Canon DSLR camera with telephoto lens.
The Canon 20D digital SLR camera is a "prosumer" camera aimed at the advanced amateur to professional photographer. It allows the photographer to customize many functions that aren't always available in consumer digital cameras. One of those features is the focus lock, which lets the photographer lock the focus on a subject and recompose the frame while keeping the subject still in focus.
Instructions
1. Turn on the camera. Press the menu button, and spin the big dial on the right side of the LCD to select the custom function. It is the orange wrench selection near the bottom of the menu. Once you select, it press "Set."
2. Spin the big dial until you select custom function 04. Press the "Set" button to select that function.
3. Select number 2 under custom function 04. Press "Set" to save the change. This custom function setting causes "*" button to lock the focus of the camera when it is pressed.
4. Aim the camera at the subject you want to take a picture of, and adjust the focus. Halfway press down on the shutter button, and press the "*" button to lock the focus on the subject. You can now recompose the picture and keep the subject in focus.
5. Completely press down on the shutter button to take a picture using the focus lock.
Tags: custom function, lock focus, button lock, button lock focus, custom function Press, down shutter, down shutter button