Hitachi PJTX100 UltraVision front LCD projector Calibration


For my bench tests of the PJTX100, I set up a battery of equipment to check out its performance with both composite and component video signals and PC signals. It took some time to cycle through the presets for Gamma and White Balance to arrive at a baseline combination I felt showed off the projector at its best, but once I had a good-looking gray scale with no crushing of blacks or whites, I measured the screen brightness as 512 ANSI lumens (Normal Gamma, Iris at "10," Black Enhancement Off).

By toggling through the different Gamma settings, I found that the brightness measured as high as 850 lumens in Dynamic mode. Activating the Black Enhancement settings dropped the overall brightness considerably. Going back to my baseline image settings and selecting Natural Black dropped the brightness to 248 lumens; switching to Deep Black chopped it even more, to 133 lumens.

The PJTX100 had good contrast for an LCD projector. With my baseline settings, the ANSI (average) contrast measured 224:1. Alas, this projector suffered from the same limitation as every other LCD projector: high black levels. The Black Enhancement settings attempt to overcome this, but the fact is that any shadow detail in a projected movie was simply lost in the washed-out dark grays. Dropping the black levels made that detail even harder to see.

If you're patient enough to fine-tune the Gamma and White Balance settings, you should get a very good gray-scale track out of the PJTX100. The measured color temperature varied by a maximum of 703 kelvins from black to white, drifting slowly up as the luminance level increased. That's extremely good performance for an LCD projector, and compares favorably with Panasonic's PT-AE500U.

In terms of bandwidth, the PJTX100 did much better through its analog RGB or DVI input. I measured picture detail out to 37.5MHz with a 720p test pattern, and a slight loss of detail at this frequency using a 1080i source. Through the analog component inputs, the frequency response was good to 18.5MHz with a 720p signal, and some filling-in was evident with the 1080i pattern.

Want to hook up your computer for gaming? The PJTX100 will quickly sync up to signals from a variety of notebook and desktop PCs, and it supports SXGA (1280x1024) and SXGA+ (1400x1050) resolution with intelligent pixel scaling. You might need to use the menu to tweak the horizontal and vertical image position and size to get them just right, though. —PP

[Because PP uses a white screen and I have an 80-inch-wide Stewart FireHawk, I spent a few hours with the Hitachi projector to provide an additional perspective. Set up for the best balance of brightness and contrast with the iris wide open (a setting of 10), and using the DVI input and custom gamma and color-temperature settings as the unit was received from PP, I measured a peak onscreen contrast of 892 (PP's lower contrast reading is an ANSI value from a 16-square checkerboard). At a full-field peak white (100 IRE) of 32.1 footlamberts without white clipping (and a video black level of 0.036fL), the Hitachi is one of the brightest projectors I have measured. It also has more than enough output for larger screens (though I strongly prefer this screen size for standard-definition material, including DVDs).

But this setting did not produce the best overall picture. I could get a substantial improvement by leaving the Contrast control at the maximum non-clip setting and reducing the Iris setting to 3. This lowered the peak white output to just over 13fL (close to the maximum I can get from most single-chip DLPs). While this change increased the measured peak contrast only slightly (to 948), it dropped the video black level by more than half, to 0.014fL. As PP correctly points out, the iris adjustment cannot improve shadow detail (if it isn't in the image before it hits the plane of the iris, the iris can't create it), but it did make the image more filmlike, and significantly reduced the foggy look in very dark, low-contrast scenes that afflicts most LCD displays we've reviewed.

Set up in this fashion, the Hitachi's shadow details were still a little murky, but even on a very dark DVD, such as Hellboy, this limitation never took me out of the movie. There was a slightly rosy tint to the mid-grays that I could not eliminate at any color-temperature setting below an unacceptable 9300, but I was never bothered by this on real program material—not even on the black-and-white DVD of the original The Manchurian Candidate. And while I didn't have the Panasonic PT-AE500U on hand for a direct comparison, I definitely feel that the Hitachi's higher cost buys you a worthwhile increase in performance.

The red, green, and blue color points were good: Greens were a little too deep and blues a little purplish blue, but the deviations were no more visible than with most other projectors we have tested.—TJN]

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