Blacker than black (1 Viewer)

[George_W_K]

I am a little confused on this subject. I have played the various test patterns to calibrate my tv and I do not see the blacker than black bars they mention. Is this because my DVD player does not output the signal? Or my TV does not show this? I plan on upgrading all of my equipment when I finish my electrical apprenticeship in a year and a half and I don't know what to look for when it comes to the blacker than black. I don't even know what this means.

When I asked a sales guy at a AV store around here about whether or not it was the tv, DVD player, or a combination of both, his reply was pretty much unhelpful. He went over to a TV and turned it off. He said, "That's as black as that tv can produce. You're not going to get any darker." Thank God for this forum!

 

[Matthew Todd]

Someone else will probably be able to explain this better, but I'll try.

I believe the "blacker than black" comes from the fact that our NTSC system here in the US defines black as 7.5 IRE, rather than a 0 IRE. So anything lower than 7.5 but higher than 0 is going to be "blacker than black."

As you've said above, some players will not pass a "blacker than black" signal. That could be why you're not seeing it.

On Video Essentials (I can't remember Avia) they use (I think) 2 black bars where one is blacker than black when setting the brightness of the TV. If the brightness is too high (or is it too low?), I think the blacker than black bar disappears. It may be that the reason you can't see it is just because the brightness is set to high. If you've run the brightness all the way up and down and never saw it, it's probably because the DVD player doesn't pass the "blacker than black" signal.

In practical use, I don't know that it makes much difference whether the player will pass "blacker than black" or not, because the system (NTSC) is designed to put all the video information in the picture at 7.5 IRE and above.

"Blacker than black" is useful for calibrating, but other than that, I don't know that it's necessary.

Even if you're player doesn't pass "blacker than black" you should still be able to calibrate reasonably well. I don't remember what the method to that is right now, but hopefully someone else will chime in and provide the answer to you.

Matt