The Pain of Adapting Lenses on Canon Full Frame Cameras - Part I

For those of you who never had to use your manual focus lenses on DSLRs, especially Canon full frame DSLRs, consider yourself lucky. Before there was mirrorless cameras on the market, the Canon EOS mount was the most adaptable digital SLRs for manual focus lenses. It can take Nikon F-Mount, Pentax K-Mount/M42-Mount, Olympus OM-Mount, Leica R-Mount, Rollei QBM-Mount, Exakta EXA-Mount, Contax C/Y-Mount, most medium format mounts, and possibly others. In theory, all the lenses of these mounts should work without problems, but like everything else in life, there are exceptions.

The Canon EOS mount can take other lenses is due to its shorter lens to sensor flange distance at 44mm, which is shorter than all of the mounts listed above. For example, M42 mount has a flange distance of 45.46mm. This means that if an adapter with a thickness of 1.46mm or thinner, is used to mount the M42 lens to EOS mount, the lens can focus to infinity. Some mounts, like the Exakta and Rollei, have a flange distance of 44.7mm and 44.6mm respectively, which means the adapter must be less than 1mm in thickness. Most of the adapters on the market that claim you can focus your Extaka and Rollei lenses to infinity are lying; none of the ones I bought could do that, except one I just got yesterday, which I will get to later. An adapter that's thinner than 1mm has at least two limitations: 1) it's hard to make it strong enough, 2) very hard to mount it on the lens without it cutting your hand with it's sharp, thin edge.

Adapters are just one of the issues. Even if you manage to get your lens to focus to infinity, for some lenses, there is another problem: the dreaded mirror blockage. What happens is that the rear of some lenses goes deeper into the mirror chamber than others and the mirror would hit the lens, especially at infinity focus. The worse Canon camera bodies with this issue is the 5D classic and 5D mark II. 1-Series of bodies are better, and cropped sensor bodies are the most compatible with the least trouble on manual focus lenses. In order to use their favourite lenses, some people has gone as far as cutting part of the reflex mirrors on their 5D/5D II! If you want to see an example of this, check out this link and scroll down until you see the 5D with its mirror shaved. Or, just image search on Google for 5D Mirror Cut. Personally, I wouldn't go this extreme. The good news is that newer cameras with Live-View partly solve this problem, by flipping up the mirror and shoot like a mirrorless camera.

Next time we will look at some of the lenses that won't work with the full frame Canon 5D/5D II.

Bokeh - Canon 5D Mark II & Carl Zeiss Jena Pancolar 50mm f2 @ f2. Click for larger.

New Toys from the Camera Show

I was debating whether or not to go the camera show today; last time I went, I spent more than I should and didn't get anything unique. In the end, gear addiction won, and my body had to follow so camera show I went. Met a few old friends there which was nice.  Ever since the old Henry's Outlet Store moved, those of us used to hang out there no longer see each other much, except at photo shows.

In a way, I am glad I went today. Got a few unique lenses, and most importantly, they are very reasonably priced. The Pancolar 50mm f2, which I owned a copy before but had problems, and sold it at the yard sale at give away price. The copy I got today is a beaut. It's in very nice condition and came in the Exakta mount. This lens will be a nice complement to my Pancolar 80mm f1.8.  We will see how it performs. If the Pancolar 80mm f1.8 is any indication, the 50mm f2 will be a fine lens.

Steve, who talked about Topcon lenses in the comments section of this post got me intrigued in these lenses. Ever since, I have had my eye and ear open for them and today my wish is partially fulfilled. Got a Topcon body with two beautiful lenses: 58mm f1.8 and 10cm (100mm) f2.8. Both lenses are in excellent condition. Frankly, I am overjoyed. Don't much care about the camera body, though it is in equality nice shape, but these lenses really make you fall in love with them. Steve is right, these are great lenses. I would probably try to get a collection of the Auto-Topcor and find the 28mm, 35mm, 85mm,  135mm and the 58mm f1.4 and any other focal lengths that they made.

Can't wait for the colors of spring to roll around and try out these lenses.

Three Amigos - Pancolar 50mm f2, Topcor 58mm f1.8, Torcor 10cm f2.8. Click for larger.