Proxima Desktop Projector 6850+ with ProjectionLink
$8,495 (Proxima 6850+)
Pros: Exceeds manufacturer's specs. Good all-around performance. Uniformly illuminated images. Equipped with a motorized-zoom lens.
Cons: Could use better color mapping in video mode. ProjectionLink feature is an expensive addition.
Weight: 13.2 pounds. Data and power cord plus remote control weigh an additional 1.6 pounds.
LCD size and resolution: 1.3-inch XGA (1,024 x 768).
Optics: Three-panel microlens LCDs with dichroic x-cube and integrated polarization conversion. Motorized-zoom and -focus projection lens.
Lamp: 190-watt UHB.
Measured brightness: 1,579.16 ANSI lumens (average of wide- and narrow-zoom settings); 1,579.32 ANSI lumens in wide-zoom setting (Proxima specs list 1,500 ANSI lumens).
Measured ANSI contrast: 114-to-1 (Proxima specs list 100-to-1).
Connections: Two 15-pin data inputs with stereo-audio, plus one 15-pin monitor output with audio. One combined composite and S-VHS video input with stereo-audio input. Projector includes a USB serial connection for mouse control of presentations, along with a 15-pin control port that ProjectionLink uses.
Video compatibility: Accepts most popular video sources up to SXGA.
Speakers: Two 1-watt, built-in speakers.
Accessories included: Laser pointer IR remote control.
Proxima's latest mid-range "conference-room" projector, called the Desktop Projector 6850+, is an OEM product from Hitachi. I can't remember the last time I reviewed a Hitachi 1.3-inch LCD projector, but it doesn't really matter, because the Proxima DP6850+ is an extremely well-equipped projector that exceeds its specifications in all the important categories.
Proxima rates the DP6850+ at 1,500 ANSI lumens, but I measured an even more impressive 1,579.32 ANSI lumens in the wide-zoom setting, and an average between wide- and narrow-zoom lens settings of 1579.16 ANSI lumens -- which exceed Proxima's specs. The negligible difference in light output between wide- and narrow-zoom settings is also an indication of good lens design.
With the same contrast and brightness settings used to measure lumens, I measured the projector's ANSI contrast ratio at 114-to-1 -- slightly below average for a three-chip LCD projector, but still quite good, and above Proxima's stated spec of 100-to-1. I also quantified the white-black sequential contrast ratio and the DP6850+ measured 158-to-1 sequentially -- again a bit low, but hardly noticeable. The best new LCD projectors are getting contrast ratios close to 400-to-1, so I expect the next round of improvements in this projector will address that issue.
I measured the DP6850+'s color saturation at 15.8, a bit below the 16.2 color saturation average for a three-panel, x-cube-based system, but a lot better than the 13 to 14 measurements found on tiny one-chip DLP projectors. Besides decent color saturation, the projector's white point at 3.82 units away from standard D65 was also quite good. Unlike a lot of other projectors, the DP6850+'s images have great uniformity (only one percent variation across the screen) and excellent corner brightness. The projector had about 94 percent of peak still carried in the corners, which is much better than the average three-panel projector's 78 percent. As I have said before, the use of more optical integration elements provides better evenness and brighter corners -- but at the expense of the ANSI lumens. The DP6850+ has probably used about 200 lumens to smooth things out, but the projector is still bright enough that nothing is missed.
The Proxima DP6850+'s images with a DVD video signal also left little to be desired. The images had impressive color saturation, contrast and brightness with above-average evenness. Like a lot of LCD projectors that are optimized for computer graphics, however, the DP6850+ could use better color mapping. The video signals coming from a DVD player are designed around the SMPTE color scheme, whereas most LCD projectors are not -- and it shows. Other manufacturers, such as Mitsubishi with its ColorView Natural Color Matrix, do a better job than Proxima in this regard, and it's time for the company to catch up.
All the connectors -- power, data, video and audio connectors -- are on the right side and, unlike some projectors, the DP6850+ does not lack USB connectivity. Along with a USB mouse port, it has a 15-pin control port that can be used for many functions, including Proxima's latest invention, the ProjectionLink.
When Proxima first showed me ProjectionLink, I thought it was a kind of network system for projectors. But it is not a network. Even though ProjectionLink uses the same Category-5 cables and RJ-45 connectors most Ethernet networks use, ProjectionLink is actually just a long-run video and data signal-switcher system that allows you to send your video and computer signals as far as 300 feet to a remotely mounted projector, using only one Cat-5 cable -- a previously undoable feat.
