I just picked up a Contax 159mm with 50mm f/1.7 MM and 135mm f/2.8 MM T* lenses. Reading the instruction manual, it appears that aperture and autoexposure information should be at the bottom of the viewfinder when I press the shutter half way, but there is nothing illuminating at the bottom. This occurs with both lenses. Is there a way of discriminating MM from non-MM lenses? I see no conspicuous marks on either lens. I don't know if the problem is the camera or the lenses. TIA.