WK121 0.48:1 Projector Lens for 46 Panasonic Models, Including PT-VMQ65

The WK121 is a short-throw lens for 0.64-inch panels (Panasonic), with a 0.48:1 throw ratio and lens shift. It is compatible with 46 models in one model series. This article presents the lens specifications, installation distances, model compatibility list, and key replacement considerations in one place.

1. Lens Specifications

The key differentiator of this lens is its lens-shift capability. A shift range of 101% horizontal and 47.9% vertical allows the projector to be installed off the screen's center axis, with lens shift bringing the image back into alignment without keystone correction. Keystoning has a cost—each adjustment reduces the effective pixel count and blurs text edges. In professional installations, never use keystone correction when lens shift can solve the alignment issue; this is the non-negotiable standard for image quality.

2. Throw Ratio and Installation Distance

The throw ratio is the ratio of installation distance to image width. This lens has a fixed focal length (0.48:1), so the installation distance varies linearly with image size, leaving no room for adjustment. It must be measured accurately before installation.

These figures represent the clear distance from the front of the lens to the screen, excluding clearance for rear projector ventilation and cable connections. They are calculated for a 16:10 image; actual on-site measurements and the manual take precedence.

3. Compatible Models (46 Models, Panasonic)

The table below is sorted by model production date, from newest to oldest, and includes each model's resolution, brightness, and zoom ratio for the original lens, making it easy to identify the suitable option for a project's requirements.

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

Common Characteristics of These Models

The original standard lenses for the 46 models mostly fall within the 1.09-1.77:1 throw-ratio range. The 0.48:1 model featured here effectively changes the focal length, allowing a different image size at the same projection distance—the direct reason for replacing the lens. It also retains full lens-shift capability, so the image can still be aligned after the focal length is changed.

4. Three Checks Before Replacement

• Panel and resolution must match. This model is designed for 0.64-inch panels. Projectors with a different panel size or resolution will exhibit some differences in projection performance; the safest approach is to check the nameplate on the projector before installation.
• Interface and locking mechanism. Same-generation platforms generally offer good interface compatibility, but the position of the locking latch varies between generations. If the image appears skewed or the edges are not sharp after installation, the lock is usually not fully engaged rather than the lens itself being faulty.
• Lens-shift margin must be factored into the installation. The shift range provides flexibility during installation, but image quality at the edges declines when it is pushed to the limit. Actual use should remain within 70% of the nominal values.

For confirmation of compatibility with models not listed, the safest approach is to send us photos of the projector nameplate and the original lens for verification. Same-generation platforms often share interfaces, but ordering solely because model designations look similar carries unnecessary risk.