New adapter to use Contax 645 lenses on Nikon or Canon!

[lowep]

If I were to use the 210mm Contax 645 f4 lens with this adapter on a full frame Canon DSLR like the 5Dc the focal length would be the same ie 210mm (about 135mm 35mm equivalent), right?

Does that mean with the Contax 645 210mm lens on the Canon I would get an image covering the same area and coming just as close to the subject as with a 135mm Canon lens or a 210mm Canon lens? 

[alan_b]

If I were to use the 210mm Contax 645 f4 lens with this adapter on a full frame Canon DSLR like the 5Dc the focal length would be the same ie 210mm (about 135mm 35mm equivalent), right?

Does that mean with the Contax 645 210mm lens on the Canon I would get an image covering the same area and coming just as close to the subject as with a 135mm Canon lens or a 210mm Canon lens? 

Same as a Canon 210mm lens.

You'll just be illuminating your mirror box more with the Contax lens 

[lowep]

Thanks a lot Alan for the useful reply that helps me understand what would happen if I were to use this adapter to mount a Contax 645 lens on a Canikony 35mm ff (full frame) body

My understanding so far is this means:
210mm MF 645 lens on 645 body = 210mm (about the same angle of view as 135mm on 35mm ff camera)
210mm MF 645 lens on 35mm ff body = 210mm (same angle of view as 210mm 35mm lens on 35mm ff camera)

right?

does this also mean:
210mm 645 lens + MF 1.4x converter on 645 body = 300mm on 645 body (same angle of view as 180mm on 35mm ff camera)?
210mm 645 lens + MF 1.4x converter on 35mm film body = 300mm on 35mm body (same angle of view as 300mm on 35mm ff camera)?

this brings me to (yet) another question:
When mounting a 645 lens plus a teleconverter on a 35mm ff body via an adapter what if any difference in terms of functionality or image quality would there be if the teleconverter was designed for the 35mm body (eg Canon 1.4x, 2x) or the 645 lens (eg Contax 1.4)??