Goniophotometry is a general procedure for evaluating the manner in which an object or a material geometrically distributes the unabsorbed portion of incident light, whether by reflection or by transmission.

Formerly under the jurisdiction of Committee E12 on Color and Appearance, this guide was withdrawn in June 2005 in accordance with section 10.5.3.1 of the Regulations Governing ASTM Technical Committees, which requires that standards shall be updated by the end of the eighth year since the last approval date.

1.1 Goniophotometry is a general procedure for evaluating the manner in which an object or a material geometrically distributes the unabsorbed portion of incident light, whether by reflection or by transmission.

1.2 The two former, essentially identical, Recommended Practices for Goniophotometry, E 166 for transmitted light and E 167 for reflected light, are now combined in this one practice.

1.3 This standard does not purport to address all of the safety concerns, if any, 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 .