I'm borrowing my girlfriend Dad's Canon AE-1 this weekend, He let me borrow the 50mm f/1.8, and a 80-200 f/3.4-4. I know it has a program mode.. I am wondering, I want to be able to shoot controlling the Aperture, but NOT the Shutter speed. Basically, I wanna be in Aperture priority. Is this possible? Oh, how is this 50mm f/1.8?