Originally posted by reh321 As I indicated above, I'm not convinced that an adapter would have to do anything with mechanical aperture control. I believe a K-mount lens could be handled exactly as an M42-mount lens is handled on a usual MILC, and in fact, how an M42-mount lens works on my K-30 or even on the Super Program I purchased in 1984 - never touch the mechanical aperture and use the lens stopped-down the entire time.
I see what you're getting at, but for my own uses - and, I think, the general success of such a camera - this wouldn't work, IMHO.
I'd want the camera with adapter to fully support my existing K-mount AF lenses with full aperture control, so I can benefit from the light gathering and depth-of-field control. Again, I compare to Sony's A7-series, where legacy and current A-mount lenses can be used with no limitations (at least as far as the lenses are concerned) on those bodies using the LA-EA4 adapter.
I know several Sony E-mount photographers who, even with the availability of some good native glass, choose to use bigger adapted A-mount lenses either because they're faster or they already own them, and they integrate perfectly with their E-mount bodies via the adapter.
So, I'd definitely want mechanical aperture control on the adapter, and I suspect quite a few others might too...
EDIT: As an FYI, of the M42 lenses I own, most have manual, preset, or switchable A/M aperture control. For those that are auto only, I've modified them to work as manual. For my manual K-mount lenses, when using them on my Sony A7II I fit a K-to-E-mount adapter with manual aperture control. It works, but it's not ideal - and it certainly isn't a good substitute for an electro-mechanical system linked to the camera.