Please keep the format of all links the same. If you have an idea for categorisation, please leave it on the talk page -- I'm stumped as to a good one.
- lipas.uwasa.fi/~f76998/video/conversion - Advanced information on the origins of aspect ratios and resolutions in use today
- www.mir.com/DMG/aspect.html - Advanced information on Pixel Aspect Ratios (PAR)
- www.seemoredigital.net - Easy to understand descriptions of miscellaneous intermediate topics. Hosted on a home connection, often down.