General Electric GE GM-392 4.2:1 Light Valve Projector Lens Made in Japan

General Electric GE GM-392 4.2:1 Light Valve Projector Lens Made in Japan

This is a General Electric 4.2:1 Light Valve Projector Lens, model GM-392, manufactured in Japan for GE's Electronics Park facility in Syracuse, NY. The lens is a large-format barrel-style optic designed for use with GE light valve projection systems. We have multiple units available, each carrying a different model number as noted below.

Specifications & What's Included

• Brand: General Electric (GE)
• Model Numbers Available: GM-392, FM-181, FM-384, FM-110 (each unit has a different number)
• Zoom / Projection Ratio: 4.2 to 1 (4.2:1)
• Lens Type: Light Valve Projector Lens
• Country of Manufacture: Japan
• Manufacturer: General Electric, Electronics Park, Syracuse, NY, USA
• Lens barrel construction: cylindrical black housing with threaded front and rear mounts
• One lens cap included per unit (one lens cap is missing — only one cap present rather than two)

Applications

GE light valve projection systems were large-format, high-brightness projectors developed by General Electric from the 1950s through the 1980s, widely used in planetariums, large auditoriums, military briefing rooms, and industrial simulation and training facilities. The light valve technology used an oil-film optical modulator to produce extremely bright, high-contrast images on large screens — well before LCD and DLP projection became viable for large-venue use. A 4.2:1 ratio lens such as this was used to project images over a relatively long throw distance, suitable for wide venues or large screens. These lenses were precision-ground and manufactured in Japan to GE's specifications, and are now sought after by collectors, restorers, and institutions maintaining or replicating vintage GE projection systems. Replacement optics for GE light valve projectors are increasingly scarce, making surviving lenses like this of particular interest to those keeping these historic systems operational.