High Res is a Tumblr theme designed especially for large images and video, originally developed by jstn for Noah Kalina’s Pictures That Look Like This.
Nearly every aspect is adjustable. It can be used out of the box, or as a minimal base for further customization with CSS or the built-in appearance settings. It features smooth infinite scrolling, precise control over image and video sizes, selectable colors, language localization, the ability to show or hide every individual element (date, tags, note count, etc.) and much more. High Res is available in the theme garden now for $19.