- Written by Chris Eberle
- Published on 16 September 2010
Since the first LCD units were pressed into service as home theater displays, digital projection has suffered from one limitation, the bulb. No matter the technology – DLP, LCoS or LCD – all digital front projectors use either a UHP (Ultra High Pressure) mercury or xenon lamp as a light source. This presents several obstacles. First, the lamp has to be replaced every so often. It can last as much as 4000 hours but sometimes it’s as little as 1000. Secondly, the lamp shifts color and dims as it ages. In fact, I will usually replace mine at 1000 hours regardless of the rating due to the lowered light output. The color shift also requires re-calibration at regular intervals. I always recommend adjustments at 100, 400 and 800 hours to maintain the most accurate image. Third, lamps run hot requiring a constant-running cooling fan to keep the projector from overheating. There must be a better way.
- Design: Single-Chip DLP Projector with LED Light Source
- Native Resolution: 1,920 x 1,080 at 48, 50, or 60 Hz Refresh Rate
- Light Output: 700 Lumens, 29 Foot-Lamberts
- Anamorphic Lens Support
- Throw Ratio: 1.17-2.40 Depending on Lens (6 Available)
- Lens Shift: Vertical ± 60%, Horizontal ± 12.5%
- Inputs: Two HDMI 1.3, Two Component, One S-Video, One Composite, 1 PC (D-Sub)
- Control: RS-232, 2-12v Trigger, IR input
- Rated LED Life: 50,000 Hours
- Dimensions: 10.2" H x 20.9" W x 22.5" D
- Weight: 49.4 Pounds
- MSRP: $14,995 USA
Enter the Light Emitting Diode. At last year’s CEDIA Expo, LED projection was THE hot new technology for high-end theaters. The promise of a product with a 50,000 hour lamp life is one of the most significant advances in front-projection since the invention of the DLP chip. With LED technology, projectors can now be used as the primary display. There’s no waiting for warmup or worrying about power on/off cycles and its lifespan is equal to a flat panel TV. Not only that, the light level and color will remain stable for the life of the product. Is there a catch? Read on as we explore this potentially revolutionary technology.
The Q750i is one of the largest projectors I’ve ever had in my theater. I am convinced there are now two things that will survive a nuclear holocaust, cockroaches, and the Runco Q750i. It is literally built like a tank. A silver trim piece extends across the top of the chassis from front to rear and drops down to create a lens bezel. This part is made entirely of cast aluminum. When I removed the front portion to access the lens shift controls, I was shocked at how heavy it was. I’ll bet it adds at least ten pounds to the overall weight. With a total heft just shy of 50 pounds you’ll need a sturdy ceiling mount for this unit. The rest of the case is stamped steel and painted with a light-absorbing black crackle finish. I couldn’t help but be reminded of the valve covers of my Dad’s 1967 Ferrari he had when I was young. The rear appears to be devoid of inputs until you realize the entire back of the projector is a door which flips downward to expose the jack panel. Inputs are recessed about three inches and the cables drop out a large hole in the bottom. Inputs include: 2 HDMI 1.3, 2 component, 1 S-video, 1 composite, and 1 PC (D-sub) with RS-232, 2 12v trigger, and an IR input for control.
The big news here is of course the LED light source. I am convinced this will be the next revolution in projector technology. The advantages are many. First, there is no bulb replacement necessary as the light engine in the Q is rated for 50,000 hours. At ten hours per day, seven days a week, you’d get over 13 years of service! Secondly, the light source does not dim or change color with age. Runco estimates a modest ten percent reduction in light output over the life of the product. Traditional UHP lamps can lose half their brightness in only 1000 hours. They also exhibit a color shift requiring recalibration every few hundred hours. Another plus is a lower operating temperature. The Q has only two small fans to cool the light engine. In normal use, they are essentially silent. The LEDs also allow a very wide color gamut. Not only does it encompass Rec 709, you can have DCI or an even wider gamut if you wish. The Native option is 135% larger than NTSC. LED also has more precise spectral properties than UHP lamps. I’ve included charts below that show the difference.
This spectral plot is from a Runco LS-5 with a mercury lamp and a native Rec 709 color gamut. Notice the wider peaks at the primary colors and the red deficiency. This color inaccuracy must be compensated for by the color wheel and the projector’s software.
The primary colors are output at much narrower and more precise wavelengths from the Q750i’s LED engine.
