Panasonic ET-ELT31 Long-Throw Lens: Compatible with 14 Projector Models

Panasonic Genuine Lens ET-ELT31 is an official optical accessory for Panasonic business projectors. It is a long-throw lens (Long Throw) with a throw ratio of 4.02-7.20:1 for 0.76" 3LCD panels. The official model compatibility list covers 14 projector models; before installation, simply verify the projector model and panel size—there is no need to make do with adapter rings. The value of a genuine lens lies not in the additional figures in the specification sheet, but in its factory calibration to the optical path and mount of that projector series. Once installed, the image circle, edge illumination, and focus travel all meet 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 published specifications. For mechanical dimensions, flange distance, and mount type not shown in the table, please check with us using the projector model. Ordering solely on the basis of a similar model carries the risk that the lens will not fit.

II. Calculating Installation Distance from Throw Ratio

The throw ratio is the ratio of installation distance to image width. This genuine lens has a zoom range (4.02-7.20:1), so a given image size corresponds to a range of distances, and the lens can focus anywhere within that range.

These figures represent the clear distance from the front of the lens to the screen and do not include space behind the projector for ventilation or cable connections. They are calculated for a 16:10 image; actual distances should be confirmed by on-site measurement and the manufacturer's manual.

Image quality differs between the two ends of the zoom range: at the shorter-throw end, the image is brighter and the edges slightly softer; at the longer-throw end, the edges are sharper and the image slightly dimmer. Where the venue allows, use the middle of the range. After installation, first find the sharpest image using the focus ring, then fine-tune the lens shift.

III. Compatible Projector Models (14 Models)

The table below is taken from the official model compatibility list. Brightness and resolution are populated from the model database; unavailable data is shown as “—” rather than estimated.

To check compatibility with projector models not on the list, please send us photos of the projector nameplate and the current lens. Projector platforms from the same generation often share the same mount, but it is not worth the risk of ordering solely because the model numbers are similar.

Throw Ratios by Projector Series

The rated throw ratio varies by projector series when the same ET-ELT31 is installed. When selecting a lens, use the value for the series of the actual projector.

IV. Three Checks Before Replacement

• Make sure the panel size matches. ET-ELT31 is designed for 0.76" 3LCD panels. Even if the lens fits the mount, projectors with a different panel size or resolution may experience image circle and edge illumination problems.
• Calculate the installation distance first. This lens has a rated throw ratio of 4.02-7.20:1; use the table in Section 2 to calculate the distance for your venue. A fixed-focus lens offers no adjustment margin, so allow an additional 10–20 cm at both ends of the range even with a zoom lens.
• Verify the mount and locking mechanism. The genuine lens is calibrated to the mount used on that projector series. After installation, you must hear it lock into place. A skewed image or soft edges are usually caused by incomplete locking, not by the lens itself.

If you are unsure, photograph both the projector nameplate and the nameplate on the current lens and send the images to us. Checking against the actual hardware is the safest approach.