>>2866101>If it did close when no lens was detected, every adapter would have to have a readable CPU, or you'd have to menu dive in order to turn the option off.That occurred to me, but all they'd have to do is put a little switch in the mount that detects when any lens or adapter is clicked in. It wouldn't require any kind of CPU contacts or anything, just something that would be depressed when a lens was in the mount.
The only other thing I can think of is that shutters are pretty fragile, and maybe they feel like a closed shutter is more likely to be damaged while changing lenses than a bare sensor is.
And in response to the other posts, yes, modern mirrorless cameras absolutely have mechanical shutters. Here's a photo of the one from the A7SII. I can't find a picture of a Fuji shutter but they also definitely have them, in fact the one in my X-Pro2 was a pretty big deal in Fuji's marketing.
