I've been selling my gear off and was thinking what sort of budget kit might be kept "just for fun". My FD 135 2.5 is a no brainer for a tele: cheap, and has wonderful IQ. I looked at some negs from an old Helios that I'd put on a Canon FT QL w/ an adapter, and that made my decision for a 50 lens (or a 58 actually). It's remarkable how nice a kit you can put together for under $100.
Here's the Canon, and the link below it is to some shots from that Helios. I've always appreciated Russian glass on rangefinders, but their SLR lenses are just as good.
I've got one, it came in a Zenit kit I got for nothing; I can't bear to get rid of it because of its "Battleship Potemkin" feel, but I can't remember the last time I took a photograph with it ...
You should shoot yours. The photos they make are amazingly good. Leica sharp, and wide open thay are perfect for portraits. Bokeh can be quite swirley at times, but more often than not it's "normal". I like the bokeh thing myself. Mine came off a Zenit 11 that had problems....namely, it was a Zenit :] The old Canon works just fine w/ a $10 adapter in stop down mode.
I used to use it as a macro lens on digital with an extension tube, and it was quite amazingly sharp and contrasty.
I don't have a film camera I can put it on since the zenit committed suicide. If I ever see a m42 body for a fiver I'll buy it and give it another go
If you have good copy of this lens, it is worth to keep it.
Two guys, I know in my town, have Zenit with this lens, works and sharp.
I wasn't lucky with my 44M.
I had one on a Zenit E. It did not seem very special to me. I know there was sample variation. A 55/1.8 SMCT or SMC is probably my favorite slower M42 standard lens and these are also available for very little. Good standard lenses have been available for a long time.
Just sold my 44M. Had it for a month or so to try it out, it was sharp but nothing special and in strong backlight it flared quite a bit (was clean inside). I was hoping for maybe some interesting rendering (a la Voigtlander 40/2 or Zeiss 50/1.4) but didn't see it. Still, for £10 it makes an interesting standard lens.