Like all DLP projectors, the Q750i employs dynamic contrast controls. Without these features, black levels and overall contrast would be less than ideal. Normally this is accomplished with a mechanical iris but the Q has none. Instead, variations in brightness are made by adjusting the LEDs drive voltage. This type of control is not possible with the slow response time of a traditional bulb but an LED can vary its output level many times per second. This allows frame-by-frame adjustment based on image content. The result is a wide dynamic range without the usual artifacts associated with an iris.
For those concerned with power consumption, the Q draws a maximum current of 140 watts. This is far below the 200-plus watts consumed by the average lamp-based projector. LEDs also require no warm-up time. Within seconds, the image appears at full brightness. Power-down is equally quick with no fan cycle after you’ve pressed Standby. And you won’t have to worry about shortening lamp life with frequent power cycles. LEDs do not degrade from this the way lamps do. Lastly, and this might be the most important factor to some, there is no color wheel in the Q750i. Since color is provided by the light source itself, there is no need for it. Those of you that experience the rainbow effect will not see it from this DLP.
The remote is very functional and contains all necessary controls. It is fully backlit with a pale blue color that serves to reduce eyestrain in dark environments. It is also extremely powerful. I was able to bounce commands off any surface in my room and the projector responded every time. At the top is a backlight button and discrete power keys. Next are individual source selectors. The three buttons labeled HD1, 2 and 3 can be assigned to any available input. Menu navigation is next with an Info key that brings up signal data and software version numbers. In the center are direct-access buttons for brightness, contrast, color and tint; and four buttons to select a picture mode. These modes can be set up any way you like and saved to a memory slot. The ISF modes can only be programmed with a passcode. Further down are aspect ratio keys and a numeric pad. The final three buttons labeled Focus, Zoom and Lens are not used with the Q750i model.
The menu system is very similar to the LS-5 I reviewed a few months ago. There are six menus starting with Main. The first option is Aspect Ratio with 16:9, Letterbox, 4:3, Virtual-Wide (non-linear scaling), Cinema (for anamorphic lenses) and Virtual-Cinema (non-linear stretch for anamorphic lenses). Next you’ll find basic picture controls like brightness, contrast, color, tint, sharpness, and noise reduction. You can also access the memory controls to save settings in one of two slots accessible from the remote. There are also ISF Day and Night modes available with an entry passcode. These memories can be locked to prevent changes. The next option, Overscan lets you either crop (mask) the image by three percent or zoom it out to 106 percent. Source Select lets you choose from any active inputs. You can eliminate unused ones if you wish. PIP Select allows you to see a picture-in-picture representation of two sources simultaneously. Resync will reacquire the signal if the image becomes unstable for any reason. This never happened to me.
The Advanced sub-menu has choices for Color Space (Auto, Rec 709, Rec 601, RGB-PC and RGB-Video). This is actually the decoder matrix and I was able to leave it on Auto. There is a separate control for gamut selection that allows you to choose between Auto, Rec 709, SMPTE-C, EBU, Native, DCI (Digital Cinema Initiative), and PCE (Personal Color Equalizer). If you want to access the color management system, you must select PCE. The gamma presets are 1.8, 2.0, 2.2 (default), 2.35, and 2.5. Color temp presets are 5500K, 6500K, 7500K, 9300K.
Moving lower in the Advanced sub-menu, you can choose a frame rate of either 48Hz, 50Hz, 60Hz or Auto. Auto will lock onto the incoming signal displaying 24p material at 48Hz and 60p/i material at 60Hz. This worked perfectly and I never saw even a hint of flicker at 48Hz from Blu-ray discs. The next three controls are labeled SatCo, ConstantContrast and Adaptive Contrast. SatCo boosts gray and secondary color levels to provide a little more punch. ConstantContrast widens the dynamic range by varying the LED’s light output to increase perceived contrast. Adaptive Contrast also widens the dynamic range by pushing levels to minimum black and maximum white regardless of the input signal. In practice this creates a very contrasty image but highlight and shadow detail are sometimes crushed. This might be useful in environments with some ambient light. Next are the RGB gain and bias controls. There is a huge 200-step adjustment range for these but I only had to tweak them a little to achieve accuracy. Fine Sync allows you to shift the image digitally and adjust phase, tracking and sync level for analog signals. The final menu is PCE which is the color management system. This menu is divided into Hue, Saturation and Level sections. You can turn Runco Smart Color (RSC) on or off and there is another White Balance menu for fine tweaks to the grayscale.
