the Canon 50/1.2 LTM seems to vary alot between copys, my latest seems to work pretty good, very very dim here. This is on APS-C
original
http://farm6.static.flickr.com/5030/5601618575_aa848e761e_o.jpg
The nokton 1.1 actually has similar OOF in my tests, and of course is sharper at all apertures, but the canon I'm finding far more practical. It's dramatically lighter and shorter, and the DOF is much easier for me.
This Canon 1.2 copy has some filter scratches, and a few other hairlines on the front element, but the rear and inner elements are totally free of haze and cleaning marks. I will say that in low light it has surprising contrast. Paid 450. Ouch.
When I stop it down its not bad, but my Canon 1.4 LTM walks all over it at f/8
In fact maybe that's a lens to consider. Good copies running about 280, and it's almost 100 grams lighter than the 1.2.
Here's the 1.4 wide open on the battlefield:
I'd assume the 1.5 is equally variable. The jupi 3 would be great IF you find a good copy from US seller, I think Brian said don't get the black one.
I do hear folks raving about the CV 50/1.5, which I think can be found for under 400.