Optoma BX-CTA01 Standard Zoom Lens Guide: ZU1050 ZU850 ZU660

Optoma OEM Lens BX-CTA01 Standard Zoom is a factory-supplied optical accessory for Optoma professional projectors. It is a standard-throw lens (Standard Throw) with a throw ratio of 0.95-1.22:1 (standard zoom), designed for a 0.67" DLP (ProScene ZU series) panel. The OEM compatibility list covers 3 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 an OEM lens lies not in the extra rows of figures in its specifications, but in the fact that it is calibrated at the factory to the optical path and mount of the relevant model series. Once installed, the image circle, edge illumination, and focus travel are all at their design values, so there is no need to use keystone correction to compensate for image quality.

1. Lens Specifications

The above specifications are subject to the original manufacturer's specifications. For mechanical dimensions, flange distance, and mount type not listed in the specifications table, please contact us with the projector model to verify these details; placing an order based solely on a similar model carries the risk that the lens may not fit.

2. Converting Throw Ratio to Installation Distance

The throw ratio is the ratio of installation distance to image width. This OEM lens is a zoom lens (0.95-1.22:1 (standard zoom)); a given image size corresponds to a range of installation distances, and the lens can focus at any point within that range.

These figures represent the clear distance from the front surface of the lens to the screen and do not allow for rear housing ventilation or cable-routing space. They are calculated for a 16:10 image aspect ratio; actual values should be confirmed through on-site measurements and the original manufacturer's manual.

Image quality differs at the two ends of the zoom range: toward the short-throw end, the image is brighter and the edges are slightly softer; toward the long-throw end, the edges are sharper and brightness decreases slightly. Where venue conditions allow, position the lens near the middle of the range. After installation, first find the sharpest setting on the focus ring, then fine-tune the lens shift.

3. Compatible Models (3 Models)

The following table is taken from the OEM compatibility list. Brightness and resolution are populated from the model database; values that cannot be obtained are shown as "—" without speculation.

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

Throw Ratios by Model Series

The rated throw ratio varies by model series when the same BX-CTA01 Standard Zoom lens is used. Select the value based on the series of the actual projector.

4. Three Checks Before Replacement

• The panel size must match.BX-CTA01 Standard Zoom is designed for a 0.67" DLP (ProScene ZU series) panel. Projectors with a different panel size or resolution may exhibit 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 0.95-1.22:1 (standard zoom). 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 10–20 cm of clearance at both ends.
• Check the mount and locking mechanism.The OEM lens is calibrated to the mount of this model series, and you must hear it lock into place after installation. A skewed image 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 current lens nameplate and send them to us. Verification against the actual items is the safest approach.