The System sub-menu starts with Input Enable which lets you deactivate unused inputs. PIP Position gives you options for the picture-in-picture layout. You can set up a split screen here if you wish. Next up are Menu Position and Translucency; self-explanatory. Blank Screen lets you choose a no-signal screen color of black, white or blue. Auto Power Off will shut down the LS-5 after a 20-minute no-signal condition. Auto Power On will turn on the projector whenever AC power is present. This is really cool because it allows you to power up using a wall switch if your outlet is so controlled. Rear Projection and Ceiling Mode change the image orientation for different installations. Logo Display turns the startup splash screen on or off and Power On Chime turns on a short beep whenever you power up.
The Control sub-menu lets you program the functions of three of the input selector keys on the remote. These can be set to any of the Runco’s seven inputs. The two trigger outputs can be set to fire on power-up or when different aspect ratios are chosen. The triggers can alternately be controlled by the RS-232 interface if you wish.
The fifth and sixth sub-menus are Language and Service. Language gives you a choice of eight languages for the menus. Service is mainly an information screen with values for Active/PIP Source, Pixel Clock, Signal Format, and H/V Refresh Rate. Here is where you can view the projector’s serial number and software version. Controls include a factory reset, blue-only mode, high-altitude mode for greater fan speed and test patterns. The patterns consist of full-fields for all colors plus white, an ANSI checkerboard, a gray ramp and a focus grid. One cool thing I discovered – the factory reset won’t erase the memory slots. That way, you can’t accidentally hose your settings as long as you’ve saved them first.
With the generous vertical lens shift available, I was able to install the Q on my shelf rather than inverting. Shift controls are hidden beneath the front trim piece surrounding the lens. Runco includes the appropriate Allen wrench to adjust them. Zoom and focus controls are manual using rings around the lens. While I do prefer these settings to be motorized, I was still able to throw a sharp image with correct geometry. It just took a bit longer t achieve. The four feet are independently adjustable so you can easily level the projector to the screen if it sits on a shelf or table. Ventilation is side-to-side so if you use a hush box, it only needs side openings.
Calibration can be a simple or complicated affair depending on the level of precision you’re after. Out of the box, the color is within a whisker of correct and the grayscale, while a touch red at the 6500K setting, is perfectly watchable. Being the obsessed tweaker that I am, and the fact that I find display calibration to be a somewhat zen activity, I went for that nth degree of performance that I know the Q is capable of. I only had to add a few clicks to the default brightness control and the contrast was lowered to 20 from its default of 100 to give me a peak output of 14.5fL. Gamma was spot-on at 2.2 so I turned to the RGB Adjust menu, which has gains and offsets for each primary to set up perfect grayscale tracking.
To access the color management system, you must first change the color gamut to PCE (Personal Color Equalizer). Selecting any other option prevents adjustment. Once I entered the PCE menu, I found the layout a bit different than what I am accustomed to. I quickly developed a love/hate relationship with this system. To the positive, it is extremely precise with very fine adjustments. As you’ll see in the Benchmark section, I was able to achieve perfect hue, saturation and luminance for all six colors. To the negative, it is rather tedious to use. The hue, saturation and level (luminance) controls are in their own menus, each of which contains the six colors. Whoever designed this system failed to account for the fact that these settings interact. It took me about 5,000 button presses to dial everything in as I went back and forth between the menus to adjust each color. Another obstacle - the starting point is based on the projector’s native gamut which is huge. I had to move the sliders quite far just to get in the ballpark of Rec 709. It would be far easier to select one of the gamut presets and use that as the baseline. Then adjustments would be much smaller. Still, the end result was more than worth the effort.
Hot Tub Time Machine is loaded with saturated, almost glowing colors that portray the Eighties in all their stylistic glory. While the look sometimes borders on cartoonish, the detail I saw on the Q750i was simply amazing. I have watched many DLPs, including other Runco models, and the Q has a level of sharpness I’ve only seen matched by the Runco LS-5 and the Samsung SP-A900B. Detail was literally eye-popping. Even though I had it set to a peak output of 14.5fL, the excellent color transients and contrast made for an extremely vivid picture. Dark scenes were not the blackest I’ve seen though shadow detail was excellent. I tried the different ConstantContrast settings throughout the movie. Blacks were deeper with the control on Low. I didn’t see any improvement on Medium or High. I also saw no color shift or obvious change in gamma. Overall, I’d say the effect was subtle. I left it on for the remainder of my viewing. SatCo did cause an obvious change in color so I left it off. Adaptive Contrast deepened black levels further and increased peak output but at the expense of crushed detail. I also left this control off.
