Ricoh 512894 Zoom #8 Long Throw Lens Guide for PJ WU6181N PJ WX6181N

Ricoh Original Lens 512894 Zoom #8 is an OEM optical accessory for Ricoh professional projectors. It is a Long Throw lens with a throw ratio of 1.50-3.00:1. The official compatibility list covers 2 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 a genuine lens lies not in a few extra rows of specifications, 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 focus travel are all at their design values, so keystone correction is not needed to compensate for image quality.

I. Lens Specifications

Specifications are subject to the manufacturer's official specifications. For mechanical dimensions, flange distance, and mount type not listed in the specifications, please verify them with us using the exact projector model, as ordering based solely on a similar model carries the risk of a lens that does not fit.

II. Calculating Installation Distance from Throw Ratio

The throw ratio is the ratio of the installation distance to the image width. This genuine lens is a zoom lens (1.50-3.00:1), so a given image size corresponds to a range of distances, and it can focus at any position within that range.

These distances represent the clear distance from the front of the lens to the screen and do not include clearance for rear cooling and cabling. Calculations are based on a 16:10 image; actual values should be verified on site and according to the manufacturer's manual.

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

III. Compatible Models (2 Models)

The following table is based on the official compatibility list. Brightness and resolution are populated from the model database; unavailable entries are marked “—” and are not estimated.

For compatibility with models outside the list, please send us photos of the projector nameplate and the existing lens so we can verify them. Platforms of the same generation often share the same mount, but placing an order based on a similar model is not worth the risk.

Throw Ratios by Model Series

The rated throw ratio of the same 512894 Zoom #8 varies across the following model series. Select the value based on the actual projector series.

IV. Three Checks Before Replacement

• Confirm the projector 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 edge illumination loss.
• Calculate the installation distance first. The rated throw ratio of this lens is 1.50-3.00:1. Use the table in Section II to calculate the distance for your venue. Fixed-focus lenses offer no adjustment margin, and even zoom lenses should allow an extra 10–20 cm at both ends.
• Verify the mount and locking mechanism. The genuine lens is calibrated for the mount used on that projector series. After installation, you must hear the lens lock into place. A skewed image or soft edges are usually caused by incomplete locking rather than a problem with the lens itself.

If you are unsure, send us one photo of each nameplate—the projector and the existing lens. Verification against the physical units is the most reliable approach.