Projectors
Projector Screens
Most Popular TVs
Latest News
Runco QuantumColor Q-750i
They’re finally here: LED home-cinema projectors. Our first review features the Runco QuantumColor Q-750i, an absolute tank of a device that’s reported to cost 17,995 GBP in the United Kingdom and 14,995 USD in the United States. But what does the new technology have to offer?
Reviewed by Florian Friedrich on February 12, 2010
Great colours, adjustable colour temperature.
Extremely contrast-rich, uniform images.
Superb de-interlacing.
Long expected lifetime for the LED technology.
Excellent user manual.
Special lenses available to order.
Imperfect presets.
Loud fans.
Very expensive.
Impractical lens shift.
Lacks motion enhancement.
Slight colour fringing.
Limited brightness.
Runco’s brand-new Q-750i demonstrates that LED projectors can compete with the best in terms of picture quality — as long as you adjust the colours correctly. Besides the massive price, the noisy fan and limited brightness spoil the fun slightly.
The New LED Technology
And here they come: The first LED projectors are now finally hitting the market. The model we’ve reviewed here, the Runco QuantumColor Q-750i costs a proud 18,000 GBP — for which you’d easily be able to buy a car ... or maybe even two. So what’s so special about the new technology? By using red, green, and blue LEDs instead of traditional lamps the technology offers more intense colours, higher contrast, longer lifetimes, and higher energy efficiency.
Our review will reveal both the strengths and the weaknesses of the Runco. The fact is, however, that the American manufacturer is entering uncharted territory here, and it’s hard to compare the earliest products with fully developed conventional projectors — after all, existing devices deliver excellent picture quality and only cost a fraction of what the Runco does.
Features
As well as two HDMIs and two YUV inputs, the Q-750i can accept Scart-RGB signals via an adapter. Users can control the projector remotely via its RS-232 port.
The Q-750i uses DLP technology from Texas Instruments, and has no direct lamp cooling fan or colour wheel. But, at 30 decibels, it’s still astonishingly loud — louder, in fact, than most conventional projectors. There’s virtually no colour strobing, but the Runco struggles with other artefacts (see box below).
LED technology claims to offer significant increases in lamp lifetime: The LEDs are supposed to last for at least 50,000 hours of use, losing only 10 percent of their brightness over that time. That should be enough for four hours of viewing every day for over 30 years, but we’ll just have to wait and see if this is the case.
What we can already say is that LED lighting can switch on very quickly and — unlike conventional lamps — can be switched on immediately after being switched off. The user sets the focus and zoom manually, and the internal video generator provides 11 test patterns, including a green lattice with two-pixel-wide lines to allow you to focus the 1.3x zoom precisely.
|
LED Technology and Associated Artefacts The Runco uses reflective DLP chips from Texas Instruments but no rotating colour wheel. Nevertheless, it drives the DMD chip sequentially. In a lengthy optical path, prisms combine the three coloured beams from the LEDs and turn them by 90 degrees, sending them towards the mirror chip. Heat dissipating from the LEDs requires an elaborate cooling construction with heat exchangers, fans, and a hefty power supply. The result: The Runco is loud ... very loud! With an operating noise level of about 30 decibels, the American projector is far louder than its conventional rivals. On top of that, you also hear a quiet hum that varies depending on the picture contents if the automatic contrast adjustment is active.
The highly pure colour spectrum’s pronounced peaks for the primary colours red, green, and blue, are another of the special characteristics of LED technology — UHP lamps give a broader spectral distribution. This difference affects the way the projector’s lens produces images and can lead to colour errors in the viewers’ eyes. It’s therefore crucial that the lenses in LED projectors focus images accurately and can be adjusted precisely in order to avoid producing chromatic aberrations.
Four of our reviewers each perceived the colour fringes differently, but we were able to establish one consensus: The worse your vision, the more prominent the fringing becomes — a good pair of glasses or a shorter viewing distance will help. In moving images, you also see effects of the sequential RGB projection — we observed this on the spinning bar pattern from the “HD HQV Benchmark” test disc: If you stand directly in front of the screen, you’ll see a tiny colour fringe with the Runco, which wasn’t visible with the Samsung SP-A 800 B. From a distance of about one metre, the fringe isn’t visible on moving objects.
