LEDs, if properly chosen, can also offer a wider color gamut than projection lamps. This will only be a benefit if the color gamut of the source matches that of the display. If it does not, it merely distorts the colors. But the Samsung offers service-level adjustments to dial in very accurate color points. "For more on this, see the "Tests and Calibration" section.

Tuning In
I did all of my serious Samsung viewing from either standard definition DVD, HD DVD, or Blu-ray. My preferred setup was a modified Movie mode. I did experiment briefly with Standard mode, modified considerably to produce a proper user-level calibration, just so I could experience the set's DNIe "enhancement." (DNIe cannot be engaged in Movie mode.) Be afraid. Be very afraid. It was only a few seconds before I returned in panic to my preferred, non-DNIe, Movie mode settings.

I normally don't use the noise reduction currently offered in most sets. The Samsung's noise reduction, at least in Movie mode, was less effective than most.

This set has a lot going for it, but let's get the problems out of the way first. With 1080i signals it did not respond to the maximum high frequency bandwidth of our test pattern generator (37.1MHz) in either HDMI or component (more on this in "Tests and Calibration"). It also exhibited some obvious pincushion distortion (inward bowing of vertical lines) at the sides of the image. This aberration was rarely visible on normal program material, but it's rare today to see it at all, whereas it was fairly common in the days of CRT dominance.

The overscan on the bottom of the image was a bit high, at 4% with both HDMI and component video. The set will reproduce below black and above white, and in the latter case I could crank the Contrast control all the way up to maximum in the Movie mode (100) without clipping the whites. While I suppose this is a desirable situation, it does make it more difficult to choose the optimum setting of the Contrast control. I chose to run it at 90 most of the time, which appeared to work just fine when the rest of the setup is optimized.

There was also a noticeable hot spot on the set's high gain screen, which isn't that unusual in commercial rear projection sets. Here, however, it extended across the screen from left to right. It was clearly visible on a screen displaying a full video black test pattern, but was never obvious to me on normal program material. Like most rear projection sets, however, the screen's brightness falls off noticeably as you move off-axis.

The on-screen adjustment menus do not drop out of the way when you select a specific parameter to change. That is, the full menu heavily obscures the screen image you are trying to use as a reference for making the adjustment.

But by far the most significant failing of the HL-S5679W is its black level. Calling it mediocre would be a positive spin. It's never less than watchable, and never descended into the murky blotchiness that passes for black on some sets (a failing that is thankfully less common than in early digital designs). Nor did the set exhibit any significant false contouring in dark (or bright) scenes. But the set's black level was higher than I have measured on several LCD flat panel sets, and LCD flat panels are not known for their great black levels.

Dark scenes with bright highlights fared reasonably well, but as soon as the scene was uniformly dim the Samsung's poor blacks produced a noticeable grayness—the proverbial gray fog. It never got so bad that I couldn't easily follow the action, but it was hard to ignore, nevertheless. Recent Samsung lamp-based DLPs have included irises that produce decent black levels, but the HL-S5679W lacks any sort of manual or automatic iris.

On to more upbeat topics. The Samsung might just have the most accurate color we have yet seen on any video display. It did not arrive in that condition (though its out-of-box performance in that regard was very respectable), but the service-menu adjustments provide a route to nearly dead-on accurate results for the experienced calibration technician.

The odd thing about the post-calibrated Samsung is that the colors do not jump out at you as being all that much better than other sets with reasonable, though not quite as technically pristine, post-setup results. But after a while you start to notice things that you hadn't before. The detail in a rusted gate in Charlotte Gray. The blue top of a French gendarme's hat in the same film. The natural skin tone of Johnny Depp's Willy Wonka in Charlie and the Chocolate Factory when he discovers the Oompa Loompas, in contrast to his pallor in the factory scenes. And more.

Add to that the set's deep but not unnatural reds, rich blues, and reasonably believable greens (still a bit Crayola-ish in sunlit scenes, though less so than in many other digital sets).

Despite its limitations at the maximum HD frequency as seen on test patterns, the Samsung produced surprisingly fine resolution on real-world material. Good standard definition DVDs like Charlotte Gray, Master and Commander: The Far Side of the World and Pirates of the Caribbean: Dead Man's Chest might fool the neophyte into believing he or she was watching high-definition. And HD transfers like Phantom of the Opera (HD DVD) and Kingdom of Heaven (Blu-ray) looked nearly as crisp and detailed as they do on far more expensive 1080p front projection displays.

Conclusions
Despite some reservations, I definitely enjoyed the time I spent with the Samsung. In particular, its cutting edge light engine, not to mention its adjustability, makes it one of the most unique sets on the market.

Still, it appears to me to be something of a work in progress. In an overall balance of virtues, there are lamp-based sets that can beat it (including presumably some of Samsung's own) for less money. They may not have its spot-on color, its potential savings in lamp costs, or, in particular, its immunity to those pesky rainbows. But they will certainly outdistance it in equally (or more) important qualities, in particular offering deeper blacks and a higher contrast ratio.

I suspect that we will see more than one new competitor to this set at the January 2007 CES, perhaps even from Samsung. The LED light engine is outstanding, and Luminous Devices just recently announced an even brighter version of the PhlatLight that be practical for use in even larger rear projection sets (but not quite yet, I suspect, for front projectors). Assuming the LED chip prices come down to competitive levels, the projection lamp may well become an endangered species, at least in rear projection sets.

Highs
Trend-setting color accuracy
Crisply detailed picture
Precise, but complex, service menu adjustments

Lows
Poor black levels
Some pincushion distortion
Common control settings are tedious to access in the on-screen menus