One of my students picked up a used Ricoh SR-Solar 35mm SLR. I searched the net and found references to the XR-Solar, but not to the SR. The camera I saw (SR) had a fixed lens while the XR can interchange K-mount lenses. I could not seem to get the solar powered meter to work so I advised my student to return the camera to the used camera store where she bought it. I'm just curious about the line of Ricoh solar powered cameras. Thanks. Celtfire