Originally posted by falconeye My proposal is meant to enable the use of XS lenses on Pentax dSLR bodies, where e.g., the RAW button activates MLU and the firmware prevents the camera from moving its mirror as long as the lens is mounted.
And again, if the battery dies the mirror will go down - the firmware cannot prevent this. Is holding the mirror up - for a camera that wasn't designed for this - an energy free operation? I doubt it. It's nowhere near a "risk free operation", even if correct, careful usage is ensured.
I don't understand why are you against hardware changes that would make it work better and safer. A mechanical lock for the mirror, a method of preventing the mounting on incompatible cameras, an EF-S-like way of raising the mirror which could grant full compatibility... not everything can be solved by software
By the way, most Pentax DSLRs require the mirror to come down after each exposure in order to be able to shoot again. The K-5 is an exception.
That's exactly what I'm doing, discussing your idea, trying to improve it and to think of alternate solutions. Hopefully this way we'll have better ideas, and see some of them implemented on future cameras (or even past ones, if a firmware will suffice).
For this, a little bit of flexibility when valid arguments are presented is required.
P.S. The 40mm XS won't break it
And it certainly can be used on the K-5.