Optoma BX-DL500 Zoom Telephoto Lens Guide: EH503 EH503e EH505 EH505-B EH505e W505 X605 X605e

Optoma original lens BX-DL500 Zoom is an OEM optical accessory for Optoma engineering projectors. It is a Long Throw lens with a throw ratio of 3.15-5.30:1. The factory compatibility list covers 8 models. Before installation, verify the projector model and panel size; there is no need to improvise with adapter rings. Its value lies not in a few extra lines in the specifications, but in factory calibration to the optical path and mount of that projector series: the image circle, edge illumination, and focus travel all match their design values, so keystone correction is not needed to compensate for image quality.

1. Lens Specifications

These specifications are subject to the OEM specifications. Mechanical dimensions, flange distance, and mount type are not shown in the table. Please contact us with the projector model for verification; ordering based solely on a similar model carries the risk that the lens will not fit.

2. Converting Throw Ratio into Installation Distance

The throw ratio is the ratio of the installation distance to the image width. This OEM lens is a zoom lens (3.15-5.30:1), so a given image size corresponds to a range of installation distances, with focus achievable anywhere within that range.

These figures represent the clear distance from the front of the lens to the screen and do not include clearance for rear projector ventilation or cable connections. They are calculated for a 16:10 image; actual installation should be verified on site and according to the manufacturer's manual.

Image quality differs at the two ends of the zoom range: images are brighter with slightly softer edges near the short end, while edges are sharper but slightly dimmer near the long end. Where the venue allows it, the middle of the range is recommended. After installation, find the sharpest position on the focus ring, then fine-tune the lens shift.

3. Compatible Models (8 Projectors)

The table below is based on the factory compatibility list. Brightness and resolution values are populated from the model database; unavailable entries are marked “—” rather than estimated.

For models not on the list, send us photos of the projector nameplate and the existing lens for verification. Platforms of the same generation often share mounts, but ordering based solely on similar model names is not worth the risk.

Throw Ratio by Model Series

When the same BX-DL500 Zoom lens is used with the series listed below, the rated throw ratio varies. Select the value based on the actual projector series.

4. Three Checks Before Replacement

• Confirm the projector chip and resolution. OEM lenses are 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.
• Calculate the installation distance first. This lens has a rated throw ratio of 3.15-5.30:1. Use the table in Section 2 to determine the distance for your venue. A fixed-focus lens has no distance margin, while a zoom lens still requires 10–20 cm of clearance at both ends.
• Check the mount and locking mechanism. OEM lenses are calibrated to the mount of the corresponding projector series. After installation, you must hear the lens lock fully into place. Image misalignment and soft edges are usually caused by incomplete locking, not by the lens itself.

If you are unsure, take one photo of each nameplate—the projector and the existing lens—and send them to us for verification against the actual hardware.