WB017 Projector Lens 0.78–0.81:1 for EIKI EK-308U and EK-309W

WB017 is a short-throw lens for 0.64-inch panels (EIKI), with a throw ratio of 0.78–0.81:1 and lens shift. It is compatible with 2 projector models in 1 model series. This article presents the lens specifications, installation distances, model compatibility list, and replacement considerations in one place.

1. Lens Specifications

Lens-shift capability is the key differentiator of this lens. The 76.00% horizontal and 47.70% vertical shift ranges allow the projector to be installed off the screen’s central axis, with the image repositioned through lens shift rather than keystone correction. Keystone correction comes at a cost—each adjustment sacrifices some effective pixels and softens text edges. In professional installations, use lens shift whenever possible instead of keystone correction; preserving image quality is the non-negotiable baseline.

2. Calculating Installation Distance from Throw Ratio

The throw ratio is the ratio of installation distance to image width. This is a zoom lens (0.78–0.81:1), so a given image size corresponds to a range of installation distances, and the lens can focus at any distance within that range.

The values above are clear distances from the front of the lens to the screen and do not include clearance behind the chassis for heat dissipation and cable connections. They are calculated for a 16:10 image; actual values are subject to on-site measurement and the manual.

Image quality differs at the two ends of the zoom range: toward the short end, the image is brighter but the edges are slightly softer; toward the long end, the edges are sharper but brightness decreases slightly. If site conditions allow, target the middle of the range. After installation, use the focus ring to find the sharpest setting, then fine-tune the lens shift—adjusting both variables at once makes precise alignment difficult.

3. Compatible Models (2 Models, EIKI)

The following table is ordered from newest to oldest by model production date and includes each model’s resolution, brightness, and factory-lens zoom ratio to help you quickly identify the right model for your project requirements.

The zoom ratio is the zoom factor of the model’s factory-standard lens (the upper ÷ lower limits of its factory throw ratio range), not the zoom range of the lens discussed in this article.

Common Traits of These Models

The factory-standard lenses for these 2 models generally have throw ratios of around 1.07-1.75:1. The 0.78–0.81:1 model featured here effectively changes the focal-length range, allowing different image sizes at the same projection distance—this is the direct reason for replacing the lens. It also retains the full lens-shift capability, so the image can still be aligned after the zoom range is changed.

4. Three Checks Before Replacement

• The panel and resolution must match. This model is designed for a 0.64-inch panel. Projectors with a different panel size or resolution will produce somewhat different projection performance, so checking the chassis nameplate before installation is the safest approach.
• Interfaces and locking mechanism. Same-generation platforms generally offer good interface compatibility, but the position of the locking latch varies by generation. If the image is skewed or the edges are soft after installation, the latch is usually not fully engaged; this is rarely an issue with the lens itself.
• Account for lens-shift margin in the installation. The shift range provides installation flexibility, but edge quality degrades when it is pushed to the limit. Keep actual use within 70% of the rated values.

For compatibility with a model not listed, it is safest to send us the chassis nameplate and a photo of the original lens for verification. Same-generation platforms often share interfaces, but the risk of ordering based on a similar model designation is not worth taking.