You must first decide on a standard image size for your images. So you have a consistent look for all of your pages. UAA has decided that all images should use the 3x2 aspect ratio.  This is the typical aspect ratio for most digital cameras used today. You can preview the below images by clicking the individual image size links.

3x2 Aspect Ratio Examples

2x3 Aspect Ratio Examples

Image Size on the page examples

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horizontal placeholder image medium

horizontal placeholder image small

vertical placeholder image large

vertical placeholder image medium

vertical placeholder image small