BS 4995:1973

This standard BS 4995:1973 Recommendations for measurement of the veiling glare index of lenses and optical systems is classified in these ICS categories:

• 37.020 Optical equipment

This British Standard adopts veiling glare index (bright field) (VGI) as a measure of the veiling glare characteristics of an optical system. Laboratory techniques for measuring VGI are described in general terms and recommendations are made regarding the performance of the main sub-units of the equipment.

Standard methods of specifying conditions of test and of expressing the results are given, while to assist in the intercomparison of VGI figures, four standard test conditions are specified. It is also the purpose of this standard to give guide lines for the operation of VGI measuring equipment such that accurate results may be achieved.

Laboratory techniques for measuring VGI are described in general terms and recommendations are made regarding the performance of the main subunits of the equipment. Standard methods of specifying conditions of test and of expressing the results. Gives guidelines for the operation of VGI measuring equipment to facilitate the obtaining of accurate results.