Mikey ... bit by bit ...
Canon FD lenses: you'll need a very high quality (rare - v rare and ex - b prepared to spend at least SGD250-300) adapter with a glass element inside to ensure focus at infinity.
CZ (which range? There were NUMEROUS!). OK, let's assume the more popular CZ C/Y AEs or MMs - Offers outstanding image quality when used with a good adapter. I once used a rented combo of CZ C/Y 28mm f/2.8, Fotodiox manual adapter on a 5D, and the JPEG files straight-out-of-cam looked so much like processed files!
DEPENDING on WHICH lens, some, especially the wider ones MAY have a deeper rear flange, and that's gonna slam yr 5D mirror. Most users either file this down, or if possible, remove. You really have to do the research for exactly WHICH lense, because, as mentioned earlier, CZ and even the C/Y have many variants.
LEITZ R. Pretty much the same as the CZ range.
Note: for the CZ C/Y and LEITZ range, generally, you do NOT need an adapter with a glass element to achieve infinity focus. Also try to select non-chipped adapters.
Some of the best adapters cost between US $150 - $300, but these will allow you to fully realise the amazing optical qualities of these old world lenses. Unless yr a hard-core user of manual lenses, try the Fotodiox Pro range. They seem to offer competent quality at slightly lees than USD100 per fully manual adapter. In case yr wondering, minute machning differences as well as plano-parallell QC if fairly crucial to top quality results and consistency. BUT, be prepared for one fact - you need to MATCH each adapter to EACH lense. Just like precision target pistols/rifles and choice of ammunition, they can be finicky and have their own fave combinations. It's usually NOT a case of one adapter fits all.
IF yu get a competent adapter, and chose your lenses carefully, some, if not most of these old lenses can easily beat any Canon L lense. I have one Zuiko OM lens ... cheap budget shit, that outresolves the EF 100mm macro, with the Zuiko WIDE open, and the EF macro STOPPED-DOWN!!!!! Cost of this lens? About $100 in superb condition, and about $50 in a beat up condition. Mine IS beat up, and still outperforms the EF Macro lense!
My 1st Edition Vivitar Series 1 lens, when closed down say half to one stop, and IF it's properly mounted (adapter issues), can FULLY MATCH my 702002.8. You could get that Vivitar lens for typically about US$50 - $100 these days.
IF you are really serious about getting into the wonderful but sometimes frustrating world of old manual lenses, let me know. IF yr serious, cos it's going to take quite a bit of effort and dedication on yr part to achieve optimal results.
