topic Re: R5 Mk II Shutter buttoner "AE lock (while button pressed)" in EOS DSLR & Mirrorless Cameras

EOS R5 Mk II Shutter buttoner "AE lock (while button pressed)"

pedz — Thu, 23 Apr 2026 11:59:21 GMT

I'm trying to slowly work up a bunch of notes on Canon cameras. I've mentioned this before in this forum. I've never really thought about it before but the shutter button on this camera and I think every Canon camera I've ever owned can be set to "AE lock (while button pressed)". On the R5 Mk II, this setting can only be put on the half press of the shutter button.

I didn't realize this but "metering" is active all the time. I set my camera to manual mode with auto ISO and as I pan around, the ISO is changing without me touching the shutter button. It doesn't matter how the half press of the shutter button is programmed. Without touching the shutter at all, the ISO changes as I pan around.

The "metering start" that the other possible options of the half press of the shutter button can be set to is actually not really true. Metering is started as soon as the camera comes out of sleep.

Just as the text says, when the half press of the shutter button is programed to "AE lock (while button pressed)", the AE is locked when the shutter is half pressed. In my test, the ISO is fixed while I pan around. With the other three possible settings, the ISO continues to change as I pan around while half pressing the shutter button. (Again... no surprised). The surprise to me is that metering is always active unless the camera is sleeping.

Re: R5 Mk II Shutter buttoner "AE lock (while button pressed)"

Waddizzle — Wed, 22 Apr 2026 18:48:52 GMT

“ I didn't realize this but "metering" is active all the time. I set my camera to manual mode with auto ISO and as I pan around, the ISO is changing without me touching the shutter button. “

Is “Preview AF” enabled? Pre capture?

Re: R5 Mk II Shutter buttoner "AE lock (while button pressed)"

pedz — Wed, 22 Apr 2026 19:16:10 GMT

Preview AF is off and I am in single shot mode of pre capture can't be on. Is it different for you?

Re: R5 Mk II Shutter buttoner "AE lock (while button pressed)"

Waddizzle — Wed, 22 Apr 2026 19:56:14 GMT

I am not by my camera.
What is your metering timer set to?

Re: R5 Mk II Shutter buttoner "AE lock (while button pressed)"

stevet1 — Wed, 22 Apr 2026 21:55:01 GMT

pedz,

In your post, you don't say if you have kept your focus lock on the half-press if the shutter button, or if you have switched to back button focus.

If you have kept it on the shutter, I can foresee one situation whee you might run into some difficulty. Let's say you want to do a silhouette. If you meter off the sky and lock you exposure, and keep your shutter half pressed, if you are in One-Shot focus mode your focus will still be on the sky and not on the subject in front of you as you recompose your shot.

If you are in Servo focus mode, the exposure will lock, but the camera will continue to re-focus as you swing your camera around.

I have a T8i, and I still left my AE lock on the * button. It will lock the exposure, but only hold that lock for about six seconds. I changed my focus to the AF-ON button, and if I hold that button down with my thumb, it will hold that focusing and metering lock as long as I keep that button pressed down. Pressing down on the Depth of Field Preview button will also hold that metering lock.

Steve Thomas

Re: R5 Mk II Shutter buttoner "AE lock (while button pressed)"

pedz — Wed, 22 Apr 2026 22:44:29 GMT

I might need to clarify a little. I touch the shutter button and this wake up the camera and starts an 8 second timer. During that time, without holding the shutter half way down, the exposure is changed as I pan the camera around. I can see the ISO numeric reading changing. After 8 seconds, the ISO reading switches to AUTO and it doesn't change after that until I touch a button.

My R7 appears to operate the same way.

Re: R5 Mk II Shutter buttoner "AE lock (while button pressed)"

pedz — Wed, 22 Apr 2026 22:48:58 GMT

I am not thinking about focusing nor really about taking photos. I am just exploring how the camera works. I set the shutter button to each of the four different possible settings and then tried to explore what the camera seemed to be doing with the button not pressed as well as half pressed.

Re: R5 Mk II Shutter buttoner "AE lock (while button pressed)"

Waddizzle — Wed, 22 Apr 2026 23:08:26 GMT

“ might need to clarify a little. I touch the shutter button and this wake up the camera and starts an 8 second timer. During that time, without holding the shutter half way down, the exposure is changed as I pan the camera around. I can see the ISO numeric reading changing. After 8 seconds, the ISO reading switches to AUTO and it doesn't change after that until I touch a button. “

That is normal behavior for when AF Start has been removed from the Shutter button.

