Projector Calibration Review Using X-Rite i1 Display Pro

X-Rite i1 Display Pro

Purchasing calibration tools to setup your home theater is popular today. The question you should have before investing in these tools is do they really improve my results. As a professional in the field with very high quality tools I can say the vast majority of video calibrations that are being done in home theaters are very poor. The results are also frequently worse than what could be achieved by not using the instrument and just selecting a good picture mode and some reasonable basic settings. The following is a comparison of the results from using an i1 Display Pro on a Sony VPL-VW500ES (foreign version of the VPL-VW600ES) versus professional tools optimized for the task by AccuCal.

Let’s first compare the calibration of the color white from dark levels to bright. The charts below show the difference in the results from using an i1 Display Pro to AccuCal proprietary tools which are referenced to a $24,000 spectrophotometer (PR-670). The white in this case was visually shifting from purple at very dark levels to bluish to near correct at the very brightest level using the i1 Display Pro. This was obvious when looking at images on the display. I find this type of error to be very common. Most tools people purchase are very poor near black and improve as the image gets brighter. Unfortunately, images are dominated by the dark regions and poor color performance there looks very odd. When you are calibrating a display the near black should look very dark charcoal gray when displaying white balance patterns.

DIY White Balance Versus Professional

Adjusting color gamut in general is very difficult to do in a way that actually improves image quality. Instrument accuracy suffers as the colors become more saturated and balancing primary and secondary color with flesh tones and the other memory colors is complex. Color accuracy can also vary as the image changes levels of illumination. The following chart shows the very poor results obtained with the i1 Display Pro versus AccuCal proprietary methods. The i1 resulted in colors that were generally not saturated enough by a wide margin. This caused the image to look washed out in color compared to what it should. I am not sure I have ever seen a Sony projector out of the box this bad. The tool in this case almost certainly made the image quality worse than selecting a good picture mode alone would have done.

DiY Color Gamut Versus Professional

Here is another persons observations you should consider as well. This is a quote from Scott Wilkinson of Home Theater Geeks Episode #129 (@16:50). He is talking with Derek Smith from SpectraCal who makes CalMan. Scott makes the following observation about his experience with calibrating his displays, “Why is it that CMS’s, color management systems, so often make the picture worse than if you did nothing at all…In many cases is just looks horrible.” They go on to discuss the reasons why and possible solutions, but I find Scott’s observations about CMS calibration to be true in the vast majority of systems I work on where someone has tried to set the CMS or any color setting based on an instrument. My conclusion is that most of the tools and techniques people are using are too flawed for the task.

I believe the best way to tell if your instrumentation is working well is if it is not telling you to change products that are already correct or very close like Sony BVM and PVM color grade OLED monitors which are made to be +-1%. When I work on these displays very small changes to white are all that is required when these products are relatively new to achieve a very accurate image. High quality video sources just look stunning on these displays because of their technology and accuracy. Here are several professionals observations about these monitors which have phenomenal overall performance. Note the comments about the beautiful colors. This is what a color accurate display can do.

The goal of calibration is to render beautiful images as close to these processional monitors as your display can reproduce. If your tools are pushing you further away what is the point.

If you are calibrating displays you should always compare the results with real images and not just test patterns and data from your tools to verify you really made things better. It is best to do this with two separate memories so you can easily toggle between the before and after. If you are having to get used to a calibrated image something is wrong. An accurate image is a very attractive thing and does not require getting used to. It can also be useful to do this in steps by verifying each major change as being something positive in nature as you proceed with the process you are using.