Gamma set @ 2.22 - Should I re-adjust brightness after? - AVS Forum
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post #1 of 7 Old 07-03-2012, 11:56 AM - Thread Starter
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After using the latest HCFR ive set my gamma at 2.22 and have a nice horizontal line all the way from 10 to 90 IRE', however on checking the brightness using the AVS HD brightness pattern it is indicating i should raise brightness as only bars 18 and above are flashing, and not 17 as recommended.
The million dollar question is do i adjust brightness?

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post #2 of 7 Old 07-03-2012, 03:30 PM
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Quote:
Originally Posted by ndaa75 View Post

After using the latest HCFR ive set my gamma at 2.22 and have a nice horizontal line all the way from 10 to 90 IRE', however on checking the brightness using the AVS HD brightness pattern it is indicating i should raise brightness as only bars 18 and above are flashing, and not 17 as recommended.
The million dollar question is do i adjust brightness?

Calibrating is an iterative process. Keep adjusting and readjusting until you get all parameters as close to standard as you can.

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post #3 of 7 Old 07-03-2012, 04:31 PM
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The difference between clipping at 16 or 17 is not very significant, so I wouldn't worry much about this.

Another thing to note is that to get the correct black level you should be turning it up until you see 16 against the background, then down till you can't see 16. 17 should then be handled by a multi-point gamma adjustment.

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post #4 of 7 Old 07-04-2012, 09:33 AM
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The other issue that comes up is that the Brightness control might show step 16 against black at say +1 but set it to 0 and you lose step 17 but can see 18 or 19. It would be worse to leave the control at +1 to show step 17 because the black level, step 16 would be raised too high and the display would lose contrast ratio because of the black level not being as dark as it should be.

Always get black as black as it can be... make step 16 just barely appear, then adjust Brightness 1 step darker so step 16 disappears into the black background. If you lose step 17 or even 18... that may be the best your TV can do. There's a fairly good chance that there's not going to be an adjustment in the panel or projector that will make step 17 or 18 visible without messing something else up. In the end... it's pretty inconsequential if step 17 isn't quite visible. Better that, than to have the black level too high.

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post #5 of 7 Old 07-05-2012, 11:01 AM
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Hello, try using the near black test pattern for HCFR with the AVS HD709 disk. Tom Huffman has a method where you put up a 0 IRE full field test pattern and crank your brightness high then slowly back down till you no longer see a change in the brightness of the screen. Sit close to the set very close like a couple of inches away so you can see better when you hit the correct point. The red green and blue pixels will all be turned off indicating the blackest the set can get, if you lower it any further then the screen won't actually get darker but you might end up crushing detail near black. Good luck smile.gif
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post #6 of 7 Old 07-05-2012, 04:14 PM
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Quote:
Originally Posted by hungro View Post

Hello, try using the near black test pattern for HCFR with the AVS HD709 disk. Tom Huffman has a method where you put up a 0 IRE full field test pattern and crank your brightness high then slowly back down till you no longer see a change in the brightness of the screen. Sit close to the set very close like a couple of inches away so you can see better when you hit the correct point. The red green and blue pixels will all be turned off indicating the blackest the set can get, if you lower it any further then the screen won't actually get darker but you might end up crushing detail near black. Good luck smile.gif

I think the black clipping pattern on the AVS disc is both the easiest and most precise/accurate way to set brightness. Methods involving a meter are usually less reliable and at best can help you decide between two settings that are only one click apart (like 55 vs. 54).

Also, keep in mind that ambient light (especially any light that hits the screen directly) can affect the brightness setting, especially when using a high precision pattern that shows various digital values in 1-pt increments like on the AVS pattern mentioned above.
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post #7 of 7 Old 07-07-2012, 02:07 PM
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I use the AVSHD709 black clipping pattern, but it usually ends up being the same as using the method hungro described.
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