Images(2)

light viewer

Datecirca 1959

Inventory Number2004-1-0284

ClassificationOptics Apparatus

Subject

Maker Edwin H. Land 1909 - 1991

Maker General Electric Company 1892-present

Cultural Region

Place of Origin

Dimensions23.5 × 19 × 24 cm (9 1/4 × 7 1/2 × 9 7/16 in.)

Material

DescriptionA trapezoid shaped box in which is found three light sources and two mirrors positioned at 45° each. Each light has its own electric cord. On one of the box's sides there is a window to examine the superposition of images produced by this apparatus.

In Collection(s)

Signedon light bulbs: GE

Curatorial RemarksThis apparatus is similar to a drawing from one of Land's 1959 articles on color vision. Though similar, it cannot be this one since, as the description goes: "In order to make the demonstration more effective we built a pair of viewers (Fig. 4), each employing a large sodium-vapor street light as one of the illuminants. In each viewer the long and short records are placed ar right angles to one another and the images are superposed, as they are in the dual monochromator, by means of a semi-mirror at 45°" (p. 641 and 644). The apparatus here was probably built for similar studies on color vision. Perhaps later, since in this apparatus we find three lights shining on two semi-mirrors. Reproduced, slightly modified, in Land, "Experiments in Color Vision," <i>Scientific American</i> 200 (1959): 84-99.

FunctionUsed to illuminate with different types of light (sodium, tungsten, etc.) glass plates in order to study color vision. Land used this instrument for his Retinex theory.

ProvenanceThis object belonged to Edwin H. Land and came from the Rowland Institute, Harvard University. Gift of the Edwin H. Land Family.