Special Features:

115 volts; utilize spherical projection to provide direct registration of absolute target brightness of 31.5 asb and sphere luminosity of 1000 asb on a 30 cm radius projection hemisphere surface; spring-balanced, center posted table, with precise balance for instrument weight; contains a telescope with magnification not less than 1.85x; adjustable target size of 64, 16, 4, 1/4 and 1/16 sq mm with three built-in gray filters having relative light intensity levels ranged from 0.0315 to 1.00; three filter caps attachment with red, green and blue color each; chin adjustment range: vertically-in excess of 50 mm laterally-in excess of 80 mm

Properties:

An apparatus for determining the extent of the peripheral visual field on a curved surface.