I have two SLR bodies, Ricoh XR-1s and Carena CX-300, and I've noticed Ricoh's strange behavior. While Carena measures more or less OK and simply loses the plot in low light (1EV error at most under normal conditions, completely unreliable below EV5 @ 50 asa, something to be expected), Ricoh does something odd: with Pentax-M 50/1.7 it constantly underexposes by 1 EV, and with other lenses it's accurate. This behavior is repeatable - every time my 50/1.7 goes on, the meter would underexpose an image by~1EV. I've tested it as well, as possible: flat surfaces, evenly lit. I've compared it with an exposure meter that always worked well - not that it does matter... I've changed ISO and lighting conditions, the lenses was changed many times per body during these tests. Same lens works OK with the other body. Any thoughts? Or is it me being wrong somehow?