PRODUCT REVIEW: DECEMBER 5, 2007
Panasonic PT-D5700U DLP Projector
Panasonic’s PT-D5700U is a versatile performer with plenty of zip in its light engine.
It seems that HD is all the rage these days; from the plasma and LCD TVs I’ve tested recently to the computer monitor I’m using and a few home theater projectors that have been reviewed here in the last couple of months.
Yet there’s still a market for lower-resolution front projection, particularly in the corporate, education, and house of worship markets. And the sweet spot for resolution seems to be divided between XGA (1024x768) and SXGA+ (1400x1050), both of which are 4:3 aspect ratio image formats.
Figure 1. The PT-D5700U’s no-nonsense design includes a white cover plate, suitable for stacking.
Panasonic’s PT-D5700U represents a different approach to the desktop/installation projector category. It has a dual-lamp design, a large housing with lots of airflow, motorized lens functions, and a full rack of analog and digital interfaces. Yet it also has some pretty sophisticated color management features and built-in edge blending options, not to mention a LAN interface for remote monitoring and control.
OUT OF THE BOX
This isn’t a small projector, as it measures nearly 21 inches by 17 inches by 7 inches. It also has two large cooling fans that take up 2/3 of the rear panel, pushing all of the video connections to one side. The top is as flat as a pancake, though, which makes it a snap to stack or mount the projector just about anyplace.
There aren’t any control buttons on top to worry about, either. They’re situated on the right rear of the projector, out of harm’s way and easily accessible in a stack. Go around the corner and you’ll find a full jack field, including one each composite and S-video inputs, a 5xBNC jack field for RGB and YPbPr connections, a 15-pin D-sub VGA jack which is also dual-format, a 15-pin loop-through connector, and a DVI-D input jack.
Below those, Panasonic has included 1/8” mini jacks for external wired control with a loop-through, along with a 9-pin remote control input. There’s also a conventional RS232C port with lop-through for controlling more than one PT-D5700U. And of course, the LAN connection is available for TCP/IP control.
Figure 2. Here’s the connector complement.
The PT-D5700U is available with and without a lens (PT-D5700UL). The review unit came with a 1.8 – 2.4:1 zoom, which works out to a 1.0 — 1.32:1 ratio. With a projection throw of 8 feet, I measured maximum image width at 55 inches and minimum image size at 41 inches. You can shift that image 50% vertically with a powered lens shift, or 25% to either side with a mechanical lens shift control on the front of the projector. There are also five accessory lenses available, from an ultra-short .8:1 prime type (ET-DLE050) to a long-throw 4.7 — 8.9:1 zoom (ET-DLE410).
The core imaging device is a .7” DMD with resolution of 1024x768 pixels, and it’s illuminated by a pair of 275-watt UHM-type short arc lamps. These lamps can operate simultaneously, individually, and in high and low power modes. An internal lamp relay function can switch from one to the other after a pre-determined number of operating hours have passed.
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Figure 3. The supplied remote is simple in design and very user-friendly.
REMOTE AND MENUS
The supplied remote control is about the size of your hand. It provides direct access to each of the five inputs, which should be mandatory for every remote control ever made. You’ll also find three buttons for power lens functions (Focus, Zoom, and Shift) below the menu navigation disk. The lens shift button only works in the vertical axis, as mentioned earlier.
There’s also a mechanical light shutter button that clamps down on every last photon when you want the image muted. The aspect ratio button lets you choose between six different modes (4:3, 16:9, S 4:3, H Fit (full width), V Fit (full height), and HV Fit (zoom to fill screen). There’s also an Auto mode that chooses aspect ratios based on pixel clock information. An Auto Setup button near the top will generally give you the right results after a few seconds of syncing up.
There are a multitude of functions in the menus that staging companies and large venue projectionists will love. In addition to basic image adjustments, Panasonic has provided five image presets (Dynamic, Graphic, Standard, Cinema, and Natural) and three color temperature settings (Default, Middle, and High). You can fine-tune color temperatures with 0-255 values of red, green, and blue for both contrast (high) and brightness (low) parts of the grayscale.
