Originally posted by Kunzite The A7r is known for its harsh, loud shutter release; I would be surprised if the K-1 won't be significantly better. And, more mass helps here.
agree with all that, if you need to quantify k-1 shutter shake artifacting, the d810 link i posted would probably be more accurate... but that's not why i posted the a7r ss photo.
the a7rii has basically the same shutter as the a7r, the shutter shake measures out to be nearly the same... nobody talks about it because of the xlnt efcs implementation on the a7rii.
canon also redesigned the 5ds/5dsr shutter, but they still warn against mirror flap:
"Minimize any slight vibrations from mirror movement
Canon engineers have taken the first step here with a mirror system that’s now motor driven and cushioned at the upper and lower ends by a sophisticated mechanical system (not a simple foam pad or similar “solutions”). Regardless, especially at those critical slower shutter speeds like 1/125th down to perhaps 1/2 or 1 full second, EOS 5DS and 5DS R users can help. Consider trying Live View (especially with Silent Shooting Mode 1 or 2 active).
Or, use conventional Mirror Lock, ideally with a Remote Control switch (electronic cable release). Mirror Lock now also has delay settings, from 1/8th to 2 full seconds, for shooters who want to continue to use the eye-level viewfinder, but achieve the benefits of letting the camera “settle down” from any fine harmonic mirror vibrations before the shutter opens"
https://www.learn.usa.canon.com/resources/articles/2015/eos5ds-eos5dsr-files.htmlp
that entire link is interesting reading.