Christie 121-118101-XX Ultra Short Zoom Standard-Throw Lens for 13 Models

Christie Original Lens 121-118101-XX Ultra Short Zoom is an OEM optical accessory for Christie engineering projectors. It is a standard-throw lens (Standard Throw) with a throw ratio of 0.78-0.97:1. The OEM compatibility list covers 13 projector models. Before installation, simply verify the lens against the projector model and panel size; no adapter rings are needed. The value of an OEM lens lies not in the additional figures in its specification sheet, but in the fact that it is calibrated at the factory to the optical path and mount of the relevant projector series: once installed, the image circle, edge illumination, and focusing travel all meet their design specifications, eliminating the need to compensate for image quality with keystone correction.

I. Lens Specifications

Brand	Christie（Christie）
Lens Model	121-118101-XX Ultra Short Zoom
Throw Ratio	0.78-0.97:1
Product Type	Standard-throw lens (Standard Throw)
Compatible Models	13 models
Warranty	12 months; damage not caused by the user is eligible for after-sales service, based on the date shown on the shipping documents

The above specifications are subject to the OEM specifications. For mechanical dimensions, flange distance, and mount type not listed in the specification table, please contact us with the projector model for verification. Ordering directly on the basis of a similar model carries the risk that the lens will not fit.

II. Converting Throw Ratio to Installation Distance

A throw ratio is the ratio of the installation distance to the image width. This OEM lens is a zoom lens (0.78-0.97:1), so a given image size corresponds to a range of installation distances. The lens can be focused when installed anywhere within this range.

Image Size	Image Width	Required Installation Distance
100 inches	2.15 m	approx. 1.68 – 2.09 m
120 inches	2.58 m	approx. 2.01 – 2.50 m
150 inches	3.22 m	approx. 2.52 – 3.13 m
200 inches	4.30 m	approx. 3.35 – 4.17 m

The distances above are clear distances from the front face of the lens to the screen and do not include clearance for cooling and cable connections at the rear of the projector. The values are calculated for a 16:10 frame; actual values are subject to on-site measurements and the manufacturer's manual.

Image quality differs at the two ends of the zoom range. Toward the near end, the image is brighter and the edges are slightly softer; toward the far end, the edges are sharper and the image slightly dimmer. When the venue allows, it is recommended to use the middle of the range. After installation, first find the sharpest setting on the focus ring, then fine-tune the lens shift.

III. Compatible Models (13 Models)

The following table is taken from the OEM compatibility list. Brightness and resolution are populated from the model database; an em dash is shown where data is unavailable, and no values are estimated.

Model	Brightness	Resolution
DHD1052-Q	9500 lumens	1920x1080
DHD851-Q Black	—	—
DHD851-Q White	—	—
DHD951-Q	8200 lumens	1920x1080
DWU851-Q Black	—	—
DWU851-Q White	—	—
DWU951-Q	8500 lumens	1920x1200
DWX851-Q Black	—	—
DWX851-Q White	—	—
DWX951-Q	8500 lumens	1280x800
DWX951-Q White	8500 lumens	1280x800
DXG1051-Q	10400 lumens	1024x768
DXG1051-Q White	10400 lumens	1024x768

For models not on the list, please send us photos of the projector nameplate and the existing lens for verification. Platforms from the same generation often share a mount, but ordering based on a similar model name is not worth the risk.

Throw Ratios for Different Model Series

The nominal throw ratio differs among the following series when the same 121-118101-XX Ultra Short Zoom is installed. Select the value according to the series of the actual projector.

Model Series	Throw Ratio
—	0.78-0.97:1

IV. Three Checks Before Replacement

• Confirm the projector imaging chip and resolution. OEM lenses are designed for a specific panel size. If the panel specifications differ, the image circle cannot cover the full image, resulting in vignetting or light loss at the edges.
• Calculate the installation distance first. This lens has a rated throw ratio of 0.78-0.97:1. Use the table in Section II to calculate the distance for your installation site. A fixed-focus lens offers no adjustment margin, and even a zoom lens requires 10–20 cm of clearance at both ends of the range.
• Check the mount and locking mechanism. OEM lenses are calibrated to the mount of the corresponding projector series. You must hear a click confirming that the lens locks into place after installation. A skewed image or soft edges are usually caused by incomplete locking, rather than a problem with the lens itself.

If you are unsure, take one photo of the projector nameplate and one of the existing lens nameplate, then send them to us. Verification against the actual hardware is the safest approach.