Dynamic mode will give you the flat-out brightest images with no color correction to speak of. Graphic, Standard, Cinema, and Natural aren’t quite as bright and would be used for more photorealistic images. As is the case with many DLP projectors, you can boost whites with 10 steps of white enhancement (the factory setting is 10), or leave it off altogether. This control allows for more “hits” on the DLP color wheel white segment during each pulse-width modulation time interval.
Additional image tweaks include three steps of analog noise reduction (plus off), a two-step AI control that is supposed to tweak image gamma, although it didn’t appear to do very much when I tried it, and a “digital cinema reality” option that (to quote the manual) “…increases the vertical resolution when the S-video/video signal input or 480i, 576i, 1080/60i or 1080/50i signal input is applied.”
Apparently this control is nothing more than a “Film” mode selection for detecting and correcting for 3:2 pulldown. When switched in Auto mode, it works just fine. However, it had no effect in 30p mode. It was also able to detect some of the Realta HQV oddball cadences, but not all of them.
On to the advanced menus. If you want control over color, you’ve got it with three different menu selections. The first (Color Matching) provides luminance value settings from 0-2048 levels for three colors (RGB), seven colors (RGBCMY and white), and a Measure mode. Here you can step through full-screen solid color patterns and take measurements for application to another projector, or apply measurements you’ve taken elsewhere.
In the “Measured Data” mode, you can set x,y coordinates and luminance for white, black, and three primaries. In “Target Data” mode, you can set those parameters for all six colors, plus white. (Note that you can’t shift the hue (phase) of any color in the 3-color or 7-color Color Matching modes.) With an accurate colorimeter, you will be able to match two or more PT-D5700Us quite easily in the Measure and Target sub-menus.
One additional control lets you increase or decrease the saturation of RGB and CMY colors, but not hue. I’d advise leaving this control alone and do the calibration correctly with a calibrated instrument.
Additional menu settings include a two-mode EDID setting (consumer DVI-D or PC DVI-D), DVI Black and Grayscale (0-255 or 16-235), and a three-step System Daylight View control that kicks up brightness and contrast to compensate under high ambient lighting conditions.
I mentioned edge blending earlier. The PT-D5700U has a comprehensive edge-blending menu that lets to define the overlap along the top, bottom, left, and right edges of the frame. You can increase or decrease the number of pixels across the image join and change brightness at that join to compensate for variations in brightness uniformity.
The LAN interface is standard and you can connect using DHCP to a PC or network, or assign your IP address manually. With a standard Web browser, you can control almost every projector function that’s accessible from the remote control.
A Monitor menu lets you keep tabs on conditions that include lamp life, lamp status, input status, three different temperature monitors (intake, internally, lamp), and elapsed hours of operation. An error notification and logging page, plus email notifications, round out the LAN functions.
Figure 4. The PT-D5700U tracks a tight grayscale at any color temperature.
ON THE TEST BENCH
After calibration for best grayscale image, I measured image brightness in Standard mode at 2959 lumens with White Boost set to +5. Both lamps were running normally and the zoom lens was set to its midpoint (about 2.1:1). Brightness ranged from a high of 5593 lumens in Dynamic mode to 4665 lumens in Graphic mode, 3545 lumens in Cinema mode, and 3496 lumens in Natural mode.
Switching to the Lamp Low/Dual option dropped brightness to 2275 lumens in Standard mode, with a further reduction to 1124 lumens with a single lamp operating normally and 689 lumens with that same lamp running at low power. That’s quite a range! Brightness uniformity across the screen was excellent, measuring 94% to the average corner and 77% of center brightness in the worst corner.
The PT-D5700U’s white balance is very consistent across an image, shifting by just 114 Kelvin from highest to lowest readings. That’s very important when edge-blending images, as a noticeable shift will call attention to the seam no matter how well the overlap is defined.
