I don't know... the Jupiter-8 is ok... kind of charming and all, but low contrast and not really all that sharp (even stopped down)... not saying it isn't worth the money, just that it's only ok (pretty lens on the camera though). The Industar-61L/D is a very good lens, it's just ugly (if that matters to you). I don't think you can collapse it all the way in, but people put a rubber ring on the Industar-22 (Elmar clones)... and those are very good coated lenses stopped down a bit. I am very happy with my Color-Skopar 50/2.5... very sharp and nicely pleasing... maybe a mixture of old and new feeling IMO... I like it. *I* haven't seen a nice LTM Summicron 50 for under $300... really wish I had 'cuz I would have bought it. They are nice enough stopped down, and probably the very cheapest 50 you can buy, but a Industar-26 is pretty good... might even get a good working FED-2 attached to it if you are lucky!