Canon A4050 IS - Manual (Page 92)

Image Brightness (Exposure Compensation)
92
z You can also lock the exposure by pressing
and holding the shutter button halfway, and
then touching the bottom of the screen
(inside the frame shown at left).
z To unlock AE, release the shutter button and
touch the screen again. In this case,
& is no
longer displayed.
Adjust the metering method (how brightness is measured) to suit shooting
conditions as follows.
z Press the n button, choose [Light
Metering] on the 4 tab, and then choose the
desired option (p. 51).
X The option you configured is now displayed.
Using the Touch-Screen Panel
A3400 IS
Changing the Metering Method
Still Images
Evaluative
For typical shooting conditions, including backlit shots.
Automatically adjusts exposure to match the shooting conditions.
Center Weigh.
Determines the average brightness of light across the entire image
area, calculated by treating brightness in the central area as more
important.
Spot
Metering restricted to within the (Spot AE Point frame),
displayed in the center of the screen.