I understand all Pentax 645 lenses being manufactured today cover the 42X56mm area. Right?
If this is true, doesn't this hint that a full-frame 645 body will come sooner or later?
Most of these "FA 645" lenses were originally design for 645 format film cameras, before the 645D. I only know of one new "FA 645" lens that covers the 70mm image circle of 645 format even though covering only the 55mm image circle of 44x33mm would have simplified the design: the 55/2.8 mm. Some plausible explanations for that include:
a) covering the possibility of returning to 645 format, and
b) making that lens attractive to the many people still using Pentax 645 film cameras (who greatly outnumber owners of the 645D), and so increasing its sales.
P. S. The 25mm is an "DA 645", meaning I think that it only overs the smaller 44x33 format. What other new "645" lenses has Pentax introduced since it discontinued the 645 film cameras?