I have a CE and CM3, the CE had a electronic shutter and aperture preferred exposure with single pin M42 lens. When the shutter is fired as the lens closes down the meter read the light and sets the shutter speed. The CM is all mechanical with a 3 diodes for the meter, red and green, not in the viewfinder on the outside edge of the read viewfinder, just visible in my right eye. Both take a 2 FPS motor drive. My third is the CE7, KA mount. The top plate is large, it is a pressure switch to select manual, program or aperture preferred exposure. Built in motor drive, F stop read out in the viewfinder, integrated motor drive, uses AA batteries. I use it with a M42 to K mount adaptor in A mode. Last is now my favorite point and shoot, the 35F MA, Infrafocus AF. It has a scale in the viewfinder that give a sense of where the AF is locked on. As a first generation it is not DX coded so I can fool the meter if I'm shooting in a back lite situation. Takes 46mm filter and lens hood. The lens is 35mm 2.8, I assume a 4 element. I have not found one with a working flash, likely faulty capacitor.