Originally Posted by Drew Neilson
I'm shopping around for a new 3D Blu-ray player and although I've learned that in general there isn't much variation in the picture quality of Blu-ray players when they are playing Blu-ray discs, I don't understand why there is any variation AT ALL when an HDMI connection is used, since there is no digital-to-analog conversion happening; they simply take the digital data that exists on the Blu-ray disc, and send it to the AVR or TV via HDMI, right?
I'm surprised Chris H. hasn't chimed in on this. Here are two articles from Secrets on the above subject though (since Bill's original answer went kaput, and the link in this thread
is now broken)...
The Secrets Blu-ray Player HDMI Benchmark - Part I
The first page in the above article explains why it is not possible for any
player (including Oppos) to transfer video directly from a Blu-ray disc to a display as originally encoded. It has to do with differences in color spaces and sub-sampling supported by the two devices. The best you can hope for is accurate YCbCr 4:2:0 to 4:2:2, 4:4:4, or RGB conversion.
And this quote from a SpectraCal rep explains why accurate color from a player is important if you want your display correctly adjusted...
The Secrets Blu-ray Player HDMI Benchmark - Part 2
Originally Posted by The Secrets Blu-ray Player HDMI Benchmark - Part I
"if you rely on your optical player (Blu-ray or DVD) as your primary source and you use it to generate reference test patterns from a pattern disc to calibrate your display(s), there is no guarantee you will end up seeing the content as it was originally intended. This is due to the possibility that you will have improper source decoding and perceivable deltaE in output levels. If this occurs, your entire video chain including the display will not be calibrated properly and the quality of the original content will be lost."
The follow-up article demonstrates how a calibration can go wrong due to incorrect color output in your source device (e.g. BD player). Very interesting read (if you're a HT geek).
The last time I went shopping for a BD player 1-2 years ago, just about all the players I tested were outputting incorrect colors in their RGB modes. Sony subsequently fixed the issue on my S390 (and their other players, I assume) in a firmware update.
Accurate RGB output was important to me at the time, because my older 2002 Sony CRT would not accept YCbCr signals on it's DVI-HDCP input. So RGB was the only way to send 1080i to the TV from a BD player.
I did not have an accurate way of testing the S390's YCbCr output at the time, but have since confirmed that it's correct using the Red Only, Green Only and Blue Only modes on a couple Samsung plasma displays.
The reasons why there are errors/inaccuracies in the color output of video players, receivers, etc. are myriad btw, and not just related to color space conversion. If you want the real answer to that question, you'd have to ask each individual mfr... though I doubt most would give a coherent answer.