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Discussion Starter · #1 ·
Apple TV doesn't show below black or above white. I calibrated my samsung plasma's blu-ray input using the avs DVD-r I burned and the YouTube avs clips on my chromecast input. Both devices show below black and above white. The settings where the same between them. Color and tint were also the same. Enter the Apple TV... I had to bump color up a couple notches compared to blu ray and chromecast. What patterns can I use for black and white level, seeing how it crushes both past "reference" points? Thanks!!!
 

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Discussion Starter · #3 ·

Quote:
Originally Posted by DrFaxe  /t/1525278/how-to-calibrate-when-source-doesnt-show-black-or-white#post_24555066


Hello,


the AVSHD709 disc features black and white clipping pattern. You can download here:

http://www.avsforum.com/t/948496/avs-hd-709-blu-ray-mp4-calibration

I calibrated my display with that disc on my blu ray player input. The Apple TV has a different video output. "Color" needs a bump up as compared to the blu ray player and the chromecast (displaying avs DVD clips from YouTube). Looks like spears n munsil disc has a pattern for displays that cut off blacks at reference levels (2% & 4% above-black bars). Which pattern on avs disc has a pattern for calibrating sources that do not pass below black? Thanks
 

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Discussion Starter · #5 ·
I can't see 16 because the Apple TV doesn't show "below black". 17 and everything below it is not there.

99% of what I watch is streamed over Apple TV. I need to Apple TV and the tv to be calibrated to one another.

Btw, just found the thx calibration app for iPhone that can be mirrored thru the Apple TV. I'll play with it tonite.
Quote:
Originally Posted by DrFaxe  /t/1525278/how-to-calibrate-when-source-doesnt-show-black-or-white#post_24555704


chapter "basic settings" --> "black clipping". it shows black from level 2 to 25 (16 is video black).
 

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what is the lowest level You see flashing, 18?

Your brigthness is set correct if everything below 16 is black and 17 is barely visible.

You need to adjust the brightness setting on Your TV to make 17 visible and everything below to be black, than You are done.
 

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When BTB/WTW is clipped, bar 16/235 will never be visible, they will blend to the background of their respective test patterns.


For Brightness, just set it so bar 16/the background is as dark as possible and bar 17 is barely visible. Start low so 17 completely disappears, then slowly increase it until it's just barely visible. You could also probably just display a black field, start with a low setting, then slowly increase until your black levels noticeably increase, then go back a click.


For Contrast, since >235/WTW is being clipped anyway, just make sure there's no clipping or discoloration on bar 235 and below. If there's not, no matter how high you set the Contrast, set it so you don't experience eye fatigue.
 

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Discussion Starter · #9 ·
Thanks! What % of black r bars 17 and 18?

The thx app I played with using mirroring thru Apple TV shows a drop shadow behind the logo. I thought those were below black. Weird!
 

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Are you really talking about calibration or are you just wondering what Brightness, Contrast, Color and Tint settings to use? Calibration means you are using a meter and software to actually MEASURE the TV and set it up as close as you can get it to home video standards. If you are just using a test/setup disc to get the basic settings right, that's not calibration... that's setting the stage for calibration... like getting the right amount of air in your tires before you begin to calibrate your suspension for better handling using tools and test equipment.


So why do you think the fact that Apple TV displays only 16-235 means you have to do anything different about calibration or settings?


Brightness control - reduce it until step 18 disappears, then increase it 1 click so that you can see 18 again. This is verly likely to be the same step you use for every other source or at WORST 1 click higher.


Contrast control - sets white level. If you set 100% white to produce somewhere around 35 fL you will get 35 fL for 100% white on the Apple TV box. If you don't have a meter and calibration software


Just use the same Brightness and Contrast settings you use for other soures... 98% of the time, those will be within 1 or 2 clicks of a source that's not quite right. Fine tune if you wish.


NO existing test/setup disc can tell you what the RIGHT Contrast setting is. All the disc can tell you is the HIGHEST Contrast setting you can use. And the HIGHEST Contrast setting you can use (if a display or device does not clip white), is rarely the RIGHT Contrast setting. There is simply no way for your eyeballs to tell you when you are seeing 35 fL: for 100% white in a dark room. The Highest usable Contrast setting (if you don't want to clip white) could be producing 50 or 60 or 70 or even more fL than that. All of those are much too bright for a dark room. Lacking a meter, the only way you can set Contrast is to watch content for 2 hours or so in a dark room, then note whether you feel any eyestrain. If you do, back off on Contrast a bit depending on how noticeable the eyestrain is. The view another 2 hours of content and take note again of whether you notice the feeling of eyestrain or not. At some point, when Contrast is in the right range, when you do that, there will be little or no noticeable eyestrain. So if the disc tells you you can use a Contrast setting as high as 85, you might find that the RIGHT Contrast setting is really 60 using the eyestrain test.


If you don't have a dark test pattern with digital steps from 0-25 or so, just use whatever PLUGE pattern you have. The lighter gray bar that is never supposed to disappear (it is flashing on some discs and not flashing on others). make it darker until it disappears, then increase the Brightness control about 2 clicks so that it comes back. That will very likely be within 1 or 2 clicks of the Brightness setting you use with other sources.


I think you're making this thing more difficult than it really is. It's not really much of an issue if below black is clipped or if above white is clipped. There is no image detail above 100% white. All you see up there is what is called "spectral highlights". These are reflections off of chrome, or of the sun off of water, or of light reflecting or refracting on a crystal of a chandelier... things like that. You really don't lose any real image detail if white is clipped above 100% and again, the disc you are using is not telling you the right Contrast setting to user, it is only telling you the highest setting you can use before white is clipped above 100% --- and that highest setting will never be the right setting unless you have a very very dim TV. In the age of CRT, the highest usable Contrast setting was often the BEST Contrast setting because many CRT displays just weren't all that bright before you would get blooming and other artifacts that would detract from image quality. But CRT days are way behind us for most people and modern digital video displays, even plasma, are often not used at the highest Contrast setting when you set them up with a meter.
 

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Quote:
Originally Posted by Andrei_VVB  /t/1525278/how-to-calibrate-when-source-doesnt-show-black-or-white#post_24558996


Doug...shouldn't be the 17 bar seen when adjusting brightness?
I was wondering the same thing. Typo perhaps?
 

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Quote:
Originally Posted by PlasmaPZ80U  /t/1525278/how-to-calibrate-when-source-doesnt-show-black-or-white#post_24560013


I was wondering the same thing. Typo perhaps?

I think Doug said 18 because the OP said that on his setup, "17 and everything below it is not there". I imagine that when you're only using a calibration disc in cases like that, you then make 18 barely visible so you can minimize how much of the low end is being clipped, much like in a normal scenario when you make 17 barely visible.
 

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AVS black clipping pattern if everything is in check a BTB and WTW is being displayed like from your best source say a Blu-ray player. 16 invisible and 17 barely visible, even if you have to get right up on your screen with your nose to see this.
 

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Right, I mentioned 18 because the OP said he never sees 17.


Yes, 17 should be visible if you can make it visible. But there are a surprising number of displays that raise the black level a bit when you get Brightness set to show 17... 16 may look black, but black itself is a little brighter. Go one click darker and you lose step 17 but the black level is detectably darker. If that is the case, I would opt for the better black level by sacrificing the visibility of 17.


This is a tradeoff I would make for viewing content at home on my own system. If I was editing video for movies or TV using a reference monitor and had the same issue, I'd probably make a different decision... like show step 17 even if the black level takes a hit. So the context of the decision is important.
 
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