Using PB Lenses on EF (5D Mk1) Mount

CreamyMemeExtreme · Joined: 07 Mar 2016 Posts: 1

Hi

I've been googling around, and even have found some old threads on this very forum, but none seem to provide a clear answer. If I purchase an adapter like so: Click here to see on Ebay , will I be able to use the 50mm f/1.8 and 28mm f/2.8 primes with it? I've read in some cases one cannot focus to infinity, but I'm not sure what that means -- whether it's literally impossible to focus to infinity or at infinity focus the lens hits the mirror (which I'm very worried about).

I would be very grateful if some of the more experienced of you could put my worries to bed, mainly --

1. Can I use the two lenses mentioned above without issue, and if not --
2. What will be the limitations, and what potential for damage to my camera is there?

Many thanks in advance.

Attila · Expire: 2025-11-18

Depend from adapter need thin adapter to have infinity,many maker simple can't make it enough thin.

visualopsins · Expire: 2025-04-11

These can help:

http://forum.mflenses.com/viewtopic.php?t=3361

http://forum.mflenses.com/viewtopic.php?t=15761

Jiaming · Joined: 09 Mar 2016 Posts: 106

Theoretically yes, and some manufacturers do claim that they provide those stuff, but I haven't tried, so I can't say for sure. To judge if a lens is adaptable, the first thing to consider is the register distance, which differs from brand to brand. If the registration distance of your lens is greater than that of your camera, then it is theoretically adaptable. If not, although physically possible, you will not be able to focus to infinity. Links provided by visualopsins has some good information.
In your case, the register distance of Praktica B mount is 44.4mm, while it is 44.14 on a Canon EF, so it is possible, as long as the adapter is thin enough. A relative short register distance of EF mount makes Canons great for adapting vintage lenses. As for Nikon, the super long distance makes it almost impossible to adapt anything.
The second thing to consider is the mirror issue. When focusing to infinity, the rear element of the lens tends to obtrude into camera body, and might hit the mirror. There is no rule to follow, you only know it after you try it. On a APS-C body, there doesn't seem to be this kind of problem. But on an FF, like 5D, things can get troublesome. I don't know what kind of body you are using, but if you do use FF, please check it out here:
http://www.panoramaplanet.de/comp/#Prakticar
Also, 5D III is said to have bigger mirror clearance than the previous models, which means that some lenses that did not work on old 5D can actually work on 5D III. Pretty complicated. To be safe, focus to the close up end, use live view, and do the rest of your work.
Hope you enjoy photography with vintage lenses:)