WK281 0.38:1 Projector Lens, Christie 4K1000-KS/4K1400-KS/4K2100-JS/4K1600-JS/DWU2400-JS/DWU1800-JS

WK281 is a short-throw lens for 0.8-inch panels in Christie projectors, featuring a 0.38:1 throw ratio and lens shift. It is compatible with 6 models in 1 model series. This guide brings together the lens specifications, installation distances, model compatibility list, and key replacement considerations.

I. Lens Specifications

Lens shift is the key differentiator of this lens. Its ±17.3% horizontal and ±10.9% vertical shift range allows the projector to be installed off the screen centerline and the image repositioned using lens shift, without relying on keystone correction. Keystone correction comes at a cost—each adjustment step sacrifices some effective pixels and can blur text edges. In professional installations, never use keystone correction when lens shift can resolve the issue; this is the baseline for image quality.

II. Calculating Installation Distance from Throw Ratio

The throw ratio is the ratio of installation distance to image width. This lens has a fixed focal length (0.38:1), so the installation distance changes linearly with image size, leaving no room for adjustment. Accurate measurements are essential before installation.

The distances above are the clear distances from the front of the lens to the screen and do not include space for rear housing ventilation or cabling. Values are calculated for a 16:10 image; actual installation should follow on-site measurements and the manual.

III. Compatible Models (6 Models, Christie)

The table below is arranged by model production date, from newest to oldest, and lists each model’s resolution, brightness, and factory-lens zoom ratio for quick selection according to project requirements.

Common Features of These Models

The factory-installed standard lenses for these 6 models mostly have throw ratios listed as Depends on the lens. The 0.38:1 ratio of the model featured here effectively adjusts the focal length, enabling a different image size from the same projection distance—the direct reason for replacing the lens. It also retains the full lens-shift capability, so the image can still be aligned after the focal length is adjusted.

IV. Three Things to Confirm Before Replacement

• The panel and resolution must match. This model supports 0.80-inch panels. Projectors with a different panel size or resolution can produce somewhat different projection performance, so checking the chassis nameplate before installation is the safest approach.
• Check the interface and locking mechanism. Interface compatibility is generally good within the same platform generation, but the position of the locking latch varies between generations. If the image appears skewed or the edges are not sharp after installation, the latch is usually not fully engaged; this is not typically a lens defect.
• Include the lens-shift margin in the installation plan. The shift range provides some installation flexibility, but edge image quality degrades when the lens is pushed to its limits. For actual use, keep operation within 70% of the rated shift values.

For models outside the list, the safest approach is to send us the chassis nameplate and a photo of the original lens for verification. Projectors on the same platform generation often share the same interface, but placing an order based only on a similar model designation creates unnecessary risk.