Recently I have been experimenting with my Russian and GDR lenses on my digital Pentax K10D to compare with results on FILM -- I used the Pentax M42-Bayonet adapter and 'AV' exposure mode and had to use +1.5 exposure compensation or camera under-exposed. I found the MC Jupiter-9 f2 85mm was 'soft' at full aperture but OK from one stop down f2.8 -- I also tried a GDR Pentacon f2.8 135mm M42 lens and all had to be taken at full aperture as the aperture is STUCK fully open ! I have TWO types of Russian Helios f2 58mm lenses, one with WHITE aperture markings from the KMZ Factory and one with GREEN aperture markings from the VALDA Factory but have not fully tried then out yet . Can I put a 'digitally -taken' photo of the lenses in the 'pool' ?

Nice collection of lenses. I have a Jupiter 37a and wouldn't mind having the Jupiter 9.

I want more collections.

There are lots of interesting USSR and GDR lenses around. For example the MIR-1 which is a Flektogon clone - bot of them are excellent and very sharp. The Helios is one of my favorites with its crazy bokeh. The Zenitar 1.7/50 is a bit on the lower contrast side wide open. It renders adorable tonality. The Industar 61-LZ is designed to be a macro lens. It has low contrast but renders materials in a very detailed and realistic way. Great for portrait photography too. Combined with the right film, these lenses can produce beautiful photos.