Just as in the DPreview forum, I'm already reading some posts here about shutter shock, people talking about it as if it's a well-established issue with the M6ii camera, and even warning people off the camera as this being an established fact.
I've been shooting with the M6ii for well over two years now, and shoot nearly daily with 2 of the 3 M6ii bodies I now own. I do sometimes shoot mechanical shutter with the EF-M 11-22mm, EF-M 15-45, EF-M 18-55, EF-M 18-150, EF-M 55-200, EF-S 55-250 IS STM (with and without a 1.5x TC), and Sigma 150-600 (EF) Contemporary (with IS) zooms at shutter speeds as low as 1/100 to capture trains around sunset before switching to fast primes for night shooting.
I routinely zoom to the pixel level when processing images in DxO PhotoLab 6, I like to examine the pixel level sharpness when setting de-noise and sharpness for each image.
I have not seen this so-called shutter shock in my images with any of the three M6ii bodies. Some other users such as JekyllnHyde (R2 over at dpreview) also say they have not seen shutter shock either.
I've participated in threads over at dpreview, and have tried reproducing 'shutter shock' with the lenses and speeds others say they experience it, and still am unable to see a difference between using electronic and mechanical shutter.
My feeling is that if the issue can't be reproduced with non-IS primes (people seem to only see this with zooms), how could it really be called shutter shock? It seems to be somehow related to IS of zoom lenses. I'd like to see if we can collectively try to nail down what is really going on here.
Enough people have reported this issue to convince me that something real is going on here. If it is a universal problem with the camera, I should be able to reproduce it with my 3 M6ii bodies.
I invite people to share their experiences with 'shutter shock' on the m6ii fresh in this forum - and especially to share their experiences with the particular lenses, focal lengths, and shutter speeds they see this with. I'd like to reproduce it with my cameras and try to understand what it's all about.
[Edit] Sorry about all the edits, I keep thinking of things I forgot. Since this issue happens at relatively low shutter speeds, I think it's also important to mention hand-holding technique.
I nearly always shoot with an EVF, solidly holding the camera with two hands, bracing it against my face for 3 contact points. I would imagine if you didn't use the EVF and were holding the camera out if front of you with two hands, it would be more susceptible to a vertical lens 'bounce' when the mechanical shutter fires.