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Discussion Starter · #1 ·
Hello all,


I have attached My current settings for the Samsung PN58C8000. These reflect what I perceive to be the most film like for both HD content and DVD. I don't have blu-ray. I have gone thru a few calibrating sessions and noticed that even though the numbers "sort of" worked on paper the "look" of the panel was very contrasty and dark. Gray scale "depth" was limited. The attached settings appear to open up all the dark contrasty stuff and color is impeccable but the numbers/graphs still are not close to what I see others getting (especially gamma). I have attached these settings to this post and also the gray scale numbers and gamma graph. Basically after a number of attempts at just running the cal from the guides and ending up with a bright contrasty display I sat down and just looked at bunch of different content and manually set some initial levels (cel light, contrast and brightness) so that I was getting good brightness level overall and also most importantly good grayscale depth. I ran with those initial settings and did not change them and did a 2-point gray scale cal and then ran a full color cal which looked fine and views great. However when I run looking at the grayscale measurement numbers and graphs the resulting Gamma chart looks like the one attached. What can cause this and can it be corrected without losing my nice grayscale depth that I have now? Maybe it's the Spyder meter causing the wackiness?


Materials used - ColorHCFR 2.1, Spyder3 meter, GetGray SD Cal disk


Also after entering service mode once or twice I now notice that the 10 Point white balance doesn't seem to work anymore. I have the menus and sliders but operating the controls doesn't seem do anything to the levels. Is there something I need to do to re-enable this? In service mode all I really did was look around and didn't tweak anything.

I updated the display a few days ago to latest firmware 1030.1 and the 10p Wbal was working at that time. Only after going into and out of the service menu last evening does it now seem flaccid...


Thanks in advance for your help!



 

settings.txt 0.66796875k . file
 

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I'm not a pro, but have some experience with this display.


1) Look into the DVD player settings. It could be something with the DVD player causing the gamma drop. This shouldn't be happening with a peak output of 94 nits.


2) Try putting your contrast at 90-95. It's been reported that the 10pt adjustments don't work properly if the contrast is set too low.


3) Stay out of the service menu. There is no reason to go into it on this display.
 

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Discussion Starter · #3 ·
Even though the DVD player does have some controls there is nothing in its setup that is actually activated or doing anything to the video. All DVD controls are are verified as off. It has its HDMI output for video going direct to the display on HDMI-4.


The problem with setting Contrast too high is that grayscale depth disappears. Even though the cal numbers may indicate otherwise when viewing actual content the darker areas that I know have detail present in those areas are now cloaked in black. Hence I set those 3 controls by eye and balanced the rest of the calibration out using them and have a much better final Viewing result. Color wise it's perfect looking. I have noticed that the default numbers that some get (which I have tried on this panel) still seem to have reddish flesh tones. My setup here now has the best flesh tones I have seen from any of the other numbers I tried. Just wish I could get the graphs to look right...
 

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Quote:
Originally Posted by thghgv /forum/post/19529522


even though the numbers "sort of" worked on paper the "look" of the panel was very contrasty and dark.

Generally the measurements most people discuss are intended for dim rooms. I thought the newer Samsung displays have a gamma adjustment. Since you didn't like the look of the display, did you try lowering gamma? Assuming Y (lightness or brightness) from the meter is reasonable, the measurements would seem to indicate that you might be losing detail near white. My personal opinion is that if you don't like the look of a calibrated display then you might want to lower gamma, but keep it at least somewhat flat. Basically there's not much difference between 90% and 100% Y in your measurements.

Quote:
Maybe it's the Spyder meter causing the wackiness?

I've only used the i1 products so I can't really comment, but from what I remember from comparisons I wouldn't expect this sort of gamma measurement.
 

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Discussion Starter · #5 ·
Yes I have tried a gamma of -1 but it only seems to affect the lower 10-40% portions of the grayscale. Lowering the gamma just seemed to make the display flat and un-lifelike when viewing content. The only way I have been able to get a more consistent looking gamma graph is to reset the entire unit to default settings. The gamma readings are not totally flat but it more in line with a proper looking graph I have seen from others. However, none of the factory default settings look good to my eye, including the cal-day/night mode defaults. The factory color cals on all modes are just not centered at all. You can try messing with tints, and the color control etc but it never really looks correct. This is especially evident in the flesh tones. They appear ruddy and reddish looking no matter what one does with the coarse controls. The only thing that makes outstanding color on these displays is calibration. Plus those defaults put the display REALLY low on Y output. I mean really low, like around 10 ftL. Even in a dim/blackened room that is unwatchable for my taste. The display is definitely capable of the brightness I require, and by using the current settings is very accurate with regard to color and shows nice grayscale detail. I'm just wondering what the deal is with the gamma graph at this point.
 

