Originally posted by monochrome Doesn’t LX have a similar feature, sans the drive motor?
When you rewind the film on the LX, it does count the frame down. You can multiexpose a frame - accurately, forward or backward. Once you remove the canister, there are no guarantees for a frame accurate reinstallation of a used canister of film.
I had the Canon EOS3 and it has an infrared frame counter that will accurately resposition the frame so you can advance to the unused frame without wasting a frame to make sure you don't double expose any. I used this feature quite often - even multiple reinsertions of a canister, and not once did I double expose or even had a minor overlap.
Of course I fixed that issue by having multiple cameras . . .