Originally posted by alamo5000 That said I wouldn't wince at a 28mm. It was my favorite focal length on crop but there isn't that much difference between 28 and 31 if you ask me. Not enough to warrant extra space in the bag....
Assuming the 31 is in the budget. The FA 31/1.8 Limited was originally released along side the 28mm offering, not in lieu of. Now if Pentax were to release updated HD D FA 31/1.8 DC WR at a price point similar to the very excellent 28mm offerings from Nikon or Canon, that would be excellent. The current FA 31 is twice that money.
For a K-1 owner wanting a true wide angle capable of doing landscape and interiors with minimum distortion or reasonable crop options to final dimensions, 24mm is way overkill and the FA 31/1.8 is overly expensive. There is a reason why the 28mm was a part of the classic kit and why the various K-mount 24mm lenses are fairly rare used. The 24mm focal length is a little too wide for general use. The relative rarity of 24mm and 20mm lenses used is the result of poor sales back-in-the-day.
Oh...BTW...I too can't figure out why so many people seem to feel that any future wide angle must be f/1.4 or even f/1.8. In case they have not noticed, even with a high magnification viewfinder it is fiendishly hard to use unaided manual focus at 24mm or even 28mm on FF. AF does not help since even the best AF points for PDAF have a focus sensitivity of f/2.8...yes, 2 stops slower. Yes, there is live view and that is an excellent option for on-tripod work in other than bright conditions.
Steve