Mirror lenses, also known as reflex lenses are easily used in aperture priority.
The Canon FD 500mm reflex lens is a manual focus telephoto lens that is used by many nature and landscape photographers who may not need the speed of an autofocus lens. While autofocus cameras and lenses have been around since the late 1990s, there are still many manual focus lenses and cameras that are available on the used market. Using this lens in the camera's aperture priority mode is good since the aperture is fixed at f8.
Instructions
1. Attach your camera to the lens by lining up the red dot on the camera mounting ring to the red dot on the outside of the lens barrel close to the rear of the lens.
2. Connect the lens to a tripod or mono-pod for stabilization. While this lens is not very heavy--it is considerably lighter than autofocus lenses since there are no internal motors--you should still use a tripod or monopod since the field of view is very narrow and any camera shake will appear in your photos.
3. Set the camera to "Av" which stands for aperture value. Depending on the camera you are using the steps may be different from camera to camera. On manual film Canon cameras like the F-1, A-1, you simply turn the shutter speed dial to "A" and the camera will select the correct shutter speed. If you are using a Canon T-90, press the "Mode" button on the top left of the camera, and turn the wheel just behind the shutter release to you see "Av" in the screen.
Tags: aperture priority, Canon 500mm, manual focus, shutter speed, this lens