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Runco Q-750i Review

April 19, 2010 By David Birch-Jones

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Runco Q-750i Review
Runco Q-750i side
Runco Q-750i back
Runco Q-750i Spectrum

Dim bulb? How about no bulb!

Specialist video maker Runco QuantumColor Q-750i and Q-750d front projectors got a lot of attention at last year's CEDIA, as they’re the company’s first offerings that include a trio of high-output, light-emitting diodes that provide the light source, in lieu of the traditional high pressure lamp.

Runco Q-750i/Q-750dWhile not the first displays to feature LEDs as the light source (some now-defunct rear-projection sets that were similarly powered were available from vendors such as NuVision and Samsung), the QuantumColor sets are among the first in the front projector segment, and feature a number of enhancements that set them apart from traditional lamp-based models.

At launch time Runco offered two models, essentially identical in performance, but differing in video processing configuration.

The Q-750i features an integrated video processor, while the more expensive Q-750d is shipped with an outboard video processor that doubles as a video switching center. Both offer two different lens throw options, along with an optional external anamorphic lens setup.

Their InfiniLight LED engine features a trio of high output LEDs, one each to provide red, green and blue. LEDs offer a number of advantages over traditional lamps, not the least of which is tremendously increased lifespan. Conventional projectors use high-pressure lamps, which are essentially arc lamps powered by a modulated square wave signal. Their lifespan is limited, and while operating lifetimes have been on the increase (with some sets spec’d at 4,000 hours or more in the economy lamp mode), the actual lifespan of these bulbs is more often determined by the actual number of power on/off cycles, which means your mileage may vary.

Conventional lamps also suffer from deterioration over time, becoming somewhat dimmer toward the end of their life, and their color characteristics also tend to shift with age, perhaps necessitating multiple calibrations over their operating life. When they do decide to give up the ghost, they often don’t go silently into the night, instead choosing to go out with a literal bang, which can be quite discomforting to viewers who are in the middle of watching a movie, and in some cases necessitating a trip to the repair center. Replacements aren’t cheap either, usually in the mid-hundreds of dollars; much more in the case of deluxe models with super-bright lamps.

They’re also severely limited in their light output range, with only about a 20 percent variance in light level output possible. Unlike conventional incandescent filament bulbs, projector lamps must operate within a fairly tightly defined range, otherwise their operating lifetime is severely compromised.

Still another area where conventional projector lamps come up short of the ideal is their light output characteristics, which feature a “spiky” luminance response over the visible light spectrum, with sharp and narrow peaks that present challenges when it comes to displaying a smooth color gamut. And, with single-chip projectors (the most popular DLP type), the use of conventional lamps necessitates a spinning color wheel, which further adds to physical and electronics complexity.

Runco Q-750i Review

Conventional projector lamps also generate considerable heat, which must be dealt with, involving a fan (or two or three) and intake and exhaust air flow channeling. If a projector is to be mounted in a soffit or a hush box, care must be taken to ensure that the cooling system’s performance isn’t compromised.

All of these problems have been solved with the QuantumColor’s InfiniLight LED-powered light system. Their operating lifetime is likely to be in the tens of thousands of hours. Their combined spectral response is much less spiky, and more closely resembles the colorimetry of natural white. They can be switched on and off very quickly, which eliminates the need for a color wheel in single-chip DLP applications, and they can be dialed up or down over a very wide output range, which provides for a significant increase in dynamic contrast.

Although there might be some variance in the output characteristics over the LEDs’ lifespans, Runco solves that by providing automatic self-calibration. During start-up (which is a lot faster than with conventional bulb-powered projectors), the set activates an internal tri-stimulus sensor that checks the white balance of the LED light engine against an internal reference, and makes suitable adjustments in a split-second. The whole process is transparent to the user and happens in an instant, unlike a conventional calibration which can take two hours or more.

The QuantumColor’s energy efficiency is quite a bit better, compared to a conventional lamp-based model, boasting a substantial 70 percent reduction. The LED light engine doesn’t generate anywhere near the heat of a conventional lamp source, which will aid in placement versatility.

Clad in traditional Runco livery, the QuantumColor 750 looks not too different from their traditional bulb-based models, with a cabinet that speaks industrial no-nonsense styling. Both versions offer two significant advantages over other offerings, with the ability to “punch up” color saturation without destroying flesh tones in the process, as well as the ability to dial in individual color saturation levels via an innovative color equalizer.


Good review, but you missed the most important point...can it do 3Di?

Just kidding!

I love my Epson 7500UB, but I can't wait for this technology to trickle-down. I find the self-calibration especially intriguing.

We displayed the Q750 at The Sound Room in Chesterfield Missouri and were immediately impressed with not only the color quality, but the brightness and image detail are excellent as well. Thumbs way up!

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