I am a bit confused with the A and E designations. As I understand it A means slip-on and E means screw-in. E39 is 39mm screw-in and A42 is slip-on. So on a lens that uses E39 you can screw-in a 39mm fliter and slip-on a 42 lens cap.

My 90mm f/4 Elmar is listed to take E36 or 36mm screw-in. But the filter adapters are listed as A36 slip-on. How can a lens use both screw-in and slip on of the same size? If it uses E36 then how would A36 slip-on fit as well? I would expect that for 36mm screw-in it would take a 39mm slip on.

Or is A36 really larger than 36mm and slips on just fine?

Thanks!

Tony

-- Tony Oresteen (Aoresteen@mindspring.com), October 07, 2001

Answers

Where is your lens listed to take E36 filters? All the resources I have indicate that 90/4 Elmars took A36 (early) or E39 (later). My 90/4 front rim has an outer diameter of approx. 35.5mm and takes the A36 slip-on filters. There are threads inside the front rim which resemble filter threads, but the diameter is 33.5 and I suspect the threads are there only for the retaining ring for the front element. (If there is such a thing as a 33.5mm filter it might fit, assuming the pitch was the same.) If you get yourself a millimeter ruler you can check your lens and you'll know for sure what kind you've got.

-- Jay (infinitydt@aol.com), October 07, 2001.

I've seen it listed both ways on a number of sites on the net. I just checked Sartorius' book on Leica lenses and indeeded you are right; he lists it as an A36. I just bougth the lens and it hasn't arrived so I'll have to wait until the UPS man drops it off to measure it.

Thanks!

Tony

-- Tony Oresteen (aoresteen@mindspring.com), October 07, 2001.