- Written by Chris Heinonen
- Published on 08 July 2012
The BenQ W7000 Projector On The Bench
Before calibrating the BenQ W7000 I compared its performance with a high-resolution mutiburst pattern at 4:2:2, 4:4:4 and RGB colorspaces. When set to Auto mode for HDMI, it seemed to both clip WTW and BTB data, and with RGB signals it didn't process the highest resolution ones correctly. If I set the input mode to PC, then WTW and BTB were passed, and the RGB Multiburst looked better than either YCbCr version for color information. Unfortunately when I then sent YCbCr data the black level would adjust, and so I set all of my devices to be RGB output. Since auto-detection of RGB and YCbCr didn't seem to work correctly over HDMI, I'd recommend setting the BenQ to one mode and your devices to that as well. WTW and BTB are never passed on the BenQ when using YCbCr either, which clips your headroom.
Calibration was performed with an AccuPel DVG-5000 signal generator, an i1Pro and i1DisplayPro meters, and ChromaPure software.
Pre-calibration, while aiming for a gamma of 2.22, the BenQ gets close to that but the grayscale is not very accurate at all with a heavy green push. When we look at the color data, we can see that the green luminance error is off the charts, helping to cause this shift in the grayscale. This is pretty routine performance for a projector out of the box that doesn't have THX certification or another preset calibration mode.
Thankfully the BenQ W7000 is both ISFccc capable, and has full user controls for the CMS. The benefit of the ISF mode over the user mode is that the controls are locked away, so no one in the family can accidentally erase or adjust a setting to remove the time spent fixing it. Since access those modes requires the ISF password and knowledge of how the DLP CCA modes work, I will focus on user mode. Using ISF mode gets you results that are practically identical I found, in case you do have a calibrator come in.
Using the Warm color mode and 2.2 gamma setting, I was able to get almost every point on the grayscale to a dE1994 under 1 with only the darkest shades at 10% and 20% coming in above 1 but still below 3, and the gamma to be almost spot on perfect. With only a 2-point white balance control, this is a very nice result, and will give you a totally neutral grayscale in use. I should also mention that this performance can only be obtained if you set the contrast to not clip white until after level 255. Many people clip in the range of 235-240 since content shouldn't have information above that level, and it gets you higher light output that way. Since the BenQ has plenty of light to spare, you should let this range extend all the way out as otherwise I found a gamma bump and color shift at 90%.
Adjusting the CMS was more of a challenge. With how the Hue and Saturation controls interact, as soon as you adjusted one to be nearly perfect, the other would adjust itself off again and you no longer had a perfect color point. Because of this I tried to get the colors as close as possible, with errors +/- 2% in Hue, Saturation, and Lightness. In the end some colors did exceed those 2% limits due to the issues with the CMS, but the overall dE1994 for the colors ranged from 0.7-1.7 which was very good. Properly calibrated, you a near reference image with the BenQ W7000 projector.
Looking at various saturations and luminance values, you can see compared to the starting values that they were much improved overall. Cyan is a little bit off, but everything else is very good. When using RGB the Color and Tint controls are locked off, so you can't use those to make additional adjustments. The CMS of the BenQ works very well overall, brining the color accuracy far more in line than it was at the beginning.
After talking to BenQ and being informed that Dynamic mode runs the color wheel at 6x instead of 4x, I tried using this mode for a calibration. You can get a pretty accurate image out of it that is good until 80% and then starts to lose red at the top end, but put out a remarkable 45 ftL of light on my screen. In order to get that grayscale to be totally linear, I had to reduce contrast to the point that the peak white level was 22 ftL, but I now had an image that was very accurate and using the faster color wheel for fewer rainbows. It wasn't quite as accurate as User mode, but if you see rainbows the lower light output and slight loss in color fidelity would certainly be worth it.
One issue I did have was getting the sharpness control set correctly on the BenQ. A setting of 0 was fuzzy, and above 5 there was edge enhancement setting in. Going to 5 was the best choice for me, but at that same level I noticed some color fringing on the screen as well and the finest detail in wedge patterns were still showing some edge enhancement artifacts. The lens or the sharpness control could introduce this, but there was certainly a purplish tint at certain points on the Spears and Munsil pattern. It seems there is no setting in the BenQ that results in exact 1:1 processing of the image with no enhancement at all, but I found 5 to be the best setting overall with the fewest artifacts.
On my 96", Screen Innovations 1.3 gain Solar HD screen I measured a peak light output of 29.42 fL in low lamp mode, and a pure black level of 0.031 fL. This would give me a lumens estimate of 600 lumens and approximate contrast of 935:1. If I enabled Dynamic Black the black level dropped to 0.01, raising the contrast ration to almost 3,000:1. Turning on high lamp mode the white output raised to 36.8 fL, for 770 lumens, with all values out to 255 still visible. There is plenty of light to spare here.
Measuring the contrast ratio straight from the gave me a reading of 890:1 with Dynamic Black off, and 2900:1 with Dynamic Black on which is almost identical to off the screen. I always focus on the number without the iris, as it is more applicable to actual content. These numbers are pretty low for a DLP and likely due to the choice of the DarkChip 2, but the very bright highlights in scenes helps make the blacks appear darker in content.
In the end you can get a well calibrated image from the BenQ, but you will have to be very careful in your choice of colorspaces, where to clip white, and striking a balance between Hue and Saturation to get the CMS points dialed in correctly. It's a bit finicky but it can get there with some work.