On 10/8/05, Gonz, discombobulated, unleashed: >Now is there an opposite version, or would that be problematic for the >optics, being that the canon glass has a larger diameter?
It's not the diameter that's crucial here, it's the register distance. That is, the distance from the mating surface of the lens - the flange surface - to the film plane (or sensor plane. On a Canon it's 44mm and on a Pentax it's 45.46mm. This means that to put a Pentax lens on a Canon body, you need to move the lens 1.46mm further away from the body. Easy, as an M42/EOS adapter has just that - 1.46mm extra space to do that (M42 register distance is 45.46mm as well) - you following this? To do it the other way around, you'd need to get the Canon lens 1.46mm closer to the film plane. So how could you do that? You could mill 1.46mm off the lens (not possible) or off the body (impractical but probably possible except it would screw up that body for normal Canon lenses). Or you use an adapter with optics to compensate. AFAIK, none are produced. HTH Cheers, Cotty ___/\__ || (O) | People, Places, Pastiche ||=====| http://www.cottysnaps.com _____________________________
