Hi @lee - funny you should mention electronic first curtain, as I was just thinking about it the other day. I had experimented with it, and then rejected using it, and then forgot all about it until I saw my camera make a funny jarring movement when the shutter was released, even though the camera was on a tripod and I was using a remote release.
Apparently there are some limitations on using electronic first curtain that should be considered, some of which apply to any mirrorless camera and some of which only apply to some Sony cameras. I put several links for information about the topic at the bottom of this page, Section C, under “Issues with Electronic Shutter and Electronic First Curtain”:
FWIW, I don’t think the jarring motion I saw would have happened if the camera itself was directly attached to the tripod. But in the particular case actually the camera was attached to a wooden frame (that in turn was attached to the tripod). My very talented husband put the frame together to allow attaching an old Tamron zoom lens to the camera without asking the tiny Sony A7 to hold the weight of such a long lens. He’s planning to modify the point of attachment to hopefully eliminate the slight jarring.
It’s nice to know that “totally silent” really is possible, something I’ll look for in my next camera.