Eiki AH-B21010 Zoom Standard Throw Projector Lens: EK-800U Compatible

Eiki Original Lens AH-B21010 Zoom is a genuine optical accessory for Eiki installation projectors. It is a standard throw lens with a throw ratio of 1.50-2.00:1. The original compatibility list covers 1 projector model; before installation, simply verify against the projector model and panel size — no adapter rings are needed. The value of an original lens is not about extra rows of numbers in the spec sheet, but that it is calibrated at the factory to the optical path and bayonet of that projector series: once mounted, the image circle, edge illumination, and focus travel are all at their design values, so you don't need keystone correction to compensate for image quality.

1. Lens Specifications

The above specifications are subject to the original manufacturer's specifications. For mechanical dimensions, flange focal distance, and bayonet type not shown in the spec table, please verify with us against the projector model — ordering based on a similar model number carries the risk of incompatibility.

2. Converting Throw Ratio to Installation Distance

Throw ratio is the ratio of installation distance to image width. This original lens is a zoom lens (1.50-2.00:1), so the same image size corresponds to a range of distances; as long as installation falls within this range, focus can be achieved.

The above figures are the clear distance from the lens front to the screen, excluding rear ventilation and cabling space behind the projector body. Calculated for 16:10 aspect ratio; actual values are subject to on-site measurement and the original manufacturer's manual.

Image quality differs at the two ends of the zoom range: toward the near end the image is brighter with slightly softer edges; toward the far end the edges are sharper with slightly reduced brightness. Where space permits, it is recommended to land in the middle of the range. After installation, first find the sharpest position on the focus ring, then fine-tune the shift.

3. Compatible Models (1 projector)

The table below is taken from the original compatibility list; brightness and resolution are filled in from the model database, with "—" where unavailable — no speculation.

For whether models outside the list can be used, please send us photos of the projector nameplate and the existing lens for verification — same-generation platforms often share bayonets, but ordering based on a similar model number is not worth the risk.

Throw Ratios Across Model Series

The same AH-B21010 Zoom mounted on the following series has different nominal throw ratios; selection should be based on the series of the actual projector.

4. Three Things to Confirm Before Replacement

• Confirm the projector's chip and resolution. Original lenses are designed for specific panel sizes; with a different panel specification, the image circle cannot cover it, resulting in vignetting or edge light loss after installation.
• Calculate the installation distance first. This lens has a nominal throw ratio of 1.50-2.00:1; use the table in Section 2 to map it to your venue's dimensions. Fixed-focus lenses have no margin, and even for zoom lenses, allow 10–20 cm at both ends.
• Verify the bayonet and locking. Original lenses are calibrated to the bayonet of that projector series; after installation, you must hear the lock engage. Skewed images and soft edges are mostly due to incomplete locking, not a problem with the lens itself.

If unsure, take a photo of the projector nameplate and the existing lens nameplate and send them to us — verification against the actual hardware is the most reliable approach.