Adapter rings for Canon EOS (digital)

What to do with all these lenses, while silver photography is dying? Adapt them on a digital camera!
You can find on the Internet (eBay, still!) adapter rings allowing to use some optics from a mark to another.
The light metering is done with real opening, when the body allows it. Here are rings to adapt M42 screw-mount to Canon EOS, it works very well with the 400D and the 5D, most of the images of this site are made with it. For Canon EOS you have better use rings with electric couplings, during their use, the EOS bips for telling you that you have found the focus point! I even found someone who programs the chips according to the lens you wish to use. I ordered for rings for the Peleng and the Zenitar, it improves the light metering!

My first trial: simple ring (M42 -> Canon EOS) The light metering is done at real aperture, no help from the autofocus. With the EOS 1000FN (argentic), the light metering is wrong, you must use a ring with identification chip.

Second trial: another with an "identification chip". The chip you usually can find tells the camera that the lens is a 50mm. It seems that the light metering uses the focal length in the calculation, so the images made with the Peleng (8mm) are under-exposed.
I since bought black rings (to avoid problems of "flare"), with a flange to press the iris control finger of "coupled" lenses, and equipped with "chips" programmed for various focal lengths. With the Peleng 8mm, the results are better using the "chip" programmed for it.

A Pentax-K -> Canon Eos ring: the "identification chip" didn't come with it, I found it on the Internet; it is fixed with double-side tape. With this ring, the iris-control lever of the lenses scraps the electrical contacts of the camera during assembling (you can cheat by settling the lens in the opposite direction of normal). The Volna 1.8/50mm of the Almaz does not fit on this ring, I then bought a newer one: to prevent the camera's contacts from being damaged, the lenses are adapted shifted by 1/4 turn. Consequence: the iris control lever is on the path of the mirror of the EOS 5D, which may be broken! This ring is only compatible with APS-C sensor cameras.