Originally posted by Kevin B123 I set the aperture on the lens, not the body and the camera makes a correct exposure, whether I have set f1.7 or f16.
The exposure time varies, it is showing Av on the back the camera even in P or TV mode.
With a manual lens like the M 50/1.7, putting the camera to any of the auto modes will cause the camera to revert to Av.
In Av mode the camera will give a correct exposure by adjusting shutter speed, but always uses wide open aperture. It wont stop down the lens even if you put the aperture ring to f22.
The only way to have the lens stop down is to use M mode. This has been the way all Pentax DSLRs worked up until the K-3 III. That model operates differently.