Christie 900-300349-XX Short Fixed Ultra-Short-Throw Lens Guide: Compatible with 4K13-HS / 4K22-HS

Genuine Christie Lens 900-300349-XX Short Fixed is an OEM optical accessory for Christie professional projectors. It is an ultra-short-throw (Ultra Short Throw) lens with a throw ratio of 0.38:1. The factory compatibility list covers two projector models; before installation, simply verify the projector model and panel size—no adapter ring is needed. The value of an OEM lens lies not in the extra figures on a specification sheet, but in the fact that it is calibrated at the factory to the optical path and mount of that projector series. Once installed, the image circle, edge illumination, and focusing travel are all at their design values, so keystone correction is unnecessary to compensate for image quality.

1. Lens Specifications

The above specifications are subject to the OEM specifications. For mechanical dimensions, flange distance, and mount type not shown in the specifications table, please verify them with us based on the projector model. Ordering based solely on a similar model carries the risk that the lens will not fit.

2. Calculating Installation Distance from Throw Ratio

The throw ratio is the ratio of installation distance to image width. This OEM lens is fixed focus (0.38:1), so the installation distance varies linearly with image size, with no adjustment margin. It must be measured accurately before installation.

The above figures represent the clear distance from the front of the lens to the screen and do not include cooling clearance or space for cable connections at the rear of the projector. They are calculated for a 16:10 image; actual installation should follow on-site measurements and the manufacturer's manual.

3. Compatible Models (2 Models)

The table below is taken from the OEM compatibility list. Brightness and resolution are completed from the model database; where the data is unavailable, “—” is shown, with no assumptions made.

For models not included in the list, please send us photos of the projector nameplate and the existing lens so we can verify compatibility. Platforms of the same generation often share the same mount, but ordering based on a similar model is not worth the risk.

Throw Ratios by Projector Series

The same 900-300349-XX Short Fixed is used in the following series, but the nominal throw ratio differs. Select the value based on the series of the actual projector.

4. Three Checks Before Replacement

• Confirm the projector imaging chip and resolution. OEM lenses are designed for a specific panel size. When the panel specifications differ, the image circle cannot provide full coverage, resulting in vignetting or edge light loss after installation.
• Calculate the installation distance first. This lens has a nominal throw ratio of 0.38:1. Use the table in Section 2 to calculate the distance for your installation site. A fixed-focus lens has no adjustment margin, and even a zoom lens should allow an additional 10–20 cm at both ends.
• Verify the mount and locking mechanism. OEM lenses are calibrated to the mount used on that projector series. After installation, you must hear the lens click into the locked position. A skewed image or soft edges usually mean that the lens is not fully locked, rather than that the lens itself is defective.

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