NEC NP20ZL-4K Zoom Long-Throw Lens for PX1005QL-B, PX1005QL-B-18, PX1005QL-W, PX1005QL-W-18

NEC Original Lens NP20ZL-4K Zoom is an original optical accessory for NEC projectors, featuring a long-throw (Long Throw) design and a throw ratio of 3.54-5.36:1. The factory compatibility list covers 4 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 extra rows of specifications, but in the fact that it is factory-calibrated to the optical path and mount of the projector series: once installed, image-circle coverage, edge illumination, and focus travel all meet their design values, so there is no need to use keystone correction to compensate for image quality.

1. Lens Specifications

The above specifications are subject to the manufacturer's specifications. For mechanical dimensions, flange distance, and mount type not shown in the specifications table, please contact us for verification based on the projector model. Ordering solely on the basis of a similar model carries the risk that the lens will not fit.

2. Calculating Installation Distance from Throw Ratio

Throw ratio is the ratio of installation distance to image width. This original lens has a zoom function (3.54-5.36:1), so a given image size corresponds to a range of installation distances, and the lens can focus at any position within that range.

These are net distances from the front lens element to the screen and do not include space behind the projector for ventilation and cable connections. They are calculated for a 16:10 image; actual distances should be verified through on-site measurement and the manufacturer's manual.

Image quality varies at the two ends of the zoom range: toward the shorter-distance end, the image is brighter and the edges are slightly softer; toward the longer-distance end, the edges are sharper and brightness is slightly lower. When site conditions allow, aim for the middle of the range. After installation, turn the focus ring to find the sharpest position, then fine-tune the lens shift.

3. Compatible Projector Models (4 Models)

The following table is taken from the factory compatibility list. Brightness and resolution are populated from the projector model database; unavailable data is shown as “—” rather than estimated.

To verify whether a model outside the list is compatible, please send us photos of the projector nameplate and the existing lens. Platforms of the same generation often share the same mount, but ordering based on a similar model is not worth the risk.

Throw Ratio by Projector Model Series

The nominal throw ratio differs when the same NP20ZL-4K Zoom lens is used with the series listed below. Use the value corresponding to the series of the actual projector when selecting a lens.

4. Three Checks Before Replacement

• Confirm the projector chip and resolution. The original lens is designed for a specific panel size. If the panel specifications differ, the image circle cannot cover the panel, causing vignetting or edge light loss after installation.
• Calculate the installation distance first. This lens has a nominal throw ratio of 3.54-5.36:1. Use the table in Section 2 to calculate the distance for your venue. Prime lenses offer no adjustment margin, while a zoom lens should still allow an extra 10–20 cm at both ends of the range.
• Verify the mount and locking mechanism. The original lens is calibrated for the mount of that projector series. After installation, you must hear the lens click into the locked position. A skewed image or soft edges most often indicate that the lock is not fully engaged, rather than a problem with the lens itself.

If you are unsure, send us one photo each of the projector nameplate and the existing lens nameplate. Verification against the physical units is the most reliable approach.