Eiki AH-AC22070 Zoom Standard Throw Projector Lens: Compatible with EK-831DU EK-831U EK-833DU

Eiki Original Lens AH-AC22070 Zoom is a genuine optical accessory for Eiki installation projectors, belonging to the standard throw category, with a throw ratio of 1.14-1.71:1. The original compatibility list covers 4 projector models; before installation, simply verify against the projector model and panel size—no need to rely on adapter rings. The value of an original lens isn't in a few extra rows of numbers on a spec sheet, but in the fact that it is calibrated at the factory to the optical path and mount of that series' chassis: once installed, the image circle, edge illumination, and focus travel are all at their design values, with no need to compensate for image quality using keystone correction.

1. Lens Specifications

Brand	Eiki (Eiki)
Lens Model	AH-AC22070 Zoom
Throw Ratio	1.14-1.71:1
Product Type	Standard Throw
Compatible Models	4
Warranty	12 months; after-sales service available for non-human damage, based on the date on the shipping document

The above specifications are subject to the original manufacturer's specifications. For mechanical dimensions, flange focal distance, and mount type not shown in the spec table, please verify with us against the projector model—ordering based on model similarity alone 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 (1.14-1.71:1), so the same image size corresponds to a range of distances; as long as installation falls within this range, focus can be achieved.

Image Size	Image Width	Required Installation Distance
100 inches	2.15 m	Approx. 2.45 – 3.68 m
120 inches	2.58 m	Approx. 2.94 – 4.41 m
150 inches	3.22 m	Approx. 3.68 – 5.51 m
200 inches	4.30 m	Approx. 4.90 – 7.35 m

The above are clear distances from the lens face to the screen, excluding rear ventilation and cabling space behind the projector. 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 (4)

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.

Model	Brightness	Resolution
EIKI EK-831DU	—	—
EIKI EK-831U	—	—
EIKI EK-833DU	—	—
EIKI EK-836DU	—	—

To determine whether models outside the list are compatible, please send us photos of the projector nameplate and the existing lens for verification—same-generation platforms often share mounts, but ordering based on model similarity is not worth the risk.

Throw Ratios Across Model Series

The same AH-AC22070 Zoom installed on the following series does not have the same nominal throw ratio; selection must use the value for the actual chassis series.

Model Series	Throw Ratio
—	1.14-1.71:1

4. Three Things to Confirm Before Replacement

• Confirm the projector chip and resolution. The original lens is designed for a specific panel size; 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 1.14-1.71:1; apply it to your venue dimensions using the table in Section 2. Prime lenses have no margin, and even zoom lenses need 10–20 cm of allowance at both ends.
• Verify the mount and locking. The original lens is calibrated to that series' chassis mount; after installation, you must hear it lock into place. Image skew 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.