Originally posted by brofkand Popular Photography in the early aughts rated the FA Limiteds as the best lenses on 35mm period - for any mount and for any system. Including Leica.
They are sharp sure, but a cooke triplet is sharp as well. They have a certain rendering that can't really be replicated. The FA 43mm, the only one I currently own, never has its rear cap affixed because it's always on one of my cameras. I might as well cement it onto my MZ-S.
You should begin by reading the reviews on Pentax Forums submitted by users. They're all here, in the FA Prime section:
Pentax FA Prime Lenses - Reviews and Specifications - SLR and Interchangeable Lenses - Pentax Lens Reviews & Lens Database The digital rev reviews seemed pretty scathing. Although, I just looked, the review on here for the 43mm do seem very good. However, there seem to be several comments like
"Sharpness:
I gave this a 5 because when it focuses, it's pretty good, especially at screen size. But a pixel peep reveals that the lens lacks the resolution of its FA31 and FA77 sisters. Perhaps the biggest problem with this lens is its poor contrast, even stopped down until you hit f/5.6 or so. Using flash helps a bit but compared to what other lenses can do on the K-1, the FA43 is a huge disappointment.
I'm not even commenting on wide open performance. I'm trying to shoot this at f/3.2 to f/4 and not seeing acceptable results. Flash helps a bit but the off-center performance is quite poor even stopped down a bit. A normal lens like this should really be accomplishing a lot more." from MadMathMind
And none of them are *that* fast. I have a 50mm 1.4 (8 element) takumar that you could say similar things about (although without af, somewhat less sharp, and a stop faster), and it cost about a fifth as much.
Maybe I'll just have to try one and see