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Samsung HDMI black level setting - explanation required

BigBlue007

Novice Member
WARNING: Lots of text, and I'm not even sure whether I'm able to explain clearly enough what I'm trying to say. :)


I am new to the world of Samsung TVs (F8000). It's the first TV I own that allows a manual selection of the HDMI colorspace. Since I like to understand things, I tried to figure out what option stands for what, but all I found is confusion so far.

According to my searches, most folks say that the "Normal" setting is for Video-Levels (16-235), while "Low" is for PC-Levels (0-255). Some other folks say it's the other way around.

I did some research using some of my external HDMI sources (Dreambox STB, Apple TV, PS3). The Dreambox uses Video-Levels (16-235). The Apple-TV allows to choose between YCbCr (which is always 16-235), RGB with limited 16-235 range, and RGB with full 0-255 range. The same is true for the PS3, where you can choose between YCbCr and RGB for video playback, and for RGB you can choose between limited and full range RGB.

Now here's what I found so far: When I set Apple TV or PS3 to YCbCr, the Samsung's HDMI blacklevel option defaults to "Normal", and it is greyed-out. Once I set Apple TV or PS3 to RGB output, the Samsung defaults to "Low", but now the option can be toggled between "Low" and "Normal".

Based on this finding, I was under the impression that "Normal" must be 16-235 (because any source device that outputs YCbCr uses the 16-235 range), and "Low" must be 0-255.

BUT: When using RGB output, both PS3 and Apple TV allow to change whether to use full or limited range. Using the PS3 I found out the following: When I configure the PS3 to "Limited" RGB range, start a game and toggle the Samsung option between "Low" and "Normal", all blacks are black with the "Low" setting, but gets grey with the "Normal" setting. This now indicates that unlike found out above, "Low" is limited range and "Normal" is full range, because if the PS3 is set to Limited, it outputs black as 16. Now if blacks are black on the Samsung with the "Low" setting, but gets grey with the "Normal" setting, it clearly means that "Low" is limited range and "Normal" is full range, because with "Normal" the Samsung expects black to be 0, and therefore blacks from the PS3, which are 16 if the PS3 is set to limited range, are not black, but grey from the Samsung's point of view.

So here's what I didn't understood: In YCbCr mode, the Samsung switches to "Normal" and doesn't allow to change this option. Since YCbCr is always limited range, "Normal" obviously stands for limited range. However, if players use RGB mode, the above test clearly shows that "Normal" is now full range, while "Low" is limited range.

I had this discussion in a german forum, and one guy came to the following, IMHO quite interesting and sense-making conclusion: "Normal" and "Low" are not used by Samsung as fixed synonyms for full range and limited range. Instead, their "Normal" stands for the range that is "normally" used in either YCbCr or RGB mode. And for YCbCr, the "normal" case (or the ONLY case for that matter) is limited range, and for RGB, the "normal" case is full range. Since there is no "YCbCr full range", you cannot change the "Normal" setting in YCbCr mode, because there is no other case than this "normal" case. In RGB mode however, you can mostly choose between the 2 ranges and are therefore allowed to toggle the option, but since full range is the "normal" case for RGB, the "Normal" setting now stands for full range.

I can perfectly live with this explanation, but I'd still like to know whether all this make any sense to you guys. And if not, why?

By the way, there is one thing left to explain which doesn't fit to that explanation: When using the internal tuners, the option defaults to "Low" and is greyed-out. This doesn't make any sense, because TV stations are alway YCbCr. So you would expect that if the setting defaults to "Normal" and is greyed-out when using an external source that is set to YCbCr mode, it should also default to "Normal" (and being greyed-out) when the internal tuners are used.
 

sfumato

Standard Member
So did you ever figure this out? Heres what Samsung says,

HDMI Black Level:

The HDMI Black Level option will compensate for the black level range of an HDMI input. When this option is set it can expand the black level range to 0-255 from a YCrCb color source. When an HDMI device that supports an RGB color range and already use the 0-255 HDMI black level range is connected, the HDMI Black Level option will be grayed out. There are two options for setting HDMI Black Level;

  • Low: Sets the HDMI Black Level enhancement for deeper black level range.
  • Normal: Sets the HDMI Black Level enhancement for what the device is sending.
here is the link,
Operation: How To Change The Picture Settings On Your LED TV : | Samsung

So I guess it depends on how I have my Xbox one set up? I have it at TV, the other option is PC. All I know is PC at normal looks terrible. Set at TV (limited?) with HDMI of Low looks good. But "my" logic tells me that one would want to have it set at "what the device is sending"...only that looks like crap.

Just wondering if I should use the same for blue ray.
 

noiseboy72

Distinguished Member
It only matters when viewing movies and other program material. In order to allow for some creative control by directors and film colorists, the very lowest level of black should not be seen on a properly set up TV. The bottom 16 steps of black therefore, should not be displayed. With the level too high, you sometimes see unwanted detail in the frame - like black mattes and digital effects covering up bits of equipment caught in frame, that sort of thing.

On a badly set up TV, the black level might appear too high, with the deepest black more of a murky grey. Therefore, many people compensate by running the black from 0.

Does this make sense??

For games and even desktop, run Full black, but for movies, set the level to normal, but ensure the TV is set up correctly - with the lowest 16 shades of black invisible. To do this, you need a setup disc - or the AVS Forums files they freely distribute, which allow you to set up the brightness correctly.
 

sfumato

Standard Member
Yes makes sense. I think I need to have a THX Certified Video Professional come over to my house and set my tv, xbox one, and its blu ray player up. The confusion comes with how to set the xbox up, it has two options TV and PC. From what you said when playing games I should use PC, which is full, and set my HDMI to normal.
Then when watching blu ray on xbox I should switch it to TV, and my HDMI level on TV to low?
I have to say that when I did have it on PC and Normal for gaming I could not get the calibration brightness pattern to show the image (eye that you are supposed to be able to see).

thanks for your help.
 
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