Originally posted by mattb123 I think to do mirrorless right they need a new mount.
I believe many of us have a mirror-less camera and some lenses already, as a 2nd system or backup.
If pentax changes mount, I will keep what I have right now and probably will not pay a lot $ for a 4th system (after K, NEX/Alpha, Q).
Originally posted by Float Rangefinder lenses have very short flange distances and incredible optical performance.
Many of them are great, but they are not great because they are RF lenses. RF lenses have a lot limits, such as minimum focus distance and edge performance on the wide end. I am sure many test/review will report not up to the "excellent" standard if the lenses are just released by other lens makers. I like the special taste and character, but these "taste and character" can also be interpreted as shortcomings for someone else.
Sony had to add the distance back to the end of lens mount on the G master lenses, for obvious reasons. No optical design can completely overcome this issue unless curved sensor is available.