I chose Crimson Tide for two reasons, dark scene content and its natural color palette. Movies that take place inside submarines are loaded with tough-to-render shadow detail and objects that are often illuminated just by green or red panel lighting. A display not only has to deliver that shadow detail, it must do it in the presence of bright highlights and without visible noise or dithering. The Runco excelled on all counts with the Constant Contrast control on the Low setting. Even though this setting is a dynamic one, I never saw any variation in image brightness. Contrast was obviously greater but the effects of the control were invisible. The image was completely noise-free. Even when I looked at the picture from a few inches away, there was no sign of dithering. Crimson Tide’s natural color was also excellent. With accuracy this fine, you know you’re seeing the director’s intent at all times.
Alice in Wonderland is classic Tim Burton with monochromatic scenery punctuated by brightly colored objects or characters. Rendering of fine detail is what’s required here and the Q barely broke a sweat. Imagery like this looks flat on many displays but not the Q. The absence of lush colored backgrounds merely served to make the picture even more three-dimensional as elements like the Mad Hatter’s bright red hair or Alice’s deep blue dress popped out of the screen. I did not see this movie in its 3D presentation but in this case there was no need. Runco delivered all the 3D I could wish for.
None of the previous Blu-ray releases of NBC’s Heroes have been overly impressive in appearance and Season 4 is no exception. Grain is present in many scenes and becomes a distraction as the light level drops. Color is also uneven with casts that range from blue to magenta. Still, the sharpness is excellent especially in facial textures. There’s a little added edge enhancement but the Q750i managed to keep that from becoming an issue. The Blu-rays are an improvement over the hi-def broadcast and thanks to Runco, they look decent on the big screen.
The Illusionist is shot in a period style to fit its timeframe of turn-of-the-century Vienna. The entire movie is awash in golden hues and vintage textures. This kind of color interpretation makes it very hard to preserve detail in the image. Though it still looked flat to me, shadow and highlight detail were both preserved well by the Q750i. Faces, while still looking highly filtered, did show a relatively natural look. Another artifact I see frequently in films like this is moiré. When the color palette becomes monochromatic, fine gradations are tough for a digital display to render. The Runco’s excellent video processing handled this well always showing smooth unblemished transitions from light to dark.
Transformers Revenge of the Fallen is a feast both visually and sonically. It’s better used as an audio demo thanks to many thundering low-frequency effects but the picture looks pretty good too. The vast majority of the action takes place in bright desert sunlight. Highlights were never overblown and color while very saturated never lost detail. The CGI-rendered robots were totally believable with every scratch, paint chip and dent perfectly visible. The scene where Megan Fox lays stretched out on a motorcycle is about as 3D as it gets without wearing funky glasses and spending a fortune on new electronics.
Next I chose BBC’s Planet Earth with its lush natural color and super high-quality HD photography. There are few nature films that look this good from any studio. Motion processing is especially important here as the BBC camera crews have created the smoothest pans I’ve ever seen. If there’s even the slightest hitch in a display’s cadence, you’ll see it. The Q never faltered as I seemed to float over herds of antelope or fly through the rain forest canopy with spider monkeys and exotic birds. In the episode Shallow Seas I was again looking for moiré in the blue skies or vast expanses of ocean on the screen but found none. If ever there was a reason to buy an HD display, Planet Earth or the more recent Life is that reason.
As I’ve already stated, the native color gamut of the Q750i is very large. Ordinarily this would have little value since using the entire gamut would result in grossly oversaturated color. However Runco has included an option that lets you use the full gamut and still have decent accuracy. The option is called Runco Smart Color (RSC) and it’s accessed in the PCE menu. All you have to do is select the PCE gamut then enter the PCE sub-menu and turn on RSC. The net effect is flesh tones and other familiar colors are rendered correctly despite the pumped up saturation levels. When I read about this feature in the owner’s manual I was dubious but I certainly wanted to see for myself. Well, I was quite surprised. I set up two memories, one with Rec 709 colors and one with the native gamut and RSC so I could switch back and forth with one button press. The native gamut was very saturated and brilliant; far more than I’m used to; but flesh tones looked natural. Without RSC I would describe the native gamut as unusable for Blu-ray or DVD content but with RSC it’s quite watchable. If you want to have some room light present, this is a great way to preserve the picture. Combined with a screen like the SI Black Diamond 2, you would have a killer setup for front projection with low ambient light.
