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Dear Blaster-34 ...

I am a Canon user and currently own the EOS R5... I too, have continued to struggle with the same question

Being the 'Geek' that I am, I decided to perform my own 'ad-hoc' test by doing the following...

1- Set my camera w/ my RF 100-500mm @ 500. setup in my residence office, point across the street
2- Tripod was a Mammer-Jammer $ 1,200/ Gitzo, carbon fiber, w/ a $ 350 Gembal head..
3- Set my shutter speed to 1/10 second, and using the display monitor on the back of the camera
4- I then 'focused' on an 'element' across the street @ 500mm and set AutoFocus 'Off'
5- At this point, I used the 'zoom' function of the camera to 'zoom' in 16x, to test this at extremes.

..... Yes, the above is effectively 8,000mm (500x16) but, after all, you want to see the results

With the above, after taking all 'hands-off' the equipment... one can see "NO movement" of the image.
..BUT, if you 'switch' "IS" on, and take 'hands-off' ... you will see distinct 'Image Drift' in the camera display

. Just saying... and that is only "MY TEST" for my purpose and consideration...
..The above are 'real life facts' and not just some 'theory' or 'guess' or unverified 3rd party information ???
...I do most of my work in landscapes... and after all, what can it hurt to turn off 'IS" if you are on a tripod??

As a result of the above, I have made the personal decision that when I use a tripod, me personally, I will turn off the "IS" as a matter of personal choice, and a 'extra measure' to guard against 'sensor drift'

I offer the above only as info... and to each his own...
...... I am not professing that is this the right way to do things or not the right way

Just information for consideration


Cheers
Goldstar46
George Veazey
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This topic comes up a lot. The CORRECT answer varies by camera brand and model! Stabilization systems are NOT standard. Is yours in the lens? In the body? In both? How many axes of movement are involved? Three? Five?

Some cameras automatically turn on stabilization when there is camera movement and turn it off when there is none. Others can't discern that, so they require the user to turn it off when the camera is on a tripod. Consult your full operations manual for the details. Older cameras are more likely to require your intervention to avoid movement CAUSED by the stabilizer(s).

There are many potential causes of vibration even when using a tripod which could benefit from the image stabilization of a lens and camera being on, including the movements of the shutter, wind moving the lens, your pressing the shutter button, etc However in the "early days" of image stabilization one could see that turning off this system would result in a sharper photo (I actually did some tests a number of years ago and saw this) when the unit was on a tripod. However with the newer image stabilization systems this is not very common.