Barco EN54 Long Zoom Lens Guide: CTHD-61B CTPN-41B CTWQ-51B CTWU-61B Orion Cinemascope

The genuine Barco EN54 Long Zoom lens is an original optical accessory for Barco engineering projectors. It is a long-throw lens with a 2.68-4.18:1 throw ratio. The OEM compatibility list covers 5 projector models. Before installation, simply verify the projector model and panel size; no adapter ring is needed. The value of a genuine lens lies not in the additional figures on a specification sheet, but in the fact that it is calibrated at the factory to the optical path and lens mount of that projector series. Once installed, image circle coverage, edge illumination, and focus travel are all within their design values, so keystone correction is unnecessary to compensate for image quality.

1. Lens Specifications

Brand	Barco (Barco)
Lens Model	EN54 Long Zoom
Throw Ratio	2.68-4.18:1
Product Type	Long Throw (Long Throw)
Compatible Models	5 models
Warranty	12 months; for damage not caused by the user, after-sales service applies, based on the date on the sales invoice

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

2. Calculating Installation Distance from Throw Ratio

The throw ratio is the ratio of the installation distance to the image width. This genuine lens is a zoom lens (2.68-4.18:1), so a given image size corresponds to a range of installation distances. It can focus at any position within that range.

Image Size	Image Width	Required Installation Distance
100 inches	2.15 m	approx. 5.76 – 8.99 m
120 inches	2.58 m	approx. 6.91 – 10.78 m
150 inches	3.22 m	approx. 8.64 – 13.48 m
200 inches	4.30 m	approx. 11.52 – 17.97 m

The distances above are clear distances from the front face of the lens to the screen and do not include ventilation or cable-management space at the rear of the projector. They are calculated for a 16:10 image; actual distances should be verified through on-site measurements and in accordance with the manufacturer's manual.

Image quality varies at the two ends of the zoom range: the image is brighter and the edges are slightly softer near the short-throw end, while the edges are sharper and the brightness is slightly lower near the long-throw end. Where the venue allows, use the middle of the range. After installation, first find the sharpest position using the focus ring, and then fine-tune the shift.

3. Compatible Models (5 Models)

The table below is taken from the OEM compatibility list. Brightness and resolution are populated from the model database; unavailable values are shown as “—” and are not estimated.

Model	Brightness	Resolution
CTHD-61B	5500 lumens	1920x1080
CTPN-41B	3800 lumens	2560x1080
CTWQ-51B	5000 lumens	2560x1600
CTWU-61B	5500 lumens	1920x1200
Orion Cinemascope	—	—

To determine whether a model outside the list is compatible, send us photos of the projector nameplate and the existing lens. Platforms of the same generation often share the same mount, but ordering based solely on a similar model carries an unnecessary risk.

Throw Ratio by Projector Series

Although the same EN54 Long Zoom lens is used with the series listed below, the nominal throw ratio varies. Select the value according to the actual projector series.

Projector Series	Throw Ratio
—	2.68-4.18:1

4. Three Checks Before Replacement

• Confirm the projector chip and resolution. Genuine lenses are designed for a specific panel size. If the panel specifications differ, the image circle cannot cover the full image, resulting in vignetting or light loss at the edges.
• Calculate the installation distance first. This lens has a rated throw ratio of 2.68-4.18:1. Use the table in Section 2 to calculate the distance for your venue. Fixed-focus lenses offer no adjustment margin, and zoom lenses should also have 10–20 cm of clearance at both ends of the range.
• Verify the mount and locking mechanism. Genuine lenses are calibrated to the mounts used on that projector series. After installation, you must hear the lens click into the locked position. A skewed image or soft edges are usually caused by incomplete locking rather than a problem with the lens itself.

If you are unsure, send us one photo each of the projector nameplate and the current lens nameplate so that we can verify them against the physical products.