Use a DVD as

This is a book about using a standard DVD or CD as a photography subject, and from a more complete description, how these these disks can be used as color temperature meters. I show that diffraction and lighting patterrns on a DVD disk differ significantly under LED, fluorescent, and tungsten lighting so that a photographer can easily distinguish what lighting source he/she is shooting under, without having to use an expensive color temperature meter. This simple technique can result in photographs taken under the correct lighting conditions, which may not be easily o repeated later.