Originally posted by jaad75 How could they, if they have different focus point counts?
Because the K-3/ K-3 II's autofocus is somewhat crippled.
What follows is based on the recent rediscovery of an older post by
bwDraco/DragonLord:
https://www.pentaxforums.com/forums/172-pentax-k-3/297512-how-much-better-af-...ml#post3287934
In the viewfinder of a K-3 or K-3 II there is a significant gap between either side point and the main AF area.
There are
seven columns of selectable AF points in the viewfinder but
nine columns of physical sensors in the AF module.
(note that the five inner lines of physical sensors in the AF module correspond to the five lines of cross-type sensors and the three outer lines, with their enlarged telemetric base, correspond to the three f/2.8 sensors)
The two extra columns, which appear to be unused on K-3 / K-3 II, would be enabled on K-1, each for three AF points, thus giving a total of 27 + 3 + 3 = 33 AF points, of which 25 correspond to cross-type sensors, as indicated by Digital Camera Info.
Judging by the spacing of the two brackets inscribed on the focusing screen of K-1, as seen by reflection on the mirror and which most likely correspond to the outer AF points (as with other Pentax cameras), it seems that Ricoh Imaging has found a way to enlarge the AF point coverage
compared to what the K-3 / K-3 II module would spontaneously produce on K-1.
Finally, remember that Ricoh Imaging have been granted a patent for a concave secondary mirror to enlarge the coverage of the AF module:
Ricoh ?????????AF?????????????????So-net???
Et voilą!