>From: "Winston" <[EMAIL PROTECTED]> >I'll second that. 43 is an excellent lens, it's just that the optimum >performance comes 'late' at f/8-f/11.
I get the impression that this is fairly typical for Pentax designs. Is this because they use fairly simple and traditional optical formulas, or perhaps because the Pentax community tends to shoot in such a way that such optimization makes sense (i.e. scenic and landscape)? Most modern Nikon lenses seem to peak about f/5.6-f/8.0 which is a better fit for me--I rarely see f/11! With few exceptions, most lenses are pretty nasty both wide open and fully stopped down (due to diffraction). I'm told that a "perfect" lens should actually produce best performance wide open. Some of Nikon's big teles apparently come pretty close to this, peaking a stop or half stop down from wide open. This is not to say that these lenses are close to "perfect"--I suspect it is a question of design optimization. Apparently said long fast lenses are not so good stopped down past f/5.6 or so. Of course shooting a 200/2.0 at f/8 is madness! >I wished Pentax makes something wider than 31mm and longer than 100mm >Limited lenses. I'll second that. While I'm not likely in the market for any FA limited lenses (MAYBE the 77) they'd be a lot more tempting for me if they ranged a little wider and longer. >I'm not satisfied with the FA 24/2. Too much distortion, >and sharpness could be better at wide f-stops. Interesting. I've got a Nikkor AIS 24/2.0 that does not have a great reputation and did not fare well in my tests. I'd have expected the FA 24/2 (which has an aspheric element, yes?) which is a later design apparently aiming for a very high standard to be superior. Fortunately, I don't use a 24 much, preferring 28 and 20. For some reason both Nikon and Pentax seem to have done better at these focal lengths than at 24. DJE