Runco D-73d 3D DLP Projector, Part 2

In Part 1 of this report on my visit to Runco to see the D-73d 3D projector up close and personal, I described its LED illumination and use of linear polarization to isolate the left and right images. Now, I'd like to discuss the alignment of its dual projection engines, its color features, and its outboard video processing.

With two projection engines, aligning their images on the screen is critical. The D-73d provides manual zoom, focus, and horizontal and vertical lens shift because manual adjustment of these parameters is more precise than motorized. This can get you pretty close to perfect alignment, but often not quite close enough, so one of the engines also provides an electronic warping function that finishes the job to within less than one pixel. That engine also exhibits a bit of electronic overscan in order to allow a range of possible warping, which causes some minor moire artifacts that are visible on certain test patterns but not on most real-world content.

Another problem with a two-engine system is that the precise colors of red, green, and blue are not identical between them due to slight but inevitable variations in LEDs of the same color. As a result, the focus is not exactly the same for all colors. There is a bit of color divergence on white lines, and the image is softer than a single-projector image when viewed very close up. But this was not evident on real-world material at a reasonable viewing distance.

For 2D material, you can use only one engine, in which case the projector is essentially a Q-750i (see Home Theater's review here). Of course, the light level will be cut in half, but this is the videophile approach in a fully light-controlled room. If you're going to host a football party, you can view 2D with both engines running for more light.

The D-73d has several interesting features with regard to color. First, it provides a selectable color gamut, including Rec.709, SMPTE-C, EBU, DCI (this is the first Runco projector to offer the digital-cinema gamut), and Native (the natural colors of the LEDs, which are very close to DCI).

Normally, I'd select Rec.709 and be done with it. But during my time with the projector, we switched between Rec.709 and Native with Runco Smart Color, which automatically adjusts the skin tones to look more natural—i.e., not sunburned—with the otherwise expanded gamut, and I have to say it looked really good, especially reds and greens. Yes, it's not what the content producers saw on their monitors, but it looked more realistic, especially since the colors are not shown at maximum brightness so they don't appear to glow.

Other color features include a Personal Color Equalizer, which is Runco's name for a complete color-management system that offers hue, saturation, and level controls for all three primaries and three secondaries as well as the white point. This is the correct way to design a CMS, though it is relatively rare. Runco's implementation of Texas Instruments' BrilliantColor overlaps the primary colors to create the secondaries, much like a RGBYCM color wheel, which brightens the secondaries and white.

Like most modern displays, the D-73d includes a dynamic-contrast feature called, oddly enough, Constant Contrast. (According to Bob Williams, Runco's chief product architect, this is short for Constantly Optimized Contrast, which seems a more accurate name.) This feature varies the current applied to the LEDs, dropping it in dark scenes. It did lower the black level, but as usual, I preferred watching real-world material with this feature disabled.

Along with the projector itself, the D-73d package includes three outboard units that combine to form what Runco calls its 3Dimension processor. HDMI from the source device is connected to a custom 3D processor, which separates the left and right signals. Each of those signals is then sent to its own DHD4 video processor—the one with a front-panel display is the Primary, while the other is the Secondary. Finally, HDMI from each DHD4 is sent to the corresponding projection engine.

The DHD4s perform all video processing, such as deinterlacing and scaling, as well as grayscale calibration, color management, and all other processing functions for each projection engine. They can be set so that adjusting one affects both equally (useful for initial setup and calibration), or they can be adjusted independently to tweak the settings for variations between engines and to warp only one of them. There are a lot of settings, which can be copied and pasted into the memories for different inputs without having to enter everything each time.

The processor can even accommodate an optional, motorized anamorphic-lens system called CineWide with AutoScope. Watching a stack of two Panamorph lenses slide in front of the primary lenses is pretty cool, and it worked quite well, as I'll elucidate next time, so stay tuned!