BenQ 5J.JAM37.031 Long Zoom 1 Long-Throw Lens: Compatible with 9 Models

BenQ Original Lens 5J.JAM37.031 Long Zoom 1 is an original optical accessory for BenQ professional projectors. It is a long-throw lens with a throw ratio of 3.58:1 - 5.38:1. The manufacturer's compatibility list covers 9 projector models, so you only need to verify the projector model and panel size before installation—no need to improvise with an adapter ring. The value of an original lens lies not in the extra rows of figures in the specification sheet, but in its factory calibration to the optical path and mount of that projector series: the image circle, edge illumination, and focus travel all meet the design specifications, so there is no need to use keystone correction to compensate for image quality.

1. Lens Specifications

The above parameters are subject to the manufacturer's original specifications. Mechanical dimensions, flange distance, and mount type are not shown in the specification table; please verify them with us using the projector model. Ordering based solely on a similar model number carries the risk of a fitment failure.

2. Converting Throw Ratio to Installation Distance

The throw ratio is the ratio of the installation distance to the image width. This original zoom lens (3.58:1 - 5.38:1) covers a range of installation distances for a given image size and can focus at any distance within that range.

The distances above are clear distances from the front surface of the lens to the screen and do not include space for cooling at the rear of the projector or for cable connections. The values are calculated for a 16:10 image; actual installation should be confirmed by on-site measurement and the manufacturer's manual.

Image quality varies at the two ends of the zoom range: toward the short end, the image is brighter and the edges are slightly softer; toward the long end, the edges are sharper and brightness is slightly lower. When the venue permits, we recommend positioning the lens in 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 (9 Models)

The table below is taken from the manufacturer's compatibility list. Brightness and resolution are filled in from the model database; values that cannot be found are marked “—” rather than estimated.

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

Throw Ratio by Projector Series

The nominal throw ratio differs when the same 5J.JAM37.031 Long Zoom 1 lens is used with the series listed below. When selecting a lens, use the value for the series of the actual projector.

4. Three Checks Before Replacement

• Confirm the projector imaging chip and resolution. Original 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 light loss at the edges.
• Calculate the installation distance first. This lens has a nominal throw ratio of 3.58:1 - 5.38:1; use the table in Section 2 to calculate the distance for your venue. A fixed-focus lens provides no adjustment margin, and even a zoom lens should have a 10–20 cm margin at both ends.
• Verify the mount and locking mechanism. The original lens is calibrated to the mount of that projector series. After installation, you must hear the lens click into the locked position. Image skew or soft edges usually indicate that the lens has not fully locked, rather than a problem with the lens itself.

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