” Preview AF is off and I am in single shot mode of pre capture can't be on. Is it different for you? “

BTW, single shot mode is a drive mode, not an auro focus mode. I assume you mean One Shot AF. One Shot AF locks exposure when it achieves a focus lock. Servo AF locks exposure when the Shutter is fired:

Re: R5 Mk II Shutter buttoner "AE lock (while button pressed)"

Waddizzle — Wed, 22 Apr 2026 23:14:08 GMT

One more thing, you cannot assign the same function to more than one control.

Re: R5 Mk II Shutter buttoner "AE lock (while button pressed)"

jrhoffman75 — Wed, 22 Apr 2026 23:34:56 GMT

@pedz wrote:

I might need to clarify a little. I touch the shutter button and this wake up the camera and starts an 8 second timer. During that time, without holding the shutter half way down, the exposure is changed as I pan the camera around. I can see the ISO numeric reading changing. After 8 seconds, the ISO reading switches to AUTO and it doesn't change after that until I touch a button.

My R7 appears to operate the same way.

That is correct. Once you start the timer the function controlled by the timer takes command until it times out.

Re: R5 Mk II Shutter buttoner "AE lock (while button pressed)"

pedz — Fri, 24 Apr 2026 01:02:54 GMT

I might misunderstand what you are saying but I just assigned AF Point Selection to my AF-On button and my AF Point selection button at the same time.

Re: R5 Mk II Shutter buttoner "AE lock (while button pressed)"

Waddizzle — Fri, 24 Apr 2026 10:35:36 GMT

“ I might misunderstand what you are saying but I just assigned AF Point Selection to my AF-On button and my AF Point selection button at the same time. “

I think you misunderstood me. Those two entirely different functions. They have different names.

You should not be able to assign AF Preview to both buttons, for example. That’s what I meant.

If you try, the first button should revert back to its defaulr, or something else entirely. You seemed to indicate that you were trying to assign AE LICK to two different controls.

Re: R5 Mk II Shutter buttoner "AE lock (while button pressed)"

pedz — Fri, 24 Apr 2026 12:54:03 GMT

Now I'm even more confused. The functions I am referring to are listed in "Functions available for customization" listed on this page. (You need to scroll down some). The function I assigned was "AF Point Selection" which is the third entry in the table. That is one function. I assigned that function to two buttons: the AF-On button and the AF Point Selection button -- buttons 17 and 18 as shown in the second diagram (of the back of the body) shown on this page. And... I don't know what you mean by the "AF Preview" function.

Re: R5 Mk II Shutter buttoner "AE lock (while button pressed)"

Waddizzle — Fri, 24 Apr 2026 14:02:11 GMT

“ Now I'm even more confused. “

Do you have a specific question? You are confusing me. Do not try to assign the same function to more than one control. That’s the rule.

Re: R5 Mk II Shutter buttoner "AE lock (while button pressed)"

pedz — Fri, 24 Apr 2026 14:19:13 GMT

But what you are saying is not true. That's my point. I have successfully done it.

Re: R5 Mk II Shutter buttoner "AE lock (while button pressed)"

jrhoffman75 — Fri, 24 Apr 2026 14:28:19 GMT

Yes it can be done. Has your original issue been addressed or do you want to re-state it.

Re: R5 Mk II Shutter buttoner "AE lock (while button pressed)"

pedz — Fri, 24 Apr 2026 14:36:25 GMT

I never had an issue. I was simply sharing what I have recently learned thinking it might help others.

Re: R5 Mk II Shutter buttoner "AE lock (while button pressed)"

jrhoffman75 — Fri, 24 Apr 2026 18:53:22 GMT

Maybe you want to check solved then.

Re: EOS R5 Mk II Shutter buttoner "AE lock (while button pressed)"

Waddizzle — Sat, 25 Apr 2026 01:18:50 GMT

“ But what you are saying is not true. That's my point. I have successfully done it. “

You have not successfully done anything. You are jumping to shallow conclusions.

The Shutter seems to be an exception. For example, the “AF Start” & “Metering Start” functions are on both the [Shutter] and [AF ON] controls by default.

I suggest that you try your test with two different controls other than the Shutter. You should not be able to assign the same function to two separate controls. If you can, then I would consider that to be a firmware issue.

Re: EOS R5 Mk II Shutter buttoner "AE lock (while button pressed)"

jrhoffman75 — Sat, 25 Apr 2026 01:39:15 GMT

@Waddizzle wrote:

“ But what you are saying is not true. That's my point. I have successfully done it. “

You have not successfully done anything. You are jumping to shallow conclusions.

The Shutter seems to be an exception. For example, the “AF Start” & “Metering Start” functions are on both the [Shutter] and [AF ON] controls by default.

I suggest that you try your test with two different controls other than the Shutter. You should not be able to assign the same function to two separate controls. If you can, then I would consider that to be a firmware issue.

Not sure why you say this. Triple back button focus that many wildlife/bird photographers use is a prime example.