Lens Hacking – the easy way

Lens Hacking – the easy way

I became interested in photography when I was going through High School. I spent the first two years working in the schools darkroom (read: storage closet that also held a photographic enlarger). I also spent those first two years borrowing a Pentax K100o. Shortly before graduation, my Grandfather gave me an older Revuflex T SLR camera that was his when he was in his 20’s and 30’s. I used that camera for a year or two, and eventually upgraded to a k1000 own.

Dusty Revueflex T Film SLR Camera with a Mamiya Sekor 50mm 1.4

Dusty Revueflex T Film SLR Camera with a Mamiya Sekor 50mm 1.4

Now, for those of you who are unfamiliar with these types of cameras; they are built like tanks. Made from aluminum or steal. They are heavy, and fairly large for what they offer. They worked only as a manual camera: manual focus, and manual exposure. The Pentax k1000 was somewhat unique, in that the k mount lenses that it used were very common. I read somewhere, that there are 25+ million K mount lenses out there in the market. That is a lot. The collections of lenses available to a k mount or an m42 screw mount are vast.
I eventually bought in to the autofocus idea… and after getting my first camera, was very disappointed in the amount of lenses available and the cost of said lenses. I shoot canon now, and while canon does have a significant lens catalog, I have always found my collection missing a few special purpose lenses.
Then I bought a Canon EOS M. If you want to put an older canon manual lens on your canon ef mount camera there is a little thing that you need to understand first:

Diagram Illustrating the Flange Focal length of an SLR–type and a mirrorless–type camera

Diagram Illustrating the Flange Focal length of an SLR–type and a mirrorless–type camera

Flange Distance. The flange distance is the space between the back of the lens mount to the film, since we are talking about slr cameras, there is also a mirror in there that has to clear the back of the lens, so the lens can not stick out in to the opening of the camera. Canon manual lenses had a flange distance of 42.oo mm, the canon ef mount flange distance is 44.00 mm. The 2 mm difference does not sound like much, but it is enough that a Canon FD manual lens will not be able to achieve proper focus. Flange focal distance is one of the most important variables in a system camera, as lens seating errors of as little as 0.01 mm will manifest themselves critically on the imaging plane and focus will not match the lens marks. There are adapters to fix this, but they use a few lenses in them that result in images that are not as sharp.  So, the EOS M has a flange distance of only 18mm and there is no mirror to interfere. With the shorter flange distance, almost any lens can be adapted to the M with only a spacer set to the right distance. This opens a whole world of new options and I have to say that you can get many of these lenses for quite a bargain as well. I have a 28mm f2.8 m42 mount lens that I only paid $5 for!

Canon EOS M with 50/1.4, 135/2, 28/2.8 and the two autofocus system lense: canon 22/2 and 11-22 zoom

Canon EOS M with 50/1.4, 135/2, 28/2.8 and the two autofocus system lense: canon 22/2 and 11-22 zoom

There is a small catch, though. There is always a catch. These older lenses will only work manually. Manual focus, and manual aperture; you can, however, put the camera on Aperture Priority, and it will set the shutter speed and iso. Manual Focus with the M is not that hard, and I have put magic lantern on the camera, which makes focusing even easier. All you need to get started is a simple adapter. There are quite a few companies out there making them, I got mine from fotodiox. There are a ton of people on Ebay selling them. Buyer beware, the tolerances for the width of the adapter must be very accurate to work effectively.

You might think that older lenses would not have very good optical quality. Here are some samples made with a Auto Chinon 135/2.

 

 

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Back to school. Caitlyn’s Portrait. Canon EOS M – Chinon 135/2 set to f5.6 with an off camera flash providing fill.

This is 100% crop of the above image. You can see that the lens is impressively sharp.

This is 100% crop of the above image. You can see that the lens is impressively sharp.

Our new puppy, EOS M with 50/1.4 at f1.4

Our new puppy, EOS M with 50/1.4 at f1.4

 

 

 

There are some really great lenses out there, from macro to tilt-shift,

2 Comments

  1. Great article on the M body and lens. I’ve been thinking about adding one to my gear bag mainly for street photography. Folks react to the big 5DMKII’s with the loud shutter noise. With the M body it would be shooting like a Ninja.

    When I get a mirrorless, I might even hit you up for some advice on which lens to experiment with.

    Reply
    • is really is a great little camera for the price, as long as you are not trying to make it do something it is just not meant for. You are not going to photograph wildlife/sports with this rig. but for a walk around camera or trail camera, and landscape work it really is a gem – as long as you have the right lenses.

      Reply

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