Originally posted by coqui I recently acquired this lens along with the 1.7X adapter, and I need some help in trying to determine a fair value for this lens. I purchased a 43 Limited last night, and I have the FA50. It seems that it has some collector value, but I am not sure. All suggestions are welcome.
It is NOT a rare lens. It was widely available and comparatively inexpensive when the Pentax SF-1 and the SF-10 cameras were current models and many copies were sold. The SMC-F series was Pentax's first AF lens line, and many users did not like the narrow hard plastic focus ring. With the next series of AF lenses (SMC-FA) they switched to a slightly wider, rubber-textured focus ring. The FA lenses also have an updated computer chip that sends additional data back to the camera for newer cameras. Otherwise, many of the FA lenses, including the 50mm f1.4, are identical to the F series predecessors.
The optical design of the 50mm f1.4 is unchanged since the SMC-M 50mm f1.4 from the '70s. Similar designs are used in most 50mm f1.4 lenses from most manufacturers. (It is a 7 element derivative of the 6 element Zeiss Biotar from the 1950's).
I think that any claim that the SMC-F 50mm f1.4 is "a collector's item" or a "rare lens" is pure bunk. It was a widely-available, mass-produced lens with a well-know, tried and true optical formula. It is essentially the same as the SMC-FA 50mm f1.4 that is available new at a low price. If you want to sell your used copy then I would price it accordingly.
(Note: there was someone who was selling one of these lenses in the Pentax Forum Marketplace some time back. The seller made ridiculous claims that this lens was some kind of rare collector's item. That was just a load of bull. Do not rely on that fraudulent listing in describing your item.)