Panasonic’s lightest-in-class DLP projector is a diamond in the rough.

The PT-D7600U runs on a pair of UHM lamps, reducing both cost and weight.

For that reason — and thanks to the premium that three-chippers add to the MSRP of an installation projector — three-panel LCD projector manufacturers have pretty much had the lower-priced installation market all to themselves for the past seven years. In particular, Sanyo, Eiki, Sony, Sharp, and NEC have been able to place lots of LCD projectors into facilities where the budget for “three DMDs and a xenon lamp” just didn't exist.

But all that has changed. The Panasonic designs have managed to cut both cost and weight by doing away with the xenon lamp, power supply, and large blower, replacing all of it with a pair of UHM lamps and running a smaller power supply. For added utility, Panasonic has made nine different lenses available in the most desirable focal lengths.

“Box” is a good description of the PT-D7600U. It's almost perfectly square, measuring 17in. on a side and 8in. tall. The base weight is 43.6lbs. before you add a lens, making the projector almost half the weight of comparable “small” DLP projectors using xenon lamps. There's not too much to see on this projector, either. It won't win any styling awards with its plain-Jane, off-white housing, but there is an easy-to-use keypad on the rear of the projector to enable local control. (See Figure 1.)

A rubber bib protects the front lens opening. To install the lenses, you insert them to match a keyed series of slots and protrusions, then twist into place and lock the lens. (Still photography guys call this a “bayonet” mount.) A small nylon connector attaches to the lens to enable motorized zoom, focus, and lens shift functions.

The input jack field is all business and supports every known analog video format from composite to component and RGBHV. The composite jack is a pair of BNCs, one of which is a video loop-through connector. The 15-pin d-sub VGA jack on RGB 2 can also function as a loop-through connector, configured from the PT-D7600U's menu. An expansion slot is provided for special purpose cards, such as a DVI input, SDI, or even HD SDI. (See Figure 2.)

The PT-D7600U provides both vertical and horizontal lens shift for off-axis projection, and you will have a tremendous range of adjustment. On a 100in. diagonal screen (60"×80"), I was able to pull the image a total of 60in. vertically and 50in. horizontally, using the supplied 1.5-2:1 standard contrast zoom lens (ET-D75LE1). This adjustment is done from the menu, not with a flywheel or thumb wheel on the projector, so the vernier adjustment is very smooth.

Other lens options include a super contrast (SC) version of the test lens and standard and SC variations in 2.0-3.0:1, 3.0-5.0:1, and 5.0-8.0:1 zoom ratios. For short throws, there's also the ET-D75LE5 fixed-focal-length lens with a projection throw ratio of 0.8:1.

If you are really into tweaking every little adjustment on a projector, the PT-D7600U has you covered. In addition to a signal auto-detect and clock sync function (which works very well, by the way), you will have access to full horizontal and vertical image shift and positioning, plus clock sync and phase controls. This projector will pretty much handle any computer video timing standard you can think of, and if it can't get the image right on, you can complete the job in the setup menu.

Figure 1 (top) Control keypad.

Image parameters are defined in five basic picture modes — Standard, Natural, Cinema, Graphics, and Dynamic. Within those menus, you will find 10 different gamma settings including the standard 2.2 and 2.5 tables, plus two of your own choosing. Panasonic has also provided auto noise reduction, picture enhancement (signal peaking), and a control marked “AI,” which seems to boost contrast.

Even though the light source is a pair of 300W UHM lamps, you can dial in a pretty close match to D6500 by using the projector's red, green, and blue bias and drive controls. Or, you can simply choose one of the preset color temperature combinations to match everything from D3200 (for use in conjunction with tungsten lighting) all the way to D9300. In RGB mode, you'll also be able to match 2,048 values of red, green, and blue primary colors as well as 2,048 cyan, magenta, and yellow secondary colors.

Figure 2 (bottom) Input jack field.

The supplied remote control has very good range, and its buttons are large enough to work without looking at them. You'll have direct access to any active input (no sequential input navigation here!), and dedicated directional arrows provide the navigation around and through menus. The supplied mousedisk is sloppy (as usual — when aren't they?) and is only for remote mouse operation.

The cooling fan is rated at 38dB noise when running in Low mode. But change to High mode, and you've got a hair dryer on your hands, so the PT-D7600U is best mounted in the ceiling near sound-baffling elements. It's just too noisy in High mode to be placed on a tabletop or even a roll-around cart.

