SC225 Projector Lens 0.85–1.37:1 for 3 Diheng Models (DU26K, DU22K, DU21K)

SC225 is a short-throw lens for 0.96-inch panels (Diheng), with a throw ratio of 0.85–1.37:1 and lens shift. It is compatible with 3 models across 1 model series. This article presents the lens specifications, installation distances, model compatibility list, and replacement considerations in one place.

1. Lens Specifications

Lens shift capability is the key distinction of this lens. A shift range of 10% horizontally and 4% vertically allows the projector to be installed off the screen centerline while the image is repositioned through lens shift, without requiring keystone correction. Keystone correction comes at a cost—each adjustment reduces the effective pixel count and softens text edges. In professional installations, lens shift should always be used instead of keystone correction whenever possible, as image quality depends on it.

2. Converting Throw Ratio to Installation Distance

The throw ratio is the ratio of installation distance to image width. This is a zoom lens (0.85–1.37:1), so each image size corresponds to a range of installation distances, and the lens can focus at any position within that range.

The distances above refer to the clear distance from the front of the lens to the screen and do not include space for rear chassis ventilation and cabling. Calculations are based on a 16:10 aspect ratio; actual values are subject to on-site measurements and the manual.

Image quality differs at the two ends of the zoom range: images are brighter with slightly softer edges toward the wide end, while edges are sharper and brightness is slightly lower toward the tele end. Where the venue allows, use the middle of the range. After installation, find the sharpest position on the focus ring before fine-tuning the shift—adjusting both at the same time makes precise alignment difficult.

3. Compatible Models (3 Models, Diheng)

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

The zoom ratio refers to the zoom factor of the model’s factory standard lens (upper throw ratio limit ÷ lower limit), not the zoom range of the lens described in this article.

Common Features of These Models

The factory standard lenses for all 3 models generally have throw ratios concentrated around 1.5~2.0. The 0.85–1.37:1 model in this article provides a different focal range, allowing the same projection distance to produce different image sizes—this is the direct reason for replacing the lens. It also retains full lens shift capability, so the image can still be aligned after changing the focal range.

4. Three Checks Before Replacement

• Confirm the panel and resolution match. This model is compatible with 0.96-inch panels. Projection performance may vary between projectors with different panel sizes or resolutions, so checking against the chassis nameplate before installation is the safest approach.
• Check the interface and locking mechanism. Interfaces are generally compatible within the same platform generation, but the position of the locking latch varies between generations. If the image is skewed or the edges are soft after installation, the lock is usually not fully engaged rather than the lens itself being faulty.
• Include lens-shift margin in the installation plan. The shift range provides some installation flexibility, but edge image quality declines when it is pushed to the limit. Actual use should be kept within 70% of the rated value.

For models not on the list, it is safer to send us the chassis nameplate and a photo of the original lens for verification—same-generation platforms often share interfaces, but placing an order based solely on a similar model carries unnecessary risk.