From the mailbag:
I see you have a Sony a7 II. Does the internal stabilization help with the shutter shake?
The a7II doesn’t suffer from shutter shake, if you use electronic first curtain shutter. If you turn EFCS off, it does, but you only would do that if you were going to use a very high shutter speed.
Does the construction of the lens mount on the 7 and 7R affect shutter shake? The 7S an & 7 II seem to have a more robust mount and there is a way to retrofit that robustness to the 7 & 7R with the Fotodiox mount upgrade.
It’s possible that there is enough flex in the a7 lens mount to affect the shutter shock, but if you care about the effect, you’ll turn EFCS on, and then it’s not a problem. The a7R lens mount is more sturdy than the a7 one. I suppose that replacing the lens mount with an even stiffer one could help on that camera, but I think it’s a long shot.
The Leica M240 has a nice sturdy lens mount (beefed up because Leica expects some of their customers to use R-series lenses on it), and it suffers from shutter shock if you don’t turn off live view before tripping the shutter.
You seem to have worked out a good way to test the shutter shake. It occurs to me that you could have mounted a big copal shutter via an adapter in front of some lens and then tested the 7R in without its shutter having any effect.
Or I could rig up a Linhof lens board to Sony E mount converter and just use view camera lenses, if I could figure out a way to trip the shutter. But what I do now is simpler. When I want to see what a target looks like without shutter shock, I darken the room, set the exposure time to 2 seconds or longer, connect a Paul Buff Einstein with the flash duration set to 1/13000 second, and use trailing curtain synch.