TRIZ Principle No. 26

Instead of an unavailable, expensive, fragile object, use simpler and inexpensive copies.
  • Virtual reality via computer instead of an expensive vacation
  • Listen to an audio tape instead of attending a seminar.

Replace an object, or process with optical copies.
  • Do surveying from space photographs instead of on the ground.
  • Measure an object by measuring the photograph.
  • Make sonograms to evaluate the health of a fetus, instead of risking damage by direct testing.

If visible optical copies are already used, move to infrared or ultraviolet copies.
  • Make images in infrared to detect heat sources, such as diseases in crops, or intruders in a security system.