EIKI AH-EC21020 Zoom Long-Throw Lens for 5 Models: EK-1000LU EK-1100LU EK-1300LU EK-850LU EK-900LU

Eiki Original Lens AH-EC21020 Zoom is an original optical accessory for Eiki professional projectors. It is a long-throw lens (Long Throw) with a throw ratio of 1.30-3.02:1. The official compatibility list covers 5 models. Before installation, simply verify the projector model and panel size; there is no need to improvise with adapter rings. The value of an original lens lies not in the additional figures on a 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 the design values, eliminating the need for keystone correction to compensate for image quality.

I. Lens Specifications

The above specifications are subject to the official specifications. For mechanical dimensions, flange distance, and mount type not listed in the specification table, please provide the exact projector model so we can verify them for you. Ordering solely based on a similar model carries the risk of the lens not fitting.

II. Calculating Installation Distance from the Throw Ratio

The throw ratio is the ratio of the installation distance to the image width. This original lens is a zoom lens (1.30-3.02:1), so each image size corresponds to a range of installation distances. The lens can focus at any position within that range.

These figures represent the clear distance from the front of the lens to the screen and do not include space for rear housing ventilation or cabling. The distances are calculated for a 16:10 image; actual measurements on site and the manufacturer's manual take precedence.

Image performance differs at the two zoom extremes: the image is brighter and the edges slightly softer toward the short-throw end, while the edges are sharper and brightness is slightly lower toward the long-throw end. Where the venue allows, placing the lens near the middle of the range is recommended. After installation, first find the sharpest position using the focus ring, then fine-tune the lens shift.

III. Compatible Projector Models (5 Models)

The table below is taken from the official compatibility list. Brightness and resolution are populated from the model database; unavailable specifications are marked with "—", and no assumptions are made.

To check whether a model outside the list is compatible, send us photographs of the projector nameplate and the existing lens. Projector platforms of the same generation often share mounts, but the risk of ordering solely based on a similar model is not worth taking.

Throw Ratios by Model Series

When the same AH-EC21020 Zoom is installed on the following series, the rated throw ratios differ. Select the value for the series of the actual projector.

IV. Three Checks Before Replacement

• Confirm the projector panel 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 light loss at the edges.
• Calculate the installation distance first.This lens has a rated throw ratio of 1.30-3.02:1. Use the table in Section II to calculate the distance for your venue; fixed-focus lenses offer no adjustment margin, while zoom lenses should also allow an additional 10–20 cm at both ends.
• Verify the mount and locking mechanism.The original lens is calibrated to the mount of that projector series. You must hear it click fully into lock after installation. A skewed image or soft edges are usually caused by incomplete locking rather than a problem with the lens itself.

If you are unsure, take one photograph of the projector nameplate and one of the existing lens nameplate, then send them to us. Verification against the actual equipment is the most reliable option.