Solution
1. Press the <Power> button on the camera.
2. Press the <FUNC./SET> (

) button.
3. The following screen appears.

Operate the <directional buttons> up or down to select [Still Image Aspect Ratio].

Operate the <directional buttons> right or left to select an aspect ratio of your choice, then press the <FUNC./SET> (

) button.
When the following shooting modes are selected, the aspect ratio cannot be changed, or limited aspect ratios are available.
... Cannot be set
... [4:3] or [16:9] can be selected
... Shooting mode is not available on this model
Model | Shooting Modes |
 | , , , , , , , , , ,  |  |
PowerShot S110 |  |  |  |
PowerShot SX50 HS |  |  |  |
PowerShot G15 |  |  |  |