How to mount a projection lens, front adapter can be changed, as well as rear (can be basically any camera).
Works from infinity (depending on lens back focal length) to very closeup. Setscrews allow to calibrate the infinity position.
Lens --> Lens Adapter to M65 --> M65 to M42 Helicoid --> M42 to Camera mount Adapter
It is not a slim elegant and lightweight solution, but the benefits are:
1) no lens modification needed
2) very durable
3) non rotating front
4) accepts a variety of lens types and lens diameters
5) allows a variety of camera mounts
6) needs only about 15mm net optical length (plus camera register) for lens diameter 62.5mm or smaller
7) safes money and time for not having to go to the gym, as it is quite heavy :-)
The design is basically made to accept 35mm film russian projection lenses with a standard 62.5mm diameter.
Smaller ones (52.5mm etc.) are possible using a different front plate, also some larger ones, but infinity focus
may often not be reached using the latter, as such lenses cannot dive into the helicoid.
The M65 helicoid is made in China and may be found on ebay.
Those two adapter rings (front and back) are made by rafcamera.com based on my design.
The front one has three hex nut setscrews which hold the lens in place and allows to adjust infinity focus (only if the lens has enough back focal length)
Rafcamera offers several camera adapter plates for the rear one incl. Nikon-F.
Orders may be done directly through their site or through amazon.com
http://www.amazon.com/s/ref=nb_sb_noss?url=search-alias%3Dphoto&field-keywords=rafcamera+M65&rh=i%3Aphoto%2Ck%3Arafcamera+M65(I have no connections with them except that I'm a happy customer...)
[my name is on the rings was a curtesy of rafcamera and is a non standard feature]
