Hi,
I recently got myself a Yashica Scope and I am experimenting at the moment with various taking lenses. I found that the Zeiss Tessar 50/3.5 works quite well and it makes for an incredibly small setup:
(The Yashica Scope on an adapter ring on the Tessar 50/3.5 on an Exakta adapter on a NEX 5n - I wrote more on that setup here.)
Has anyone other good suggestions on taking lenses and ways to mount this thing (it seems that the thread is 30m but with a funky spacing - definitely not the one found on filters...)
best,
Tim