topic Re: Exposure Bracketing Issue in EOS DSLR & Mirrorless Cameras

EOS R6 Mark II Exposure bracketing changes aperture in M mode

Ovacheerdad — Wed, 04 Mar 2026 13:13:25 GMT

Question for those that use AEB. So I was watching some videos about exposure bracketing. Camera set to Man. ISO 100. and F/2.8. When I do a 3 shot stack it changes the aperture value to change the exposure. But when I run the same settings in AV mode, it keeps the aperture constant and actually changes the exposure. All the videos I'm watching online show that while in M mode, it does not change the aperture. Do I have something set wrong in my camera?

Re: Exposure Bracketing Issue

shadowsports — Mon, 02 Mar 2026 21:54:22 GMT

This is on your R6 Mark II right?

https://cam.start.canon/en/C012/manual/html/UG-03_CustomShooting_0050.html

In M mode you choose Shutter, Aperture and ISO

https://cam.start.canon/en/C012/manual/html/UG-03_CustomShooting_0060.html

If you're using ISO Auto then you can adjust exposure compensation.

Re: Exposure Bracketing Issue

Ovacheerdad — Mon, 02 Mar 2026 21:54:26 GMT

On the R6Mii yes.

Re: Exposure Bracketing Issue

shadowsports — Mon, 02 Mar 2026 22:35:47 GMT

Greetings,

I'm sorry you're using AEB.

Three consecutive shots so you're questioning why the exposure is changing between the three shots? In Av vs M.

The whole purpose of AEB is to give you three shots one underexposed one correctly exposed and one overexposed.

if you don't want your aperture to change you have to disable ISO Auto.

This should keep your aperture from changing after metering.

Re: Exposure Bracketing Issue

Ovacheerdad — Mon, 02 Mar 2026 22:44:14 GMT

Just tried changing that setting. Still changes the aperture. Ill try and take a video.

Re: Exposure Bracketing Issue

Ovacheerdad — Mon, 02 Mar 2026 23:13:52 GMT

Here is what it is doing. https://youtube.com/shorts/dZSetALz94M?si=O9uADYmT5xy31qmJ

Re: Exposure Bracketing Issue

stevet1 — Tue, 03 Mar 2026 02:11:37 GMT

Ovacheerdad,

I have a T8i, and just experimented with this.

If I put my camera in Manual Mode with a fixed ISO, and set an auto exposure bracket of three shots, my camera will automatically change the shutter speed.

If I use Av mode, it will keep the aperture and change the shutter speed.

If I use TV mode, it will keep the shutter speed and change the aperture.

Manual Mode surprised me. I would have expected the camera to refuse to make any adjustments.

While my camera is adjusting the shutter speed , maybe yours is adjusting the aperture. It might not be a flaw at all.

BTW, my camera did this regardless of whether I had Safety Switch disabled or not. The AEB must override the feature somehow.

Steve Thomas

Re: Exposure Bracketing Issue

Mack023 — Tue, 03 Mar 2026 06:58:56 GMT

I ran into this before! In Manual mode, the camera usually defaults to changing whatever you aren't 'locking' down. If you want the aperture to stay still for your stack, try setting your ISO to a fixed value (not Auto) and then check your AEB settings. Usually, if ISO and Aperture are fixed, the camera is forced to use shutter speed to bracket the shots.

Re: Exposure Bracketing Issue

Ovacheerdad — Tue, 03 Mar 2026 10:03:41 GMT

It is set at ISO 100. It still does it.

Re: Exposure Bracketing Issue

Ovacheerdad — Tue, 03 Mar 2026 10:43:22 GMT

After doing some digging a lot of digging actually, I'm fairly certain i found the answer in an old post from 2017. (SEE BELOW). I am at work and will try this as soon as i get home but I'm sure this will fix it. Thanks everyone for the input and trying to help.

Re: Exposure Bracketing Issue

Waddizzle — Tue, 03 Mar 2026 10:42:55 GMT

@Ovacheerdad wrote:

Here is what it is doing. https://youtube.com/shorts/dZSetALz94M?si=O9uADYmT5xy31qmJ

I apologize. I did not see the aperture vary in M model. If you could playback the images, then I could see the actual exposure settings.