Filter for a Caltar IIn 135 mm lens

[Hany Aziz]

I know it is a 40.5 mm filter of which I have several. However I think my B+W filter touches the front element but it can be hard to tell. A Minolta 40.5 seems a better fit but again I am not sure. Is there an easy way to check for contact other than feel? I also don't want to damage my lens, which is my favourite. Tiny and so sharp! The equivalent Rodenstock is the Sironar N 135 mm lens.

Any filter brand that is guaranteed to fit safely.

Thanks.

Sincerely,

Hany.

[Peter K]

Place the lens on a table with the frontlens up. Than put a small piece of thin paper on the front lens and screw the filter carefully in. If the paper doesn't move, the filter doesn't touch the frontlens.

Peter K

[Joseph O'Neil]

I use the actual Sironar-N 135mm, and 40.5mm filters. I have a couple of B+W filters, and none of them touch the front element, even my 40.5mm B+W polarizer. Comes close, but does not touch
joe

[Steve Goldstein]

In the event it does touch, here's a trick...

Get a junker filter and remove the glass. Screw the empty ring onto the lens, then the real filter. The angle of view is not so wide that it'll vignette, and you'll get several mm of spacing.

[David A. Goldfarb]

I have that lens and haven't had a problem with filters touching. I have B+W screw-in filters and Linhof 42mm drop-in filters that work with the Linhof 42mm shade and filter holder (and I have others that I use with adapters).

[Sal Santamaura]

...I think my B+W filter touches the front element but it can be hard to tell....Any filter brand that is guaranteed to fit safely...

My B+W filter definitely touched the front element. One could readily see an interference pattern where the glasses "kissed" in their centers.

I had to special order one, and the process ended up taking many months, but a multicoated 40.5mm Heliopan UV filter is now fully screwed in with no front element contact. Apparently Heliopan rings place the glass further forward than do those of other brands.

[Bob Salomon]

Linhof 42mm drop-in filters that work .

Actually they were made for Linhof by Heliopan.