Last Feb I took my Contax IIa to San Juan for a vacation. I had a bit of trouble looking through the finder as I need a +2 diopter to see and I don't like using my glasses. Since I have diopter lenses for my Leica M camersa that screw in, I thought that an adapter would work. I sent my IIa to SK Grimes with a Leica diopter and asked them to make an adapter. I got my IIa back from SK Grimes and they were able to make a nice adapter so I can now use Leica M diopter lenses on my Contax IIa. I can SEE again!!!!!!!! Cheers to the lads at SK Grimes! Here's the IIa eyepiece: Here are the adapter and the Leica diopter M 1.5: Here's the adapter in place: Here's the diopter mounted on the IIa: A side view of the adapter: The cost was a very resonable $65 from SK Grimes. www.skgrimes.com Leica M diopters are $100 new from B&H. http://www.bhphotovideo.com/c/product/30071-REG/Leica_14353_2_0_M_Diopter.html They pop up on eBay once in a while. Overal this is a great mod if you need diopter correction for your IIa or IIIa cameras. I can really see clearly now!