Originally posted by Clavius Reallly? I'm a Pentaxian, and I would greatly appreciate a new mount. Because without a new mount SR won't be possible.
I don't believe that you can say this is even remotely true. At best (or worst, perhaps) you can probably say that some of the older lenses do not project a large enough image circle to work with a body stabilisation system, in some circumstances. You could possibly also say that stabilisation will only work over a limited range of movement. You can't, however, use an absolute phrase like "won't be possible" and I doubt that you could justifiably use "won't be practicable", either.
There is a belief, based on inadequate evidence, I think, that the full range of sensor movement shown to occur in the Sony IBIS system is needed for adequate stabilisation in a future Pentax K-mount FF body. However, I will defer once again, for those who missed it the first, second or third time around, to Falk's contribution on the subject, as quoted in the thread on this subject:
https://www.pentaxforums.com/forums/pentax-k-5/200214-ibis-road-block-pentax-...ml#post2137167.
Of course, if anyone has a more convincing position on the subject, then let's see it.