5:4 aspect ratio

The 1280 by 1024 panel was extremely common for a decade and it is the reason a lot of people met this ratio without knowing it. Its native shape is 5:4 at 1.25, but the operating systems and games of the era frequently assumed a 4:3 desktop at 1.333, so circles rendered as ovals and nobody could say why.

The other place it turns up is the 8 by 10 inch print, which is 5:4 exactly and is one of the most common frame sizes sold. That is the trap for anyone printing photographs: a 3:2 camera frame at 1.5 does not fit an 8 by 10, so every such print involves cropping roughly a sixth off the long side.

It is worth keeping distinct from 4:3, which it superficially resembles. The gap between 1.25 and 1.333 is about seven percent, which is small enough to look like a rendering artefact and large enough to be visible on a face, so mixing content authored for the two in one layout produces subtle distortion rather than an obvious error.

There is no 5:4 preset in the cropper, whose fixed ratios are 1:1, 4:3, 16:9, 3:2, 2:3 and 9:16. Enter 5 and 4 as a custom ratio, or work the height out from the width with the calculator first. Doing the arithmetic before the crop is worth the extra step here, because 5:4 is close enough to 4:3 that a mistake is easy to miss on screen.