Originally posted by Loren E So, any ideas as to why this lens got changed to 49mm? Any recommendations on good multi-coated filters that won't break the bank for this lens? Sorry for the rant!
-LE
Agree that having to buy bunch of filters of different sizes can be annoying. But why the change to 49mm, I'm guessing because most of the Pentax lenses, especially the small primes use 49mm filter. So while it's bad for you it's not necessary bad for others who happen to have a lot of Pentax primes.
Smaller filter means smaller lens and small is a theme of Pentax. Pentax has been revising their lenses formula to achieve smaller lens (and with smaller filter as the consequence) ever since the introduction of the Pentax-M series.The 50mm 1.4 for example, the original version (M42) has 55mm filter size but now it has been since changed to 49mm, same as the D-FA 100mm macro, it uses 49mm filter while the previous version F & A used larger diameters.
On a side note, AFAIK 52mm filter size was introduced by Nikon (at one time Nikon was promoting one universal filter size), other manufactures usually prefer to use 55mm then skip to 49mm. There are exceptions of course, but I don't think there's many Pentax lenses with 52mm filter size. While I never actually found such claim I think 49mm is the preferred (universal) filter size by Pentax.
I actually decided to buy D-FA 100mm instead of F 100mm which has better reviews, because it is smaller and it uses 49mm filter. Because I already have invested on good 49mm filters (CPL, ND4, ND8 & IR) for my other Pentax primes.
But of course the world is not ideal
So I do have some lenses with 52mm and 55mm filter size. I solved the problem by getting step down rings (52to49 & 55to49). All these lenses are normal to short tele so I don't get vignettes even when using the slightly smaller filters. As a bonus, the step down ring also acts as a short hood similar to DA 40 and DA 21 hoods.
I also have some big lenses requiring big filters, up to 77mm, but for these I just don't bother to use filter or just buy a protector / UV filter and that's all.
So to end this post, I think you are making a good investment by buying 49mm filters because well, if you buy more lenses in the future, especially the Pentax primes, you'll likely find them very useful
Last edited by sajah; 10-14-2010 at 01:59 AM.