EOS 6D After adjusting my aperture, the first photo I take is still at the previous aperture.

[jmunzial]

I am shooting with a Canon EOS 6D and 24-105mm lens.

I've been expereiecning a problem during product photography where my first shot will be shot at F7.1-F11. Then, I adjust to F13 and the next shot still appears to be shot at F7.1-F11 (whatever F stop I chose), as if there is faulty communication between the camera and lens.

This started yesterday where the next shot after I adjusted my camera to F13 was actually the opposite. It was darker, as if I shot it at F16-F18. I switched my lens, but then started experiencing the problem mentioned above. I changed the body thinking that it was the contacts on the body, but the same problem persisted, even after wiping down the contacts.

I have now tried 2 lenses & 2 bodies and I'm having the same issue. The next image after adjusting my aperture is not shooting at the aperture I've adjusted it to.

I know it's a probelm with my camera and not my lights because it specifically happens after adjusting the aperture. Is there anything else I could try? Does anyone know what this problem specifically is so I can get it repaired, if neccessary?

[Ray-uk]

This doesn't make much sense if it happens with different lenses and bodies, it can only be the way you have the cameras set up.

Try disabling "auto lighting optimizer", "auto ISO" and "highlight tone priority".

[jmunzial]

All 3 are disabled, as we are shooting an Manuel mode. I changed the body again & it hasn't happened. Perhaps I just had two bodies with faulty connections.

[cicopo]

Are you adjusting your shutter speed to match the aperture changes? You need a longer SS for smaller apertures & faster SS for larger apertures.

[jmunzial]

Uh, thanks for the photo 101 lesson, cicopo! I think you missed the point of my question entirely, and maybe that was my fault.

No, I'm intentially adjusting my aperture to capture darker interiors of my products with a constant SS of 1/125. 

[Waddizzle]

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@jmunzial wrote:

All 3 are disabled, as we are shooting an Manuel mode. I changed the body again & it hasn't happened. Perhaps I just had two bodies with faulty connections.

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Are you using any strobes or flash?  If you are in Manual shooting mode, then nothing should automatically change, not even ISO.  If you press the [Q] button, does it show "M" for Manual shooting mode?

[mehdi]

Canon cameras in particular do not calculate aperture in the same way that cameras from other brands do. Specifically, when you shoot at high magnifications like 1:1, the Canon cameras will read your aperture value incorrectly. It might say f/11, when everything about the photo (diffraction, depth of field, and exposure included) acts as if you’re shooting at f/22.

That is because aperture, on any lens, starts to do unexpected things at such high magnifications. In short, when your aperture is physically one size, it acts like another. Nikon, Sony, and other manufacturers all tell you the “functionally correct” aperture (f/22 in this case), while Canon does not. So, you need to keep that in mind when you shoot Canon cameras. This is far from an impossible drawback to overcome, but it is important to know about. The more frequently you change magnifications, the more of a problem this is.