Story time.. For a while, I've been in love with manual lenses, I actually own some of them, but when I saw the article on Hispan's photoblog (hispan.hu) about mounting an RO-109-1A projector lens to his camera, my first thought was... I NEED THIS! So I did a little bit of research, and found the Pentacon AV 80/2.8 which has been mounted on Canon EF successfully by others. So I thought, it would be a good idea to start with that.
Step 1: What You Will Need..
-Pentacon AV 80/2.8 (of course)
-Helios 44-2 focus mechanism
-smallest m42 extension tube
Step 2: About the Lens Itself
I bought it online for about 8000HUF (nearly 32 $) , but I'm sure you can find one on eBay for even less.
Since this is a projector lens, it doesn't have aperture blades, so its a fix f/2.8.
Step 3: Get Started
First of all, you have to cut off the outer plastic tube of the lens. You should cut off as much as you can, without damaging the optical elements. After it, sand the cut to get a smooth surface. If you do it right, you should get something like shown in the picture.
After that put some rubber rings on the thinner part of the lens, so you can secure it into the focus mechanism.
Step 4: Preparing the Focus Mechanism
I found the best option for the focusing is to use the focus mechanism of a Helios 44-2, because you can easily disassemble the Lens, and put in the new optics.
So get the optical elements of the Helios out of the focus mechanism. In order to do that, you should just turn it anti-clockwise until it just falls out. Then you have your mechanism ready to get it's new optics. :)
Step 5: If You Want Focus....
If you want to have focus (and I bet you want it), then you should screw on the thinnest extension tube to the mount of the mechanism. You can get an m42 extension tube set on eBay for a couple of bucks, so I think it won't be a problem.
Step 6: Put Everything Together
Now it's time to put everything together and finish our project.
First, you should put the Pentacon lens in the right place of the focus mechanism (yes, it's the big round hole in the middle). After that it's time to screw on the m42-Canon EOS adapter, and when you are done, the last thing to do, is to try it out.
Step 7: Some Test Pictures
It's a projector lens, so it doesn't have aperture blades.. (I know, I already told that, but you should really be aware of that), so you should play with the ISO and the shutter speed to get the right amount of light to the sensor.
In conclusion, it's not a sharp lens, but it has a really unique style and an outstanding frame of mind.
Feel free to comment your pictures made with it, I'd be really interested in your artwork :)