Thank you very much! I checked and found a few at about 40/50$.
In term of adapter, what do you use? I say that there were some
AF-confirm adapter in M42 mount at 5/10$. Do you know if they
work correctly? Having focus confirmation could definitely be a plus!
Thanks again for the help!
For adapters, almost anything for $2 from China will do. Some of the lower-quality metals can get jammed on your camera and/or lens (but i've never had a problem on Canon bodies, mostly that applies to m42 on Pentax K bodies).
For AF chips, same thing applies, pay next to nothing and get a basic chip.
But for the best, I'd look for one by 'ml-gvalt'
on ebay. They're still fairly cheap, but the AF confirm works great, you can set the EXIF data to read anything (ie I've got one set to 50/1.4 on my Tak, 85/1.5 on my Cyclop, 35/1.4 on my Samyang). They also work with ETTL Flash, although I've never tried flash with a different chip, and you can AF Micro-Adjust from within the Chip, if you've got a 60D or less without AF MicroAdjust in the body. They're a bit weird to program, but once you get used to it it gets easier.