- Written by Chris Eberle
- Published on 16 September 2010
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.