Appotronics XL240LA Telephoto Zoom Lens Guide: SK11KAS SK13KAS SK15KAS SU11KAS SU13KAS SU15KAS

Appotronics Genuine Lens XL240LA Telephoto Zoom is an OEM optical accessory for Appotronics engineering projectors. It is a long-throw (Long Throw) lens with a throw ratio of 2.40-3.80:1. The manufacturer’s compatibility list covers 6 models. Before installation, simply verify the projector model and panel size; there is no need to make do with an adapter ring. The value of a genuine lens lies not in the extra figures in the specifications, 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 there is no need to use keystone correction to compensate for image quality.

1. Lens Specifications

Brand	Appotronics（Appotronics）
Lens Model	XL240LA Telephoto Zoom
Throw Ratio	2.40-3.80:1
Product Type	Long-throw (Long Throw)
Compatible Models	6 models
Warranty	12 months; after-sales service is available for damage not caused by the user, based on the date shown on the shipping documents

These specifications are subject to the manufacturer’s official specifications. For mechanical dimensions, flange distance, and mount type not listed in the specifications table, please provide your projector model so we can verify compatibility. Placing an order based solely on a similar model carries the risk of an incompatible fit.

2. Calculating Installation Distance from Throw Ratio

The throw ratio is the ratio of the installation distance to the image width. This genuine zoom lens (2.40-3.80:1) covers a range of installation distances for any given image size and can focus throughout that range.

Image Size	Image Width	Required Installation Distance
100 inches	2.15 m	Approx. 5.16 – 8.17 m
120 inches	2.58 m	Approx. 6.19 – 9.80 m
150 inches	3.22 m	Approx. 7.74 – 12.25 m
200 inches	4.30 m	Approx. 10.32 – 16.34 m

The above figures represent the clear distance from the front surface of the lens to the screen and do not include space behind the projector for heat dissipation and cable connections. They are calculated for a 16:10 image; actual values should be verified on site and according to the manufacturer’s manual.

Image quality differs at the two ends of the zoom range: at the near end, the image is brighter and the edges are slightly soft; at the far end, the edges are sharper and the image is slightly dimmer. When the venue allows, it is recommended to use the middle of the range. After installation, find the sharpest setting on the focus ring first, then fine-tune the lens shift.

3. Compatible Projector Models (6 models)

The following table is taken from the manufacturer’s compatibility list. Brightness and resolution are populated from the model database; where the data is unavailable, they are marked “—” and are not estimated.

Model	Brightness	Resolution
SK11KAS	—	—
SK13KAS	—	—
SK15KAS	—	—
SU11KAS	—	—
SU13KAS	—	—
SU15KAS	—	—

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

Throw Ratio by Projector Model Series

The nominal throw ratio varies by series when the same XL240LA Telephoto Zoom lens is installed. Select the value based on the series of the actual projector.

Projector Model Series	Throw Ratio
—	2.40-3.80:1

4. Three Checks Before Replacement

• Confirm the projector chip and resolution. The genuine lens is designed for a specific panel size. If the panel specifications differ, the image circle cannot cover the full image, resulting in vignetting or edge light loss after installation.
• Calculate the installation distance first. This lens has a rated throw ratio of 2.40-3.80:1. Use the table in Section 2 to calculate the distance for your venue. A fixed-focus lens offers no adjustment margin, and even a zoom lens requires a 10–20 cm margin at both ends.
• Verify the mount and locking mechanism. The genuine lens is calibrated to the mount of projectors in this series, and you must hear the lock engage fully after installation. Image misalignment and soft edges are usually caused by incomplete locking rather than a problem with the lens itself.

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