To test the native gamut setup with actual content, I watched clips from Seabiscuit (my favorite example of natural color) and Pixar’s Up. Seabiscuit looked great with really bright vivid color and excellent flesh tones. I was able to watch the clips with my lights on low, no problem. I saw no serious clipping of detail or other artifacts. Up, as you can imagine, looked even more cartoon-like, but in a good way. The only thing I noticed was occasional crushing of the brightest whites. Russell’s face for example glowed a little more than I’ve seen before. The balloons carrying Carl’s house though looked amazing. There are hundreds of different shades in the bunch and each one popped out beautifully.
On The Bench
Equipment used: EyeOne Pro spectrophotometer, CalMAN Professional 3.7 analysis software, Accupel HDG-3000 signal generator, Spears & Munsil Benchmark Blu-ray disc.
All measurements were taken off the screen (Carada Brilliant White, gain 1.4) from the seating position (10 feet back). Video processing tests were performed using an Oppo BDP-83 connected directly to the projector and set to Source Direct mode.
This is the Rec 709 preset with all other settings at factory defaults. Color error is minimal and luminances are almost perfect. This is excellent out-of-the-box performance.
Here is the Q’s native color gamut. Luminances are fine but the color points are quite far outside the Rec 709 gamut. Since Blu-ray and DVD content is mastered to either the Rec 601 or 709 standard, using the native gamut would result in extremely over-saturated color. Of course you can use the Runco Smart Color option to tame the flesh tones if you wish.
Out-of-the-box grayscale tracking is ruler flat but about 600K too warm at the 6500K preset. Gamma tracking is also very flat at the 2.2 preset.
After using the Personal Color Equalizer to calibrate the native gamut to Rec 709, I achieved the following result. Color error is under 1 Delta E and luminances are all within .03 fL of the target. You’re looking at perfection here folks.
Post-calibration grayscale was equally superb with all errors under 1 Delta E and near-perfect gamma tracking.
Video processing performance was excellent but not quite the very best I’ve observed. As usual, I used the Spears & Munsil disc with my Oppo BDP-83 set to source direct. Although the Q750i passed the tough 2:2 test, it failed on 2:3:3:2 and 2:2:2:4. It’s picking nits I realize but I only note it because the Runco LS-5 I tested a few months ago sailed through these clips. Bad edits were handled properly with instant lock-on. Edge-adaptive tests earned a passing score as well with just the barest hint of line twitter on the hockey rink’s plastic shields and the yellow trim on the ship’s hull. The ropes on both the bridge and ship clips looked fantastic. Scaling performance was excellent on all 480i clips. You won’t need a stellar disc player with this projector though I suspect most owners will have one anyway.
Contrast performance was on par with other DLP projectors I’ve tested recently. At Runco’s recommendation, I performed the calibration with ConstantContrast off. At the default contrast setting of 100, peak white measured 23.5fL. This is pretty close to Runco’s stated spec of 29fL. I used all the available vertical lens shift which accounts for the slightly reduced output. With contrast lowered to 20 and brightness set to 103 (default is 100), the measured minimum black level was .007fL and peak white was 14.5fL for a calibrated contrast ratio of 2071:1. With Constant Contrast on Low, the black level was immeasurable and peak white rose to 16.5fL. With Adaptive Contrast turned on, peak output rose to 21.5fL and black levels were again immeasurable. To the eye it didn’t appear quite as dark as the best LCoS projectors but it was awfully close. In normal viewing, the perceived image depth is excellent thanks to the Q750i’s excellent intra-image contrast.
Lens quality was among the best I’ve seen with no chromatic aberration or artifacts observed. Field uniformity was perfect with no observed change in light output or color from edge to edge.
Often reviews about the newest technologies end with phrases like “shows great promise” or “maybe in a generation or two…” Not so with the Runco Q750i. This projector is a standard-bearer right out of the gate. Its solid build quality speaks to the seriousness of its intent. This is not merely the first try for an LED projector. There is no reason not to consider this real competition for any bulb-based model. Light output is strong with plenty of lumens for a medium-sized theater. Performance and color accuracy is at reference level. With the Q you can have a no-compromise display with color stability and no bulb changes for the life of the product. Plus if you see rainbows with single-chip DLP, you won’t have to incur the considerable expense of a three-chip model since the Q has no color wheel. My take – the next great revolution in projector technology has arrived in the form of the LED. Perhaps bulbs will go the way of the CRT thanks to manufacturers like Runco. The Q750i earns my highest recommendation.