Originally posted by paperbag846
So it's still great, but I fear a lot of people miss out on what makes the 31 *truly* special... the rendering of a portrait lens, with the FOV of the DA 21 on a digital camera!
To me, this is one of the strengths of the FA31 on an APS-C camera. It is a "wide normal" lens with unique rendering characteristics that distinguish it from other "normal" lenses, which are almost all longer. It also has extraordinary sharpness and jewel-like construction. (In my personal experience, the only comparable lens in its league is the Zeiss Contax G 45/2, which is a FF film lens.) If you happen to like that particular focal length, as some of us do, then it is ideal for many uses and gives spectacular results. BTW, how many other "normal" lenses are there for APS-C? A 35mm lens is equivalent to 53mm on FF vs. 46mm for 31mm, a small but significant difference. A DA35 might serve the purpose, if one likes its rendering character and can accept the loss of speed. A 28mm lens is equivalent to 42mm, and the FA28 is not even close in quality. There may be some lesser third party alternatives, but that is not what we are discussing here.
I have not seen any evidence that the character of the FA31 is different when shot on a FF vs. an APS-C camera, although I fully expect that a digital sensor, especially like the one in the K-5, will win by a large margin over any film in terms of IQ.
So it seems that your argument comes down to one of effective FOV, which is purely a matter of personal taste and shooting style and has nothing to do with lens quality or character. I'm glad that we have finally gotten this straight, so in the future, when you want to argue that the FA31 is not worth what it costs, please make this point clear. You personally do not find the focal length particularly useful, but kindly allow that others might and that there are few, if any, alernative lenses that can match it. It is pricey, but that, too, comes down to personal factors, such as budget and willingness to spend.
Rob