Because power consumption has always been a concern with mirrorless cameras, I've assigned the 'AF point' button (top right) to the 'Display Off' function for topside shots on my Canon R5 for years.

For some reason, however, I can't activate this function in my Nauticam housing.

And it's only this function that's affected!

If I assign the button to, for example, 'drive mode', I can activate that with the 'AF point' button - and this applies to all other buttons as well: 'Display Off' can't be activated.

Does anyone have any idea what could be causing this?

From what I understand, then, the button on the Nauticam housing works.

I don't have a Canon, but... check the EVF settings.

In Lumix cameras, there are settings where the EVF and the display can be set to activate exclusively. As soon as you bring your eye close to the EVF, the display turns off. There is a proximity sensor near the EVF. When you close the back of the housing, it's as if you were bringing your eye close to it.

Maybe there is some setting causing this mess.

Without the housing, try covering the EVF with a finger and using the button to see if it works.

Ciao

Hi Davide,

thanks for your reply!

I already tested that:

There are four different viewfinder/display options on the R5, but unfortunately 'display off' doesn't work with any of them.

On 6/7/2026 at 4:46 PM, waso said:

Because power consumption has always been a concern with mirrorless cameras, I've assigned the 'AF point' button (top right) to the 'Display Off' function for topside shots on my Canon R5 for years.

For some reason, however, I can't activate this function in my Nauticam housing.

And it's only this function that's affected!

If I assign the button to, for example, 'drive mode', I can activate that with the 'AF point' button - and this applies to all other buttons as well: 'Display Off' can't be activated.

Does anyone have any idea what could be causing this?

So you are saying pressing the AF point button outside the housing activates display off, but inside the housing it won't work, but other functions assigned to that button work inside the housing?

Maybe there is a eye detection function in the camera viewfinder and inside the housing it thinks there is an eye at the viewfinder and won't activate the function, because it thinks you are still using the viewfinder? You could test by covering the eye sensor to see if it stops activation outside the housing?

8 hours ago, Chris Ross said:

So you are saying pressing the AF point button outside the housing activates display off, but inside the housing it won't work, but other functions assigned to that button work inside the housing?

Exactly!

9 hours ago, Chris Ross said:

Maybe there is a eye detection function in the camera viewfinder and inside the housing it thinks there is an eye at the viewfinder and won't activate the function, because it thinks you are still using the viewfinder? You could test by covering the eye sensor to see if it stops activation outside the housing?

Yes, that seems to be the case, I just tested it.

It works with the R5II, by the way.

Hi Wahrmut,

I have the R5. Here is how I set it up for Viewfinder/Display.

1. Menu->Setup Menu (yellow wrench)->Screen/viewfinder display (3)->Screen

2. Menu->Custom Functions->Customize buttons(3)->Assign the * (AE Lock button) to 'Switch between VF/screen'.

I customized the * (AE Lock button) to toggle between screen and viewfinder, but you could choose another button instead.

Hello JayceeB,

I use the LCD/VF switch on top of my Nauticam housing to switch between the viewfinder and the display – this is very convenient because I don't have to go into the camera menu or assign a shortcut button.

However, I practically never use the display anyway...

My 'problem' is that I can't assign the 'display off' function to any button, as the R5 seems to detect that something is near the viewfinder. Perhaps you could try assigning the 'display off' function to a button on your camera.

I'm very curious to see if that might work for you.

I set the illumination button to 'display off'. It works with the camera out of housing, but in housing it does not work. I tested it in a Marelux housing. FYI, I have never mapped to this button or used this button via my housing before.

Next, I tried covering up the entire back of the camera to see if it was linked to the eye sensor in the Viewfinder. Using the camera illumination button worked fine.

I then started fiddling with the housing illumination button. Activating the housing button pushed a lever down that didn't even look close to where the button was on the camera. I wiggled the lever, and it actually rotated easily and was not even secured. I pulled the lever to the top, and it clicked into place. Tested again with the camera in housing, and it worked.

The camera lock button lever behaved the same way. Looks like both those levers were never positioned and locked in place. I never noticed because I had never used those housing buttons before.

Perhaps the Nauticam housing has the same lever design?

Photos showing the lever before and after I rotated the levers up in place.

I'll have to try to replicate that tomorrow (it's already quite late here in Germany 😴), but I'm just realizing that my nauticam case doesn't have a button for the display backlight.😐

Thanks for looking into this issue!

Since my Nauticam housing unfortunately doesn't have a button for the display illumination, I have to use a different button – which doesn't make any difference in principle.

What I've discovered is that the small optical sensor directly below the viewfinder is responsible for automatic detection. If this sensor is covered (in viewfinder mode!), 'display off' doesn't work.

I've found a workaround, albeit a bit cumbersome:

If I set the screen/viewfinder display to Auto2 and then switch the lever on the Nauticam housing to LCD, I can activate 'display off' because the optical sensor below the viewfinder seems to be deactivated.

Perhaps this setting prevented the optical sensor from being active for me.

1. Menu->Setup Menu (yellow wrench)->Screen/viewfinder display (3)->Screen