canon R6 when using studio strobes (Alien Bees). These were shot at 100ISO, 58mm, f6.3 using my Canon 24-70 f2.8 L lens. The strobes are set up either side of me at the same distance on the same power level

This seems to keep happening when I do studio shoots and I would really appreciate any thoughts on how to fix the issue. Thanks a lot!

Vignette is at the bottomVignette is on the leftVignette is on the left

[Waddizzle]

Light flicker?  How much ambient lighting is in the photos?  But, it is weird that it always seems to be in the same place, though.

[Radison]

Thank you for your input, I really appreciate it. It seems to occur each time I work with strobes in a studio. I don't notice the issue for outdoor shoots. In the studios I use they generally have some natural light from a skylight or windows which is consistent rather than flickering. Does that give you any ideas?

[ebiggs1]

"... it is weird that it always seems to be in the same place, though."

I gave that some thought, too. I am still leaning to the BG not being exactly perpendicular (or flat) to the camera. As you can notice in the last example the bottom edge of the BG isn't straight. It doesn't take much to cause a slight difference in lighting. The vignette is slight anyway so a simple task to correct in PS.

[Radison]

Yes, that's a great observation. I check other pics and they a more perpendicular and the vignette is still present. But I will definitely keep a look out for this in future.

[ebiggs1]

I just got through with a 100+ photo shoot on a green screen and saw similar situation. In my case it was to delete the BG so no biggie. PS took care of it for me.

[Radison]

I see. Ok, thank you. In my case I think I will need an alternative solution than replacing the background on hundreds of pics. Hopefully someone else will have other ideas we can both try. Fingers crossed!

[ebiggs1]

In my case I needed to replace the BG and use this one.

The student is removed from the BG and placed in this to make a 24"x36" poster on canvas.

I have done this for years so it has  become a simple set of procedures for me. I used a green screen but I do not recommend it. A neutral gray like yours is prefered. Also it was a fabric screen and I don't like that either because there is invariably variations in it. I was not at my own facility but you do what you have to do. That's a photographer's life isn't it?  🤔

[amfoto1]

It's quite possible the 1/160 shutter speed you are using is a little too fast. Try a little slower.

Most studio strobes fire slower than portable flash, so slower shutter speeds are necessary. It varies depending upon the particular strobes. With my Normans I can use 1/160 on cameras that sync flash at 1/200 and 1/180 on those that sync up to 1/250. However, that's no guarantee the same is true with your strobes. To me it looks like the 1/160 you're using is just a tiny bit too slow. Anyway, it's easy to try and see if 1/125 solves the problem.

***********

Alan Myers
San Jose, Calif., USA
"Walk softly and carry a big lens."
GEAR: 5DII, 7DII (x2), 7D(x2), EOS M5, some other cameras, various lenses & accessories
FLICKR