Appotronics X1.8 Zoom Telephoto Lens Overview: AL-FU10KA, AL-FU13KA, AL-FU650A, AL-FU720A, AL-FU850A

Appotronics Original Lens X1.8 Zoom is an OEM optical accessory for Appotronics engineering projectors. It is a long-throw lens (Long Throw) with a throw ratio of 1.20-2.30:1. The OEM compatibility list covers 5 models. Before installation, simply verify the projector model and panel size; there is no need to improvise with adapter rings. The value of an OEM lens lies not in the extra figures in the specification table, but in the fact that it is calibrated at the factory to the optical path and mount of that model series: the image circle, edge illumination, and focusing travel are all at their designed values, so there is no need to use keystone correction to compensate for image quality.

1. Lens Specifications

These specifications are subject to the OEM specifications. For mechanical dimensions, flange distance, and mount type not shown in the table, please check with us using 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 a zoom lens (1.20-2.30:1), so each image size corresponds to a range of installation distances, and the lens can focus at any distance within that range when installed.

These figures represent the clear distance from the lens front surface to the screen and do not account for rear housing ventilation and cabling space. They are calculated for a 16:10 image; actual distances should be verified on site and in accordance with the OEM manual.

Image quality differs at the two ends of the zoom range: nearer the near end, the image is brighter but the edges are slightly softer; nearer the far end, the edges are sharper but brightness is slightly lower. Where space permits, use the middle of the range. After installation, first find the sharpest position on the focus ring, then fine-tune the lens shift.

3. Compatible Models (5 Models)

The table below is taken from the OEM compatibility list. Brightness and resolution are populated from the model database; unavailable data is shown as “—” and has not been inferred.

To verify whether a model not on the list is compatible, send us photos of the projector nameplate and the existing lens—platforms of the same generation often share a mount, but ordering based on a similar model is not worth the risk.

Throw Ratios by Model Series

The rated throw ratio varies among the series listed below when the same X1.8 Zoom is installed. Select the value based on the series of the actual projector.

4. Three Checks Before Replacement

• Check the projector panel and resolution.Each OEM lens is designed for a specific panel size. If the panel specification differs, the image circle cannot cover the full image area, resulting in vignetting or edge light falloff.
• Calculate the installation distance first.This lens has a rated throw ratio of 1.20-2.30:1. Apply the table in Section 2 to your venue dimensions; fixed-focus lenses offer no adjustment margin, and zoom lenses still need 10–20 cm of allowance at both ends.
• Verify the mount and locking mechanism.The OEM lens is calibrated to the mount of that model series, and you must hear it lock into place after installation. A skewed image or soft edges are usually caused by an incompletely engaged lock, not by a defective lens.

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