>From: Joe Wilensky <[EMAIL PROTECTED]> >I think I read somewhere (these days, who knows where I saw it?) that >with the launch of the K-mount line in the mid '70s, Pentax was >trying to compete with Nikon in the top-notch quality prime lenses >department, and that most Nikon primes had 52mm filter threads. Was >that seen as the "professional" size? Many of the designs that were >unchanged from the screwmounts look a little silly in these larger >barrel designs, such as the 35mm f/3.5. >Can anyone confirm? Maybe it was someone on the list who initially >referred to this some time ago. >Joe
I can confirm that the "standard" Nikon filter size was 52mm as the "standard" Pentax was 49. Most of my SMC-T lenses take 49, and pretty much all the rest take 58, which makes filter shopping nice. Most of the Ms take 49, of course. I haven't owned a lot of small K primes, but I do think the "elite" ones took 52 (K30, K50/1.4, probably others) although this may simply have been because they had to be that big at the time. I'd think that in general a deliberate move from 49-52 with the K series would have inconvenienced long-time pentax users. A move to "upscale" the K-mount line might account for the release within a few years of the K cameras of the K18, K30, and K200/2.5, all of which are impressive lenses, and also big and probably were expensive. DJE