At the usual viewing distance, however, we noticed a colour fringe that gets stronger if you move your head or if the image is moving. It’s different on the Samsung, where no fringe is visible — colour strobing only appears when you move your head abruptly. LED projections barely suffer from this problem, but the slight RGB colour fringes appear more strongly in scrolling text (here we used the 100-hertz test from Peter Finzel’s “S.E.” test disc). Overall, despite its colour wheel, the Samsung produces fewer colour errors than the Runco.
|
The Runco’s optics produces a strange effect: If you look closely, you’ll see a reddish line around the edge of the white circle; this line does not appear with the Samsung reference projector. From farther away, you won’t notice this effect, but you will see blue-green lines as a result of refraction in the eye.
Operation
The remote control’s blue backlit buttons are clearly arranged, but the labelling is very small.
You can leave the installation to your Runco dealer — very handy. But there’s also a full colour-management system on board, whose settings are stored to two user-defined presets or (for isf-professionals) two isf presets (day and night). The device goes about its business pretty well, but the reviewed model sometimes failed to correctly recognize all of the connected signal sources. The user manual impressed us with some helpful explanations of the colour management, for example.
Colours, Light, and Contrast
Unlike UHP lamps, LEDs deliver a concentrated energy distribution with pronounced spectral peaks.
With correct colours (“Auto” colour space, “6500K” colour temperature setting), the reviewed model produced just 400 lumens — which only suffice for a two-metre-wide screen. At 192 watts, the power consumption is barely lower than that of conventional projectors. If you switch on the automatic contrast adjustment, the LED output drops in dark pictures and drastically cuts the power consumption — to a record-breaking value of 66 watts. In dark scenes, this three-level adjustment reduces the LED brightness dynamically to less than a tenth. This results in the maximum On/Off contrast increasing to 25,000:1, although this produces some slight side effects (see box below).
Switching on the “SatCo” function gives a brighter projection (504 lumens). But there’s a disadvantage: The power consumption climbs to 230 watts. This mode also has such weakly saturated colours that we haven’t even considered it in this review. The fact is: The model we tested failed to produce the 700 lumens that Runco promised, and remains less bright than conventional projectors.
The Q-750i’s ANSI contrast, on the other hand, sets a new record at 620:1. If you look into the optics, you quickly see that the outer areas of the lenses produce barely any scattered light. The in-picture contrast of 2,000:1 is also impressive — until now, only a few DLP projectors have achieved values this high. LCD and D-ILA models, however, can produce even higher values.
In our jet-black test theatre, the excellent DLP contrast gives an outstanding picture impression if you set the gamma to 2.35 instead of 2.2. But the “6500K” colour-temperature setting shows an unpleasant cyan tint in whites and greyscales. If you select 5,500 Kelvin instead, a slight yellow-green tint appears, although you can remove this again using the RGB controls. The colour-management system also allows you to optimise the slightly extended colour space.
The 1.3x zoom resolves test patterns excellently in the centre of the projection, but coloured fringing appears around the edges.
The optics collects plus points for its excellent focussing and sharpness. The edges of the picture often show red fringing, but this won’t bother you at normal viewing distances.
|
Dynamic Contrast on the Q-750i The “ConstantContrast” function dynamically increases the contrast in dark scenes. In black images, the Runco reduces its power consumption by up to 70 percent, and simultaneously adjusts the video signal to compensate for the loss in brightness. Such technologies can — depending on the video sequence — result in brightness pumping and reduced brightness in gloomy scenes. If the gamma and contrast compensation in the video signal are too strong, the differentiation will suffer. A good example is the test image of a red rose on a black background: With “ConstantContrast” activated, the leaves lose differentiation. In any case, you can confidently switch the technology off — after all, the projector has a massive native contrast ratio of 2,000:1 and the highest ANSI contrast we’ve ever measured.
In addition, the projector’s developers have included a setting for adaptive contrast adjustment. This automatically adjusts the contrast and brightness in scenes that don’t use the full dynamic range — and applies to both bright and dark scenes. The function increases the rose’s brightness without causing a loss of differentiation. At the same time it turns greys to blacks but, in doing this, slightly clips the darkest greyscale levels. This function is best suited to TV signals, which broadcast with different degrees of picture contrast.
|
“ConstantContrast”: The distorted gamma curve means the picture below loses detail and differentiation, even in the lowest setting.
