EIKI AH-B23010 Zoom Long-Throw Projector Lens: EK-800U Compatibility

Eiki Original Lens AH-B23010 Zoom is an original optical accessory for Eiki engineering projectors. It is a long-throw (Long Throw) lens with a throw ratio of 4.00-7.20:1. The factory compatibility list covers 1 model, so before installation, simply verify the projector model and panel size—there is no need to resort to adapter rings. The value of an original lens lies not in the extra rows of figures in the specification sheet, 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 as designed, so there is no need to use keystone correction to compensate for image-quality limitations.

I. Lens Specifications

Specifications are subject to the original manufacturer's specifications. For mechanical dimensions, flange distance, and mount type not listed in the specification table, please provide your projector model to us for verification. Placing an order based solely on a similar model carries the risk of an incompatible fit.

II. Converting Throw Ratio into Installation Distance

The throw ratio is the ratio of installation distance to image width. This original lens is a zoom lens (4.00-7.20:1), so the same image size corresponds to a range of installation distances, and it can focus at any distance within that range.

These figures represent the clear distance from the front surface of the lens to the screen and do not include clearance behind the projector for ventilation and cabling. They are calculated for a 16:10 image; actual values must be verified on site and according to the original manufacturer's manual.

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

III. Compatible Models (1 Model)

The following table is taken from the factory compatibility list. Brightness and resolution are populated from the model database; unavailable values are shown as “—” and have not been estimated.

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

Throw Ratios by Model Series

The nominal throw ratio differs when the same AH-B23010 Zoom is installed on the following series, so the selection should be based on the series of the actual projector.

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 light loss after installation.
• Calculate the installation distance first. This lens has a nominal throw ratio of 4.00-7.20:1. Use the table in Section 2 to match the dimensions of your venue. A prime lens offers no adjustment range, and a zoom lens also requires 10–20 cm of margin at both ends.
• Verify the mount and locking mechanism. The original lens is calibrated to the mount of that projector series. After installation, it must audibly click into the locked position. Image skew and soft edges are usually caused by incomplete locking rather than 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. Verification against the actual items is the safest approach.