Contrast measurements were lower than I would have expected for a DLP projector, given the rich blacks that DMD light engines usually produce. In standard mode with white boost set at +5, I measured ANSI (average) contrast at 373:1 and peak contrast at 549:1. That’s because the level of black on the PT-D5700U is noticeably higher, similar to that of an LCD projector.
Contrast readings with a 50/50 black/white test pattern were 367:1 in Cinema mode, 350:1 in Natural mode, and 358:1 in Graphic mode. Switching to Dynamic mode, I took a reading of 459:1, which was my highest contrast measurement. Pushing the white boost all the way to 10 gave me brighter images, but contrast readings (363:1) didn’t improve any.
Figure 5a-b. The plotted gamma curves for Dynamic mode (above) and
Standard mode (below) reveal a tradeoff — white crush with high brightness levels.
The PT-D5700U tracks an exceptionally clean grayscale, as seen in Figure 5. I used the color temperature settings to D6500 with a 50% gray window, and that color temperature didn’t vary by more than 137 degrees from 20 IRE to 100 IRE. That means you can get some really accurate colors out of this projector when projecting video and film content.
But there’s a catch. (There always is!) The gamma curve in every mode resembles an “S”, which means that white details are being crushed. The result appears to be hot spots on bright objects and shiny areas on people’s complexions. The only way to fix this is to (a) turn white boost off, and (b) set the contrast control to its minimum level (-31). Only then will you see a more acceptable gamma curve — but your images will be considerably dimmer as a result.
Figure 6 shows the projector’s plotted color gamut. It’s very close to that of the ITU BT709 color space and also SMPTE-C. It’s possible to expand on that gamut with the various color adjustments, but the limiting native resolution of this projector makes it a poor choice for HDTV and digital cinema applications.
Figure 6. Here’s the plotted color gamut for the PT-D5700U,
which is very close to the ITU BT709 standard.
VIDEO IMAGE QUALITY
The supplied lens has very good image sharpness in both axes and minimal flaring, plus only the slightest hint of pincushioning as it is zoomed in and out. That means you’ll see plenty of detail in computer images, provided you limit your working resolution to 1024x768.
Given the fact that all new notebook PCs have widescreen LCD displays with at least 768 pixels, there will be a bit of pixel decimation when connecting one of these to the PT-D5700U, as horizontal resolution must be compressed. And it would seem that not as many desktop systems are using XGA these days, given the proliferation of widescreen, high-resolution LCD monitors in use.
With that in mind, I can say that graphics and fine text are readable on this projector with resolutions as high as 1280x1024. There’s plenty of contrast and snap to these images, too. Panasonic doesn’t specify compatibility with signals any higher in resolution than SXGA and WXGA, but I was able to get the projector to sync up to UXGA-75 (1600x1200 @ 75Hz) with no difficulty.
Video images looked best when connected from digital sources. Stay away from composite video as the projector has minimal capability to deinterlace and clean up the resulting artifacts, not to mention cross-luminance and cross-color schmutz. Component interlaced video is acceptable, but progressive sources make a big difference in image quality.
Off-air broadcasts in 720p and 1080i scale well as letterboxed images, so you should feel confident to mix graphics and HD video in a presentation, provided you are aware of the S-curve gamma issue that will tend to wash out highlights. Scaled red-laser DVDs show very well if brought in at 720p resolution, by the way.
CONCLUSIONS
From an end-user standpoint, the PT-D5700U gives you control over every projector you’d want to have, and should be very popular for staging and large venue applications. For graphics, photos, spreadsheets and Powerpoints, it is blazingly bright with good contrast.
However, for showing video and film transfers to their best advantage, the projector needs to be tamed quite a bit and you will sacrifice brightness as a result, something you’ll need to take into consideration if you are planning to use this projector in seamless panoramic mode for showing a mix of media.
