OLAC Best Practice for aspect ratio

Record when readily available for video recordings and when this information is found in the manifestation.

Cataloger's judgment. Optionally record with aspect ratio designation in a note. Do not combine aspect ratio with the equipment or system requirement note.

Record only when a formal aspect ratio is found on the manifestation. If uncertain whether it is accurate, do not record a structured description, but optionally record as a quoted note with source of information. If the aspect ratio is not stated as a numerical ratio in standard format with a denominator of 1, calculate the aspect ratio when it is ascertainable.