Picture Quality of Standard-Definition Signals
The video processing even displays superb results with composite and S-Video signals: The colour resolution and picture sharpness are both consistent. Thankfully, you can switch off the picture cropping (overscan), as well as choosing between “Zoom” and “Crop” settings. The YUV input is sharper yet, and the de-interlacing makes an especially positive impression: It flawlessly recognises film and TV signals and converts them into flicker-free progressive video. With some DVD and TV material, the tested model’s de-interlacing was of even higher quality than that of the input device.
|
Optimum Settings for Colours and RGB Values LED projectors with no colour correction exhibit an extremely extended colour space. In the “Auto” colour-space setting, however, the Runco’s colours already match reds and blues well — it’s only with greens that the coordinates don’t match exactly. The colour temperature, at 7,300 Kelvin, is a bit too cool, and the picture shows a slight cyan tint.
The “Personal Color Equalizer”, a colour-management system, allows the user to set the tint, saturation, and brightness for primary and secondary colours. On top of that, the RGB menu allows colour-temperature adjustment. In the tested model, the following values gave precise colours and a neutral colour temperature of 6,500 Kelvin, but bear in mind that they can only act as a guideline, since manufacturing variations can affect the device’s performance.
|
The user-defined preset’s CIE diagram shows correct colours and an ideal colour temperature of about 6,500 Kelvin across all greyscales.
Picture Quality of High-Definition Signals
Via its two analogue YUV inputs, the Runco only recognises HD video in 720/50p format; 1080i-format signals produce an error message. Via HDMI, 1080i signals show occasional jumpiness. The perfect de-interlacing impresses once again, and you never need to change the film mode — the projector handles TV documentaries, films, and even 1080/30p signals with ease. Not even an especially tricky test scene (a girl’s face gliding slowly across the screen) can trip the Runco up: The girl’s eyelashes show no line flicker at all. Very few projectors perform this well. The fine beads of sweat on her face look a bit too sharp in the factory sharpness setting (100); if you turn the sharpness down completely, faces look significantly better.
Progressive 1080/60p video and 24-hertz signals both display perfectly. The “DLP Frame Rate: 48Hz” setting applies an “Inverse Telecine” function: NTSC films arriving at 60 hertz are relieved of their 3:2-pulldown judder and display just like 24p Blu-ray films at 48 hertz. It takes a moment for the function to get into gear, but when it does, it works excellently.
During a comparison with our reference projector, the Samsung SP-A 800 B, we switched off the Runco’s automatic contrast adjustment in order to produce a projection of comparable brightness. We chose the James Bond Blu-ray “Casino Royale” as our test disc. The Runco’s factory-preset colours are correct, but the greyscale reproduction shows some shortcomings. In the almost black-and-white opening scene, the LED projection looks a bit too cool because of a cyan tint, and yellows and ochres show a green tint during the opening credits. The sunlight on the airstrip looks artificial, as do the sea and sky.
It’s possible to tease impressive quality out of the fine-tunable user-defined setting — the blue-green tint is quickly eliminated, for example. But you need measurement devices to get truly optimal colours. The effort is worthwhile, though, and means the Runco can match our reference projector in nearly all disciplines. Its colours look natural and well saturated; reds are particularly intense and convincing. When the Samsung is in its eco lamp mode, it lags slightly behind the Runco. When the Samsung’s in its high lamp mode, the larger red components in its UHP-lamp spectrum mean the two devices are absolutely level. Here, though, the Samsung’s pictures are significantly brighter than the Runco’s.
In terms of depth and subjective contrast, both projectors impress: Their high ANSI and in-picture contrast ratios make for fascinating pictures in the dark home cinema. The Runco manages to produce uniform illumination right up to the screen’s edges, and its fine DLP pixels produce an extremely cinematic picture. In fast movements, however, the one-chip DLP technology reaches its limits — modern LCD and D-ILA projectors display camera pans more sharply. Colour fringes also occasionally appear in slow movements on the Runco. Still, the Samsung cannot avoid producing colour-strobing effects during very fast motion — and these are significantly less pronounced in LED projections.
Ideal Settings
Memory: Custom
Brightness: 104
Contrast: 100
Sharpness: 0
Gamma: 2.35
Color Temperature: 6500K
Color Gamut: Auto
SatCo: Off
ConstantContrast: Off
RGB Adjust: see box above
These settings apply to realistic playback of HDTV/Blu-ray material through the HDMI interface in a darkened environment. Manufacturing and HDMI playback device deviations might necessitate slight adjustment.
If you want to share your opinion on this projector,
please reply to the thread accompanying this review on avsforum.com.
Digg
del.icio.us
Reddit
Google