I am using several FSU lenses on my Bessa cameras, in fact, the Jupiter-8 I have is my main lens. I am either lucky or not critical enough( or, possibly, both) but the specific J-8 I have works very well with both my R and my R2a.
This is not always the case with FSU lenses.
I did have a J-3 that was well adjusted for the Bessa (thanks, Brian!) but I just didn't like it as well as I like the J-8.
I have also used most of the other FSU 50's on my Bessas with pretty good success. Again, I may not be critical enough to see the potential problems.
Of those I used, I liked the Industar 61 the least; it had--for several example I owned--pretty decent optics but the lens just felt a bit shoddy to me.
The Industar 26 and 26m lenses I've used seemed much better to use for me. And are, again for me indistinguishable from the later I-61.
And my second favorite FSU 50 is the rigid Industar 50 that I own. A bit slower that the others with its f3.5 max aperture and it uses a pain in the butt 33mm filter thread. Still, I like the results from it quite a lot.
The collaspible I-50 is also pretty good but I was always a bit nervous using it on the Bessas; I was concerned about collapsing it too far and damaging the camera.
I also liked the Indusatr 22 but, again, wasn't comfortable using it on my Bessas.
Though, I did recently get a rigid version of the I-22 that I'm still learning.
You might notice I like the FSU 50mm lenses!
There are some other reasonably common FSU lenses available that I also use on my Bessas: the Jupiter-9 (85mm/f2) and the Jupiter-11 (135mm/f4.5).
The J-9 is notorious for not focusing well on Leica standard cameras but if you get one that can be and is adjusted correctly, they are very good , too, I think. Mine is anyway.
The J--11 is, in my opinion, as good as any 135mm lens around--newer lenses will have better coatings but for my eyes the results with my J--11 are just fine, thanks.
And then there is the Jupiter-12 (35mm/f2.8) lens. A lens that I like but that doesn't play well with the Bessas; it has a very large rear element that (in most cases) will hit the interior of the Bessa and they will also block the meter sensor. But the J-12 will work just fine on your FED, although you will need an external viewfinder for it. In fact, you'll need on for anything other than a 50.
There are certainly lots of better lenses for the Bessa R cameras--all the CV offerings come to mind--but for a fairly low investment, you can have a decent lens kit that will serve you well.
Good luck!
Rob
