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Is the Measurement of Front-Projection Characteristics an Impossible Task



Paul A. Boynton, Edward F. Kelley


Specifications of electronic projection displays, such as contrast ratio, are often based on measurements made in ideal darkroom conditions. However, not everyone has access to such a facility. Stray light from other sources in the room (both direct and reflected off surfaces, such as walls and tables) as well as back-reflections, contribute to the measured value and give an inaccurate measurement of the projector's light output. So how can we verify that the projector that we have purchased is operating according to its specifications?
Information Display


display measurement, projection displays, projection mask, reflections, stray light


Boynton, P. and Kelley, E. (1998), Is the Measurement of Front-Projection Characteristics an Impossible Task, Information Display, [online], (Accessed April 17, 2024)
Created November 30, 1998, Updated October 12, 2021