I'm looking for a source for lenscaps, hoods and filters in 40.5. When
I go to camera stores I am told that this is a rare thread size. I
haven't even had much luck finding them on the internet. I know it's not
totally common like 52mm but it can't be all that rare, I am currently
using five different lenses in three different systems that use this
Special order from B+W or Heliopan is an option. Alternately, get a step-up ring from B&H. I think that's a common size for enlarging lenses.
I use a series of 40.5mm filters on my Pentax Zone VI meter. I had to special order them from B&W.
Wasn't this a fairly common size years (decades?) ago, especially on various folding cameras? I've seen filters, adapter rings, shades, etc. in this size listed on E-bay.
try "the filter connection"
they list an 800 number on their website and have been very helpful in the past
40.5 is fairly common. My old Xenar is I think 40.5. Since I had no interest in getting one more set of filters I solved it by just getting a stepup ring. Calumet shows a range of filters etc in the size but considering the price ffor some of them I'd get a setup ring.
I just picked up a couple of 40.5mm filters for my Schneider Xenar 135mm lens. There are lots of skylight or UV ones around as I beleive some of the camcorders use that size. I have seen step up rings going fairly reasonable on E*ay lately. Colour filters for black and white seem to be the hard ones to find.
I've got a #25 an 80a and a rotating polarizer that I bought years ago when it never occurred to me that they would ever be difficult to find. Today, I have a 150mm Rodenstock, A 40 & a 90 for my L/M CL and an 80 and 105 for the Mamiya C TLR that all take 40.5. I really need a hood for the 40, a couple of caps. This place[ http://www.cameragear.com/cf.asp ] has Hoya double-coated filters for about twenty bones apiece.
I think I'll head down to the Second Sunday Camera Sale this week although I hate to pay the admission when I'm just poking around for odds and ends and I sure don't need any equipment temptations right now.
Tiffen has *tons* of 40.5 mm filters, step-up / down adapters, etc.
Try their web site.