Christie 121-120104-01 Standard Zoom Long-Throw Lens for 11 Models

Christie Original Lens 121-120104-01 Standard Zoom is a factory-original optical accessory for Christie professional projectors. It is a long-throw (Long Throw) lens with a throw ratio of 1.65-2.47:1. The official compatibility list covers 11 models; before installation, simply verify the projector model and panel size, with no need to make do with adapter rings. The value of a factory-original lens lies not in the extra figures in the specifications, but in the fact that it is factory-calibrated to the optical path and lens mount of that projector series. Once fitted, the image circle, edge illumination, and focusing travel all meet the design values, so there is no need to use keystone correction to compensate for image quality.

I. Lens Specifications

Brand	Christie (Christie)
Lens Model	121-120104-01 Standard Zoom
Throw Ratio	1.65-2.47:1
Product Type	Long-throw lens (Long Throw)
Compatible Models	11 models
Warranty	12 months; after-sales service applies to damage not caused by improper handling, subject to the date on the shipping documents

The above specifications are subject to the manufacturer's official specifications. For mechanical dimensions, flange distance, and mount type not listed above, contact us with the projector model for verification. Ordering based solely on a similar model carries the risk that the lens will not fit.

II. Converting Throw Ratio into Installation Distance

The throw ratio is the ratio of installation distance to image width. This factory-original lens is a zoom lens (1.65-2.47:1), so a given image size corresponds to a range of installation distances. The lens can focus at any point within that range when installed.

Image Size	Image Width	Required Installation Distance
100 inches	2.15 m	Approx. 3.55 – 5.31 m
120 inches	2.58 m	Approx. 4.26 – 6.37 m
150 inches	3.22 m	Approx. 5.32 – 7.97 m
200 inches	4.30 m	Approx. 7.09 – 10.62 m

These figures represent the clear distance from the front surface of the lens to the screen and do not account for rear housing ventilation and cabling clearance. They are calculated for a 16:10 image; actual values are subject to on-site measurements and the manufacturer's manual.

Image quality differs at the two ends of the zoom range: the image is brighter and the edges slightly softer near the short-throw end, while the edges are sharper and brightness is slightly lower near the long-throw end. Where venue conditions allow, 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 (11 Models)

The table below is taken from the manufacturer's official compatibility list. Brightness and resolution are populated from the model database; entries that cannot be found are marked “—” and are not 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

To check whether a model not on the list is compatible, send us photos of the projector nameplate and existing lens. Projector platforms from the same generation often share the same lens mount, but the risk of ordering based on a similar model is not worth taking.

Throw Ratios for Different Model Series

The rated throw ratio of the same 121-120104-01 Standard Zoom lens varies by projector series. Select the value based on the series of the actual projector.

Model Series	Throw Ratio
—	1.65-2.47:1

IV. Three Checks Before Replacement

• Confirm the projector chipset and resolution. Factory-original lenses are designed for specific panel sizes. If the panel specifications differ, the image circle cannot cover the full image, resulting in vignetting or loss of illumination at the edges.
• Calculate the installation distance first. This lens has a rated throw ratio of 1.65-2.47:1. Apply the table in Section II to your venue dimensions. A fixed-focus lens offers no adjustment range, while a zoom lens still requires 10–20 cm of margin at both ends.
• Verify the mount and locking mechanism. Factory-original lenses are calibrated to the mount of the corresponding projector series. After installation, you must hear the lock engage fully. A skewed image or soft edges are usually caused by incomplete locking, rather than a problem with the lens itself.

If you are unsure, send us one photo each of the projector nameplate and the existing lens nameplate. Verification against the actual equipment is the most reliable approach.