Originally posted by Kds100 Frank, after I read about this here, I tried a Google search looking for more information but found none (aside from what I assume is your post with the same info at DPReview). Can you point me to the source(s) of the information about the coatings and serial numbers? Hopefully it'll be in English
Sorry I'm afraid I can't be much help here. I read this at a couple of Chinese photo forums, all in Chinese. The original source was from one guy in Taiwan who has bought over 20 copies of FA43, and played over 100 (from friends, shops and etc) copies. He is the one who came out w/ the following types:
SMC PENTAX-FA 1:1.9 43mm Limited
Type-1 0000001~00160xx
Silver Version
Type-2 0013xxx~0015xxx
Black Version
Type-3 0016xxx~0019xxx
Silver & Black
Type-4 0020xxx~0023xxx
Silver & Black
Type-5 0023xxx~ Still in production
Silver & Black
This guy claimed type 2 and 3 might have the best built and optical quality. And the coating in the earlier versions (type 1, 2, 3) might be different from the later versions. But I guess nobody can confirm this, not even Pentax. It's more like speculation to me, any difference in tests is more likely due to sample variation.
But because of this, the early types are more sort after ones, sometimes even can fetch slightly higher resale prices, at least would be easier to sell.
I myself have had 3 copies of this lens, the one I'm keeping is a silver one w/ a serial number of 15xxx
Cheers!