Vivitek 3797859900-SVK Short Zoom 2 Standard Throw Lens Review for DU9800Z-BK

Vivitek Original Lens 3797859900-SVK Short Zoom 2 is an original optical accessory for Vivitek engineering projectors. It is a standard-throw lens (Standard Throw) with a throw ratio of 1.20-1.56:1, designed for DU/DW/DX engineering-series inch panels. The factory compatibility list covers 1 model. Before installation, simply verify the projector model and panel size; there is no need to rely on an adapter ring. The value of an original lens lies not in the extra figures in a specification sheet, but in the fact that it is calibrated at the factory to the optical path and mount of the corresponding projector series: once installed, the image circle, edge illumination, and focus travel are all at their designed values, with no need to use keystone correction to compensate for image quality.

I. Lens Specifications

Brand	Vivitek (Vivitek)
Lens Model	3797859900-SVK Short Zoom 2
Throw Ratio	1.20-1.56:1
Product Type	Standard throw (Standard Throw)
Applicable Panels	DU/DW/DX engineering-series inch panels
Models Covered	1 unit
Warranty	12 months; damage not caused by the user is eligible for after-sales service, subject to the date shown on the shipping invoice

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

II. Calculating Installation Distance from the Throw Ratio

The throw ratio is the ratio of installation distance to image width. This original lens is a zoom lens (1.20-1.56:1). A given image size corresponds to a range of installation distances, and the lens can focus at any point within that range.

Image Size	Image Width	Required Installation Distance
100 inches	2.15 m	approx. 2.58 – 3.35 m
120 inches	2.58 m	approx. 3.10 – 4.02 m
150 inches	3.22 m	approx. 3.87 – 5.03 m
200 inches	4.30 m	approx. 5.16 – 6.71 m

These figures represent the clear distance from the front of the lens to the screen and do not include space for cooling and cable connections at the rear of the projector. They are calculated for a 16:10 image; actual distances should be verified on site and confirmed against the factory manual.

Image quality varies between the two ends of the zoom range: near the short-throw end, the image is brighter and the edges are slightly softer; near the long-throw end, the edges are sharper but brightness is slightly lower. When the venue allows, use the middle of the range. After installation, find the sharpest position using the focus ring, then fine-tune the lens shift.

III. Compatible Models (1 Unit)

The following table is taken from the factory compatibility list. Brightness and resolution are populated from the model database; values that cannot be retrieved are marked "—" and are not estimated.

Model	Brightness	Resolution
DU9800Z-BK	18000 lumens	1920x1200

For models outside this list, please send us photos of the projector nameplate and the existing lens so we can verify compatibility. Projector platforms from the same generation often share a mount, but ordering based solely on a similar model number carries risks that are not worth taking.

Throw Ratio by Projector Series

The rated throw ratio differs when the same 3797859900-SVK Short Zoom 2 lens is used with the series listed below. For model selection, use the value for the series to which the actual projector belongs.

Projector Series	Throw Ratio
—	1.20-1.56:1

IV. Three Checks Before Replacement

• Confirm the panel size. The 3797859900-SVK Short Zoom 2 is designed for DU/DW/DX engineering-series inch panels. Projectors with a different panel size or resolution may have image-circle and edge-illumination issues even if the lens fits the mount.
• Calculate the installation distance first. This lens has a rated throw ratio of 1.20-1.56:1. Use the table in Section II to calculate the distance for your venue. A fixed-focus lens has no adjustment margin, while a zoom lens should also allow 10–20 cm of margin at both ends.
• Verify the mount and locking mechanism. The original lens is calibrated to the mount of the corresponding projector series and must be heard to click into its locked position after installation. A skewed image or soft edges are usually caused by incomplete locking, not by a problem with the lens itself.

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