The Christie 121-118101-XX is an ultra-short zoom lens engineered for projectors that require extreme placement flexibility in the most space-constrained installations. Featuring a remarkably low zoom ratio of 0.8-1.0:1 (with a 1.25x overall magnification factor), this lens provides minimal size adjustment, effectively functioning as a near-fixed focal length lens with just a slight margin for fine-tuning. Its defining characteristic is an ultra-short throw ratio, allowing the projector to be positioned exceptionally close to the screen—often just a fraction of the screen's width away. This capability is critical for applications like rear-projection boxes with severely limited depth, interactive displays where the projector must be mounted directly above the surface, or architectural installations where hiding the projector is paramount.

This lens is designed to maintain optical integrity when projecting from such an acute angle, minimizing geometric distortion (like keystoning) and preserving edge-to-edge focus and brightness. The near-fixed design with a tiny zoom range typically allows for a large maximum aperture, maximizing light transmission to ensure the projector's brightness is not compromised. Built into a precision metal housing, it includes manual controls for its limited zoom and focus adjustments. For system integrators designing immersive environments, command centers, or unique retail displays, the Christie 121-118101-XX is a specialized solution that enables large, seamless images from projector placements that would be impossible with standard lenses, turning spatial limitations into creative opportunities.