AVS Forum banner

Black Crushed After Calibration (see pictures)

5K views 11 replies 8 participants last post by  Doug Blackburn 
#1 ·

Hello,

 

I have bought a new TV : SONY KDL-50W685A and I have used a Spyder4 TVHD and HCFR Software and AVS HD Pattern to calibrate it.

This TV was really bluish before calibration but after calibration black are crushed !

 

I don't understand why... I need your help !

 

So here's the result :

 



 

As you can see on the right of the head's creature after calibration black are crushed...

 

My setting after calibration :

Picture Mode : Cinema 2

Backlight : 7

Contrast : 90

Brightness : 50

Colour: 50

Colour Temperature : Neutral

Hue : 0

 

Gamma : -1

 

Gain Red : -2

Gain Green : -10

Gain Blue : -26

Bias Red : +1

Bias Green : 0

Bias Blue : -3

 

Here's the result under HCFR after calibration :

 



 

As you can see the gamma is not correct on the left but I supposed it is due to the limitation of the Spyder4 TVHD...

 

So What do you think ? How I can have correct color with correct black ?

 

Thanks !!
 
See less See more
2
#4 ·
Hard to tell from the tiny pics, but it looks like you're using an older version of HCFR, and I think he's using power gamma.


Get the latest version of HCFR here: http://sourceforge.net/projects/hcfr/files/Windows/


I would try either BT.1886, display gamma with black level compensation, or power gamma with a lower reference gamma target. Also turn off auto-dimming for calibration if there's an option to, and turn it on afterwards (if you want).


edit: seems as if you already did use black level compensation. I would do it again but with auto-dimming off. Auto-dimming is probably causing your black level to measure 0, essentially giving you a pure power gamma. Again, you can turn it on after if you want.
 
#5 ·

Quote:
Originally Posted by rahzel  /t/1507111/black-crushed-after-calibration-see-pictures#post_24106665


Hard to tell from the tiny pics, but it looks like you're using an older version of HCFR, and I think he's using power gamma.


Get the latest version of HCFR here: http://sourceforge.net/projects/hcfr/files/Windows/


I would try either BT.1886, display gamma with black level compensation, or power gamma with a lower reference gamma target. Also turn off auto-dimming for calibration if there's an option to, and turn it on afterwards (if you want).


edit: seems as if you already did use black level compensation. I would do it again but with auto-dimming off. Auto-dimming is probably causing your black level to measure 0, essentially giving you a pure power gamma. Again, you can turn it on after if you want.
 

I use the last version of HCFR 3.1.0.4 ...

I don't have auto-dimming option in settings on my tv.
 
#6 ·

Quote:
Originally Posted by poulpii  /t/1507111/black-crushed-after-calibration-see-pictures#post_24106877


I use the last version of HCFR 3.1.0.4 ...
Yes, my mistake... I see that now. I posted just before I had to step out. I thought I saw tracking at 0% and newer versions of HCFR don't display 0% measurements for grayscale and gamma.


Also just realized that you only have a 2pt white balance so calibrating to bt.1886 isn't really possible.
Quote:
I don't have auto-dimming option in settings on my tv.
You sure? According to this it has frame dimming (which is kinda what I meant)
http://www.sony.co.uk/product/tv-126-50-lcd/kdl-50w685a


If possible, turn it off while calibrating.


Since you only have a 2pt white balance, if you want better shadow detail, try a lower gamma.
 
#7 ·
From the picture is looks like before your calibration , your gamma was too low, making shadows appear brighter then they should be. The after gamma might be a tad low in the lower stimulus of the gamma range effecting shadow detail but to me it doesn't look like it's crushing blacks. They just appear dimmer in the after calibration picture. All the detail still looks like it's there. Just my opinion though. I forget now if your gamma is higher at one stimulus level then it should be say 2.28 and not 2.22 is this dimmer or brighter? and I am guessing it's the opposite when it's lower then it should be.
 
#8 ·

Quote:
Originally Posted by poulpii  /t/1507111/black-crushed-after-calibration-see-pictures#post_24106877

Quote:
Originally Posted by rahzel  /t/1507111/black-crushed-after-calibration-see-pictures#post_24106665


Hard to tell from the tiny pics, but it looks like you're using an older version of HCFR, and I think he's using power gamma.



Get the latest version of HCFR here: http://sourceforge.net/projects/hcfr/files/Windows/



I would try either BT.1886, display gamma with black level compensation, or power gamma with a lower reference gamma target. Also turn off auto-dimming for calibration if there's an option to, and turn it on afterwards (if you want).



edit: seems as if you already did use black level compensation. I would do it again but with auto-dimming off. Auto-dimming is probably causing your black level to measure 0, essentially giving you a pure power gamma. Again, you can turn it on after if you want.

I use the last version of HCFR 3.1.0.4 ...

I don't have auto-dimming option in settings on my tv.

Hello, display a Brightness Pattern with Flashing Bars, do you see any problem there? black crushing etc.
 
#12 ·
Frankly, your Before picture looks like the Brightness control is 2 or 3 clicks too bright. Your After picture makes it look like the Brightness control is 1 click too dark. As Ted said, use a brightness evaluation pattern (PLUGE or digital levels 0-25 (a better pattern IMO)) to see if you have the black level set correctly or not.


Your After photo IS NOT showing a huge amount of black crush... if the control is off, it's not off by more than 1 or 2 clicks.


You ALWAYS re-checl black level after grayscale calibration and you may have to tweak Brightness. You use a black level evaluation pattern to set the Brightness control to get your black level set correctly. Once the pattern is correct, movies will be correct whether you think they are correct or not. Being used to how images look with the Brightness control set too high (shadow detail much too bright as a result) will throw-off your powers of evaluation. You always go back to the best black level pattern you have available. I much prefer a pattern with digital levels 0-25 or 0-30 over a PLIGE pattern that could be showing you 4 digital levels in 1 jump making the control adjustment much less critical. Much more precision in setting black level when you have a pattern with digital values from 0-25 or 0-30 so you can see each digital step and what it s doing.
 
This is an older thread, you may not receive a response, and could be reviving an old thread. Please consider creating a new thread.
Top