Giles-Archer Colour Perception Unit

A simple, defunct Lantern Test, where a light bulb is shined through a rotary disc carrying six filters (dark red, red, yellow, signal green (cyan), green and clear). A slider behind the disc allows for selection of variable-sized apertures. The subject is sat at 6m away from the lantern in a completely dark room and must be dark adapted before the test. This test was particularly popular with the RAF (UK), which commissioned its own ‘aviation’ model with more colors (Jordinson/Minshall 1959).