How to focus using subjects with high contrast
27-Apr-2010
8200711900
Solution
There are cases where monotone subjects with low contrast cannot be brought into focus when using the AF function that is available in compact digital cameras. This occurs because subjects with fewer changes in color and shape are difficult to bring into focus with AF.
This section explains how to focus by putting a subject with high contrast in front of a hard-to-focus subject.
CAUTION
- In this section, [PowerShot A3100 IS] is used as an example to explain the operations. Depending on your model, the position of buttons, screen indications, and setting items may vary.
NOTE
- Change the camera settings before shooting. Set the [AF Frame] to [Center] or [Fixed frame] so that focus can be achieved easily. Please see below for how to set the [AF Frame] to [Center] or [Fixed frame].
1. Point the camera at the subject, and then press the <Shutter Button> halfway.
The subject cannot be brought into focus because it has low contrast.
If the camera cannot focus when you press the <shutter button> halfway, 
the [AF frame] will turn yellow.
the [AF frame] will turn yellow.2. Place an object with high contrast right in front of the subject.
A name card is used as an example here.
3. Move the [AF Frame] to the name card, and then press the <Shutter Button> halfway.
The [AF Frame] turns green, and focus is now achieved.
4. Remove the name card while holding down the <Shutter Button> halfway.
5. Press the <Shutter Button> fully for shooting.
REFERENCE
- For Focus Lock, please also see below.
- If the [AF Lock] is used to fix the focus, the focus position will remain fixed even if you release your finger from the <Shutter Button>. To set the [AF Lock], hold down the <Shutter Button> halfway, and then press the <left button> on the <Directional buttons>. The focus locks and (
) is displayed on the screen. To cancel the [AF Lock], press the <left button> on the <Directional buttons>.