Originally posted by SylvainB It would happen if Pentax was giving signals on the lens side. No new (real new) lens since... I don't even remember. Going to 100MP or 150MP full format without new lenses would be a bad move. The 90mm would be OK I guess, but for the rest, no idea.
---------- Post added 09-02-18 at 04:11 AM ----------
No need, the flange distance didn't change since film era. Did Pentax change the K1 flange distance in comparison with K3 and other APS-C cameras ?
---------- Post added 09-02-18 at 04:12 AM ----------
Then you know what to do : apply for a position at Ricoh / Pentax
Lenses only work properly if flange distance / registration distance stays the same. If not, focusing issues will arrise.
We can use Pentax FF lenses on Pentax APSC cameras and also older Pentax middle format lenses on the 645D/Z camera. This is possible since the registration distances are the same for each couple. At least that‘s my understanding.
Problems may occur concerning image circles if a lens is designed for a smaller sensor size than the ones for the standard analog film original formats. Most APSC lenses show strong vignetting on FF cameras like the K-1, they are not FF compatible. Same may occur with lenses designed for the 44 x 33 mm middle format sensors. The image circle of the lenses may be too narrow for a real, not „cropped“ Pentax middle format camera.