1.1 This photographic practice determines the optical distortion and deviation of a line of sight through a simple transparent part, such as a commercial aircraft windshield or a cabin window. This practice applies to essentially flat or nearly flat parts and may not be suitable for highly curved materials.

1.2 Test Method F801 addresses optical deviation (angluar deviation) and Test Method F2156 addresses optical distortion using grid line slope. These test methods should be used instead of Practice F733 whenever practical.

1.3 This standard does not purport to address the safety concerns associated with its use. It is the responsibility of the user of this standard to establish appropriate safety and health practices and determine the applicability of regulatory limitations prior to use.