For this review, I used a variety of RGB and video sources, including my trusty Diamond Viper 550 video card (runs up to 1280×1024 in 32-bit color), Extron's VTG-200 test pattern generator, DisplayMate for Windows test patterns, Sony and Panasonic DVD players for interlaced and progressive-scan video, and Samsung SIR-T150 and SIR-T151 DTV set-top receivers plus a JVC HM-DH30000U D-VHS for HDTV sources.

I chose to make all of my adjustments and measurements in Natural mode with both lamps enabled, the lamp Low function turned on (conserves power and the lamp runs quieter), and 2.5 gamma selected. With the supplied zoom lens set to its mid-point, I measured 1,664 ANSI lumens with ANSI (average) contrast at 152:1 and peak contrast at 204:1.

Those are not particularly high numbers for this projector, which Panasonic rates at 6,000 ANSI lumens in dual-lamp High mode. But the model I received had been around the horn a few times and was really considered a production sample. Selecting lamp High mode raised ANSI brightness to 2,088 ANSI lumens, and selecting Dynamic mode brought that up even higher to 3,347 ANSI. Average contrast didn't change much through these modes, and peak contrast actually dropped off due to higher black levels.

Brightness uniformity was not particularly impressive, measuring 62% average and 53% to the worst corner. That's bordering on hot-spot territory, and I would assume that Panasonic will fix the polarized beam splitter and associated optical components to get a better spread of light across the screen. (Before you ask, no, the PT-D7600U does not use Texas Instruments' “dark” 1280×1024 DMDs, only the garden-variety chips.)

The PT-D7600U does much better when tracking a grayscale, staying within 410 total degrees K from the low end to the high end. That's very good performance from UHM lamps (and, in fact, most short-arc metal halide lamps) and usually associated with xenon imaging only. This means you can get exceptional color quality out of the projector. Assuming Panasonic can improve contrast performance, this projector will have a significant edge over comparable three-panel LCD projectors that are hard-pressed to maintain that small a color shift.

The PT-D7600U breezed through this part of the obstacle course, getting 22 test signals set up correctly on the first try while skipping by three others (one being a 1600×1200 test pattern). You can also connect DTV and HDTV signals to the projector in either YPbPr or RGB formats, and it will recognize either. Although the projector didn't come with a DVI connector, I would assume the Panasonic accessory DVI card will also provide support for HDTV standards.

Given the PT-D7600U's 1280×1024 pixel native resolution, its toughest task would be to clean up and scale composite video input signals. It does this job surprisingly well with an excellent adaptive comb filter that leaves plenty of detail in Video Essentials Zone Plate 300-line and 400-line test patterns, and the projector's video signal processor picks up transitions from 3:2 material to 30fps video quickly — most of the time. Once in a while, you will see scan line artifacts as source material changes from film-to-video to straight video and back again.

The flag-waving sequence in Video Essentials did have more than the expected number of interlaced scan artifacts and was not as clean as my Panasonic RP56 DVD player with Faroudja FLI2200 processor. (How about a Faroudja expansion board for the PT-D7600U?) I found small objects in different video scenes to be somewhat obscured and soft, a common artifact with DMDs.

Switching to HD sources makes a big difference, particularly 720p source material, which maps 1:1 on the DMDs. You will see a softening on 1080i programming, thanks to a pixel decimation of 29% when re-mapping. In general, progressive-scan video will look best on this projector, but it needs more contrast in the images. The PT-D7600U has sufficient bandwidth in 720p and 1080i modes to pass an 18.5MHz multiburst pattern, but rolls off the 37.5MHz pattern a little.

The color quality in all modes is excellent, and the video decoders are quiet — not much noise or speckle is observed in scenes with deep blue or red colors. With improved contrast and lower black levels, the color palette would increase considerably. If that can be done, I see no need to obsess over using a xenon lamp — the color coordinates can be matched well to standard RGB color gamuts.

The PT-D7600U provided lots of pleasant surprises, but it left me wanting in several areas. It's really a work in progress and can only get better. Its performance with RGB images and progressive-scan video was very good, but it doesn't handle interlaced sources nearly as well. An outboard scaler or aftermarket plug-in video card should clean up these problems in short order.

You can be certain that if Panasonic succeeds with this breakthrough product, there will be a rush to come out with a me-too version. I expect to see OEM deals struck with Panasonic over the next year as other manufacturers sense a real opportunity to get three-chip DLP imaging into the systems integration mainstream. (And how long before we see a three-chip design using 1280×720 DMDs for high-end home theater?)