The AC-powered ProjectionLink transmitter takes up to two computer RGB signals, along with two video signals in S-VHS, composite or component format (depending upon the projector) and sends the "push-button selected" video stream through one Cat-5 cable to the AC-powered ProjectionLink receiver. The receiver is connected to the projector through the standard 15-pin RGB cable plus S-VHS, composite or component video cables as necessary (if you don't connect, it won't project). In addition, the ProjectionLink receiver needs to be attached to the projector through an RS-232 cable to switch the projector between video and computer modes as required. The transmitter and receiver each require its own small AC power pack.
Why use Ethernet wires if it's not really a network system? Just to confuse people? According to Proxima, it's because Cat-5 cables are cheap and plentiful -- which means that it's possible to save a bundle on cabling using Projection-Link, because it isn't necessary to use more expensive BNC-5 HR (high-resolution) cables. Cat-5 cabling only costs about a $1 a foot at most; HR cabling costs about $4 a foot.
But people don't use Cat-5 cabling for a 300-foot long run for several reasons: Resistance over that long connection degrades the projector signal too much. Given the physics of this problem, I was skeptical about Proxima's claims that a simple Cat-5 cable could work as well as a thick BNC-5 cable, but I'm not skeptical anymore. The secret lies in the fact that Cat-5 cable consists of twisted pairs -- each pair is two wires that wrap around each other. As it turns out, both wires can be used to carry the video signal as well as provide a "shield" against interference. A BNC cable consists of one thin wire, insulated in the middle of a hollow conductive shield. A twisted pair can work about the same electrically as the wire-in-a-shield BNC cable, because Cat-5 contains eight wires -- four twisted pairs -- enough for the essential video signals: red, green, blue and clock.
Does ProjectionLink work?
If you do not make the mistake of trying to run the ProjectionLink signals through your network hub, the setup works just fine. I compared the ProjectionLink system using one transmitter and one receiver with 100 feet of Cat-5 cable to an Extron system consisting of two ADA 6 300MX six-channel distribution amplifiers connected with 100 feet of BNC-5 HR cable. Both the ADA 6 amplifiers (one used as a transmitter and one as a receiver to create the same configuration as the Projection-Link) were connected to the signal source and projector with the same short OEM cables as the ProjectionLink transmitter and receiver used. I then compared the image quality and measured the onscreen brightness when the exact same signal was run directly into the projector, through the ProjectionLink and then through the Extron ADA 6 system.
ProjectionLink vs. BNC-5 HR
Comparing the onscreen images, I thought the Extron-based system delivered a slightly cleaner-looking image; the Proxima ProjectionLink image had some residual "crawlies" that needed tweaking with the projector's phase adjust. I also found the ProjectionLink image was slightly brighter than the same image that went through two Extron ADA 6 amplifiers -- but that was because the ProjectionLink "boosted" the signal, a feature not found on the standard ADA 6.
The bottom line is I am now a believer that a Cat-5 cable system can work just as well as the thicker, heavier and considerably more expensive BNC-5 bundle. The cable thickness and weight alone will make it easier to install remote projectors, as will the signal-tweaking function found on Proxima's ProjectionLink. It also acts the way a one-channel switcher does so that video and data can go through one wire. One problem ProjectionLink doesn't address, however, is the multiple projector, multiple-source situation. Many installations (including my screening room) use several projectors at once, and until Proxima or someone else comes up with a Cat-5 based distribution amplifier that can handle the necessary control signals as well, we are out of luck.
In addition, ProjectionLink, at $1,599, is a little pricey for a system designed to appeal to those doing an installation on the cheap. But if you've got a spare Cat-5 cable in your building's wiring that doesn't hit a hub in between, ProjectionLink will drop right in.
Contact: Proxima Corp., 800.447.7692, www.proxima.com.
William Bohannon, chief scientist at Escondido, Calif.-based Manx Research (760.735.9678), has more than 25 years of experience in the computer and projector industry. As chief scientist for display products at Proxima Corp. from 1989 to 1994, he developed important business relationships with several Japanese laboratories and companies. His career also includes positions at TRW, Hughes Aircraft and Kappa Systems.