BenQ LS1SD Standard Zoom Lens Analysis: LU9915 Compatibility

BenQ Original Lens LS1SD Standard Zoom is an original optical accessory for BenQ business projectors. It belongs to the standard-throw category (Standard Throw) and has a throw ratio of 1.73:1 - 2.27:1. The manufacturer's compatibility list covers 1 model; simply verify the projector model and panel size before installation—no need to make do with adapter rings. The value of an OEM lens lies not in the extra figures on a spec sheet, 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 range are all at their design values, so there is no need to use keystone correction to compensate for image quality.

I. Lens Specifications

The above specifications are subject to the manufacturer's specifications. For the mechanical dimensions, flange distance, and mount type not shown in the specifications table, please contact us with the exact projector model for verification. Placing an order solely because the model numbers are similar carries the risk that the lens will not fit.

II. Converting Throw Ratio to Installation Distance

The throw ratio is the ratio of the installation distance to the image width. This OEM lens is a zoom lens (1.73:1 - 2.27:1), so the same image size corresponds to a range of distances, and it can be focused at any position within that range during installation.

These are net distances from the front surface of the lens to the screen and do not include clearance for the projector's rear ventilation and wiring. The calculations are based on a 16:10 image; actual distances should be verified through on-site measurement and in accordance with the manufacturer's manual.

Image quality differs at the two ends of the zoom range: closer to the near end, the image is brighter and the edges are slightly softer; closer to the far end, the edges are sharper and the image is slightly dimmer. Where site conditions allow, use the middle of the range. After installation, first find the sharpest position on the focus ring, then fine-tune the lens shift.

III. Compatible Projector Models (1 Unit)

The following table is taken from the manufacturer's compatibility list. Brightness and resolution have been populated from the model database; where the data is unavailable, an em dash (—) is shown rather than making assumptions.

For models not included in the list, please send us photos of the projector nameplate and the existing lens for verification—platforms of the same generation often share the same mount, but ordering based on a superficially similar model is not worth the risk.

Throw Ratios by Model Series

The rated throw ratio differs between the series listed below when the same LS1SD Standard Zoom lens is installed. Select the value based on the series of the actual projector.

IV. Three Checks Before Replacement

• Confirm the projector's imaging chip and resolution. OEM lenses are designed for a specific panel size. If the panel specifications differ, the image circle cannot cover the panel, resulting in vignetting or light loss at the edges.
• Calculate the installation distance first. This lens has a rated throw ratio of 1.73:1 - 2.27:1. Use the table in Section II to calculate the distance for your venue's screen size; fixed-focus lenses offer no adjustment margin, and zoom lenses should also allow 10–20 cm at both ends of the range.
• Verify the mount and locking mechanism. OEM lenses are calibrated to the mount of the corresponding projector series. After installation, you must hear the lens click into the locked position; a skewed image and soft edges are usually caused by incomplete locking rather than a lens defect.

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 safest approach.