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Discussion Starter · #6 ·
Ok here's something I found that I'll run by you all. My DVD player is set to "FULL RANGE RGB" as opposed to "RGB". My GetGray test disk is Standard Def DVD. ColorHCFR I have set to REC601 (SD colorspace). Could this be what is messing with the Gamma graph?


Given that my player can go either way "FULL RANGE RGB" or "RGB" is that the equivalent of REC709 as opposed to REC601??


As well, when I cal using the GetGray 1.1 disk with this player and HCFR what color space setting should I be using in HCFR? Could the wrong color space setting in HCFR cause the Gamma graph wackiness that I have been seeing?
 

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Quote:
Originally Posted by thghgv /forum/post/19535227


The display is definitely capable of the brightness I require

I'm just wondering what the deal is with the gamma graph at this point.

The simple calculation for gamma is the following:

(pattern percentage as a decimal) ^ gamma = light output compared to white


Let's say you want to use a lower gamma of 2.0, and ignore dim room compensation, so that the displayed image is somewhat similar to the original. This would be my definition of calibration, trying to make the displayed image similar to the original.


You can can calculate how bright 50% gray should be in relation to 100% white:

(50/100)^2 = 0.25


The above tells you that 50% gray should be 25% of the light output for white. You can relate 50% gray to white by inverting:

1/0.25 = 4


Using a gamma of 2 would mean that 100% Y should be 4 times as bright as 50% Y. Your current 100% Y is only 3.56 times as bright as 50% Y. Basically you need 100% Y to be more than 10% brighter for the current 50% Y to have a reasonable gamma. I'm not familiar with the controls the display offers to say if that's realistic.


Basically the gamma graph just relates how 10% though 90% compare to white (and black). Your 90% reading is about as bright as 96% would be for a 2.0 gamma. The gamma graph is telling you that you're running out of light output near white, because it's well below the 2.0 gamma that I'm suggesting as an ideal minimum.
 

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Discussion Starter · #8 ·
It seems that the DVD players color space settings makes a large difference on what this display renders with reference to gray-scale depth. I set the player to "RGB" space and did a cal with the GetGray SD cal disk. I was able to get a much better looking gamma graph this time. Overall gamma clocked in at around 2.19. I did another total factory reset from SVC menu and magically the 10p White bal works again. DVD content is stunning now that everything is set correctly. I transferred these same settings to the Sat STB, which is currently the only source of true HD content I have at the moment and it's totally brilliant. I'm still not sure if that DVD player setting of what appears to be color space, i.e. "FULL RANGE RGB", or "RGB" are in fact really color space settings REC709 and REC601 respectively. If true, Im at a loss to figure out why Pioneer would opt to put a HD color space setting on a device that plays standard def source material? All I know is, on this display using this player (it's a SD pioneer elite model) the "RGB" setting is what should be used to get proper looking video. Using the FULL RANGE RGB drops all the gray-scale depth and video level thru the floor. Anyone else ever experienced this before?

 

PN58C8000 Proper Settings.txt 0.8916015625k . file
 

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Quote:
Originally Posted by thghgv /forum/post/19541231


I'm still not sure if that DVD player setting of what appears to be color space, i.e. "FULL RANGE RGB", or "RGB" are in fact really color space settings REC709 and REC601 respectively.

In 8-bit there are 256 levels (0-255). Computers use 0 for black and 255 for white, which would probably be the full range setting. Typical video uses 16 for black and 235 for white, which would probably be the RGB setting. The information on the disc is actually YCbCr rather than RGB, and a majority of DVD players output YCbCr by default. Anway, the setting probably deals with the grayscale range the player outputs, and color space is something different.

Quote:
Originally Posted by thghgv /forum/post/19541231


Anyone else ever experienced this before?

I'm not familiar with the TV, but some displays require a settings change to accept the RGB range that computers use.
 
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