"High Definition Benchmark" BD Edition by Stacey Spears and Don Munsil - Page 41

Thank you so much for your quick replay!

Me too, I read that VT50 has a best performance with 4:4:4. But, in this case, I have to set 4:4:4 on Radiance output configuration?
If Radiance is configured in 4:4:4 to VT50, It's ok set the sources in input to Radiance in 4:2:2? In general my sources are in 4:4:4 and I can't change this parameter (only on my bdp I can)...
And about dither? It's ok if I set 10 bit on radiance? Is this setting the best to VT50?
Thank you so much for your explanations and for your help
Vincenzo

If you want to know of 4:4:4 is better than 4:2:2 into the VT50, then bypass the Lumagen and test with the player plugged in directly to confirm. Once you have done that you will know what to set the output too. At that is done, you can test input into the Lumagen.

For dither, try looking at the various ramps on the disc and see if you see a difference between them with and without dither. You might also pick some gradients in movies such as sky or underwater and look at this with and without dither.

Thank you so much Stacey!

I'll try the process you suggested and, finally, I hope to have the best configuration for a good calibration

Otherwise, I think my pipeline it will be (about dither I have to test):

• BDP -->4:2:2:-->Radiance-->4:4:4-->VT50
• Other sources -->4:4:4-->Radiance-->4:4:4-->VT50

A question. In an italian forum I read that films are in 4:2:0 and the forumer suggest 3 way to set the video pipeline:

He suggest using the number 2 or 3 (better 2) because they have fewer conversions (the Y'CbCr 4:2:2 will be always converted in Y'CbCr 4:4:4 and finally in R'G'B' that is the last conversion). It's true? What do you think about that?

The Radiance processes internally in 422. If memory serves, at 12 bit. It will output 422 12 bit if Styles> HDMI Format is set to 422 and dither is set to off. 444 and RGB output is 8 bit only.

Dsinger thank you for the information!

Now, otherwise, I'm very doubtful. Panasonic VT50 can accept 12 bit input? As I said, the best input for VT50 seems to be 4:4:4...so If 4:4:4 is 8 bit, also VT50 is 8 bit only?

I don't know about the VT 50 but the 600u I bought in Fall 2006 would accept 422 12 bit from the Radiance. My advice is to try all the color spaces and bit rates using the S&M multi burst tests as well as others and see if you can see a difference.

Dsinger thank you so much for all!
Now I have to test and configurate all but I have a little bite more knowledge

For the moment....goodbye
Vincenzo

It's really not that simple. There are situations where #1 will work better. You just have to test all combinations and find out. In a perfect world, they would all be essentially identical, but that's not always reality.

The biggest problem with feeding Y'CbCr 4:4:4 or R'G'B' into a display is that many of them convert that signal back to Y'CbCr 4:2:2 for video processing like picture controls (brightness, contrast, etc.) CMS, sharpening, non-linear "enhancement" features and so forth. So on those displays, you're wasting your time (and potentially degrading the image) doing a conversion beyond 4:2:2 in the player.

The only way you would know whether it's internally converting to Y'CbCr is by looking at the motherboard for off-the-shelf chips that are known to only handle 4:2:2, or by telltale signs in testing. One of which is that you get a better picture feeding it 4:2:2 than 4:4:4.

So our answer is "Test. Don't assume."