How to change the size of your canvas for cool framing ratios to change the composition
Some digital cameras have the option to change the image’s aspect ratio.
Ratios include 4:3, 16:9 and 3:2. To try out these variations in Photoshop ,the Crop tool has these already set up.
In Photoshop CS6, untick the box ‘Delete Cropped Pixels’ box and Ctrl/right-click over the image to view all available ratios.