Eiki AH-D21010 Zoom Long-Throw Lens: EIP-UJT100 Compatibility

Genuine Eiki Lens AH-D21010 Zoom is a factory-supplied optical accessory for Eiki engineering projectors. It is a long-throw (Long Throw) lens with a throw ratio of 1.87-2.56:1. The OEM compatibility list covers 1 model, so before installation, simply verify the projector model and panel size—no need to rely on adapter rings. The value of a genuine lens lies not in the extra figures in the specifications, but in the fact that it is calibrated at the factory to the optical path and lens mount of that model series: once installed, the image circle, edge illumination, and focus travel are all at their designed values, eliminating the need to use keystone correction to compensate for image quality.

1. Lens Specifications

The above specifications are subject to the manufacturer's original specifications. For mechanical dimensions, flange distance, and lens-mount configuration not shown in the specifications table, please check with us using the projector model. Ordering based solely on a similar model carries the risk that the lens will not fit.

2. Calculating Installation Distance from Throw Ratio

The throw ratio is the ratio of installation distance to image width. This genuine lens is a zoom model (1.87-2.56:1); a given image size corresponds to a range of installation distances, and the lens can focus anywhere within that range.

These figures represent the clear distance from the front surface of the lens to the screen and do not account for space behind the projector for cooling and cable connections. They are calculated for a 16:10 image; in practice, rely on on-site measurements and the manufacturer's manual.

Image quality varies at the two ends of the zoom range: toward the near end, the image is brighter and the edges slightly softer; toward the far end, the edges are sharper and the image slightly dimmer. Where the venue allows, use the middle of the range. After installation, first adjust the focus ring to the sharpest setting, then fine-tune the lens shift.

3. Compatible Projector Models (1 unit)

The table below is taken from the OEM compatibility list. Brightness and resolution are populated from the model database; where the data is unavailable, “—” is shown, with no assumptions made.

For compatibility with models not on the list, please send us photos of the projector nameplate and current lens for verification—platforms from the same generation often share a lens mount, but ordering based on a similar model is not worth the risk.

Throw Ratios by Model Series

When the same AH-D21010 Zoom lens is installed on the model series listed below, the nominal throw ratio varies. Use the value for the series of the actual projector when selecting a lens.

4. Three Checks Before Replacement

• Confirm the projector's chip and resolution. The original lens is 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 after installation.
• Calculate the installation distance first. This lens has a nominal throw ratio of 1.87-2.56:1. 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.
• Verify the lens mount and locking mechanism. The original lens is calibrated to the mount of that projector series, and you must hear it lock into place after installation. A skewed image or soft edges are usually caused by an incompletely locked lens, not by a problem with the lens itself.

If you are unsure, send us one photo each of the projector nameplate and the nameplate on the existing lens. Checking against the actual hardware is the safest approach.