Originally posted by burzum Pentax DA 15mm f/4 ltd
Pentax FA 31mm f/1.8 ltd
Pentax FA 77mm f/1.8 ltd
This would likely be my triad, as well.
I own a gang of legacy K, M and A primes, including a pristine A* 85/1.4 (none of which, for all practical purposes, I ever use). I also have a DFA 100 macro, all five DA Limited primes, an FA 31/1.8 (since December) and an FA 77/1.8 (since last week).
I'd suffer no internal debate over the 15 and 31; I've been captivated by both since the day I got them. The "long" choice is a tougher call. At this point, I've little experience with my FA 77, but based on what I've seen thus far I would pick it over my DA 70 simply because the 77 is slightly faster and has a marginally longer reach; both render fine images that have differences that I easily discern, but I've yet to decide which I prefer. My A* 85 also performs impressively, but lacks AF (to which I've become dependent in my advancing years) and has the mass of a sub-compact car.
Jer