Canon PowerShot A40 PowerShot A40/A30 Camera User Guide - Page 75

Using the Focus Lock The following types of subject may not be suited to autofocus photography. Use the focus lock in these situations. ¡ Subjects with extremely low contrast to the surroundings ¡ Subjects with extremely bright objects at the center of the composition ¡ Subjects that are mo ving quickly ¡ Subjects through glass Try to shoot as close to the glass as possib le to reduce the chances of light reflecting bac k off the glass. Focus Lock Method 1 1 Aim the camera so that a subject at the same focal distance as the main subject is centered in the brackets in the optical viewfinder or LCD monitor. 2 Press and hold the shutter button halfway, and wait until the camera beeps twice. Without releasing your finger, re-aim the camera to compose the shot as desired and press the shutter button all the way. 71