AVS Forum banner

Guide: GREYSCALE CALIBRATION FOR DUMMIES

77K views 264 replies 73 participants last post by  Pres2play 
#1 ·
Hi everyone!


I'd like to announce a new extensive guide I've put together.



Link: GREYSCALE & COLOUR CALIBRATION FOR DUMMIES »

(Update: It's no longer just greyscale calibration as I've added some new sections on colour decoders, primaries/secondaries, etc).


Over 250 hours of research and writing have gone into this guide.


This guide came about as the do-it-yourself (DIY) crowd has been asking more and more about greyscale and colour calibration over the years. With reliable colorimeters now under $150 USD and excellent free software like ColorHCFR available, it's a no-brainer that all DIY enthusiasts have some sort of colorimeter in their toolbox. If for no other reason than to better appreciate the complexities of colour calibration when they speak to a professional calibrator.


Countless number of calibration guides have been published prior to this one. Some of them quite good. The problem I found is that most assume that the reader already has the required equipment and knows exactly how to set it up properly. Most guides also assume that the reader has a good understanding of terms like D65, stimulus, CIE, etc. Some even provide links to highly technical documents as "required reading". Yes, many of these documents are very informative, but not everyone wants to earn a doctorate in colorimetry so that they can set their greyscale properly.


My guide takes a step backwards and makes the assumption that the reader has absolutely no knowledge of colour calibration. In fact, this guide assumes that the reader doesn't even *know* what "greyscale calibration" is! I explain what it is, why it's important, list the tools needed, where to get them, and walk you through the process from start to finish.


I hope you find it useful.


Comments and feedback are appreciated. I'm still tweaking portions of it as questions arise.


Kal
 
See less See more
1
#203 ·

Quote:
Originally Posted by Pres2play  /t/1029594/guide-greyscale-calibration-for-dummies/180#post_24373231


Kal,

I want to order a ChromaPure package. Which meter would you recommend for a curved OLED screen?

Great guide!

Bob
Hi Bob. If ChromaPure is what you're after, I'd recommend the ChromaPure + Display 3 PRO package .


Kal
 
#206 ·

Quote:
Originally Posted by Pres2play  /t/1029594/guide-greyscale-calibration-for-dummies/180#post_24378569


So I should get the i1 Pro bundled with ChromaPure Standard? Then add the i1 display pro meter?

This is an option but it's beyond most people's budgets. The i1Pro is a spectroradiometer that remains accurate (doesn't drift) as much or basically not at all. It lets you keep your calibrate i1 Display Pro (Display 3) meter accurate. For more info see the"FAQ: Which meter is right for me?" in my sig. Read the second on using 2 meters.
Quote:
Originally Posted by Pres2play  /t/1029594/guide-greyscale-calibration-for-dummies/180#post_24378607


Thanks, Kal. The ChromaPure site shows the bundles that are available. Which version of ChromaPure should I go with, OEM or Retail?

If you only want to calibrate TVs and projectors using ChromaPure, the OEM is fine. The retail boxed version also comes with X-Rite software to calibrate PC/MAC monitors automatically (.iCC profiles). Choose whichever works for you.


Kal
 
#209 ·

Quote:
Originally Posted by Pres2play  /t/1029594/guide-greyscale-calibration-for-dummies/180#post_24384335


Can you explain a little further the gamma calibration for sets that don't have 10-point gamma control? My display has presets (-3, -2, -1, 0, 1, 2, 3) and I can try each one, as you suggest, but which measurement mode(s) do I select in the Gamma module?

You don't select any mode. If all you have is gamma presets then use the gamma preset value that is closest to 2.22. In this instance since you don't have the 10pt gamma controls you just select the best gamma preset. That's all you can do. You need not to use the gamma module since you have no way of calibrating the gamma . Recheck brightness after changing the gamma.
 
#210 ·

Quote:
Originally Posted by kal  /t/1029594/guide-greyscale-calibration-for-dummies/180#post_24385949


Sorry, I don't understand what you mean by "which measurement mode(s) do I select in the Gamma module?" Can you explain?



Kal

It's not clear if I have to pick one of the measure modes (10%, 20% and so on) to find out which one of the presets will give me 2.2 gamma. According to Hungro, I don't choose any of the modes.
 
#211 ·

Quote:
Originally Posted by hungro  /t/1029594/guide-greyscale-calibration-for-dummies/180#post_24386139


You don't select any mode. If all you have is gamma presets then use the gamma preset value that is closest to 2.22. In this instance since you don't have the 10pt gamma controls you just select the best gamma preset. That's all you can do. You need not to use the gamma module since you have no way of calibrating the gamma . Recheck brightness after changing the gamma.

Don't use the gamma module at all? How will I know which preset will get me closest to 2.22? I should just change the gamma and recheck brightness?
 
#212 ·

Quote:
Originally Posted by Pres2play  /t/1029594/guide-greyscale-calibration-for-dummies/210#post_24386739


Don't use the gamma module at all? How will I know which preset will get me closest to 2.22? I should just change the gamma and recheck brightness?

I use Chromapure. By clicking the pre greyscale tab once it opens and you take a full 10pt greyscale measurement it will give you an average gamma value. Get this as close to 2.22 as you can by changing your preset value and then remeasure and check gamma again make sure to check brightness when changing your gamma preset value it could change then you'll have to readjust then measure and so forth. Just fallow the greyscale for dummies guide
but when it comes to gamma do the fallowing I told you. You might have to readjust the greyscale as well once you found the correct gamma preset. It's a lot of back and forth to get everthing calibrated.
 
#215 ·

Quote:
Originally Posted by Pres2play  /t/1029594/guide-greyscale-calibration-for-dummies/210#post_24388240


Kal,



I just watched a video of the grayscale calibration in real time at CurtPalme and it's pretty cool. Can wait for my package to arrive in a few days. Thanks for your help.

Oh boy you're in for a treat
)
 
#216 ·
Kal,


Just curious, I saw this in your article Colour Science: Understanding Gamma...The correct approach is suggested by the sRGB standard and has fairly recently been codified in a new gamma specification called BT.1886, which uses 2.4 as a starting point but adjusts the overall response curve depending on the black level and white level of the display. Like sRGB, BT.1886 recommends a gamma response that is higher at the top end than at the low end. A straight power curve of 2.4 is correct only if the display has a zero black level and an infinite contrast ratio, which no real-world display has....


OLED TVs have zero black level. Should I be targeting 2.4 gamma?
 
#217 ·

Quote:
Originally Posted by Pres2play  /t/1029594/guide-greyscale-calibration-for-dummies/210#post_24388919


Kal,


Just curious, I saw this in your article Colour Science: Understanding Gamma...The correct approach is suggested by the sRGB standard and has fairly recently been codified in a new gamma specification called BT.1886, which uses 2.4 as a starting point but adjusts the overall response curve depending on the black level and white level of the display. Like sRGB, BT.1886 recommends a gamma response that is higher at the top end than at the low end. A straight power curve of 2.4 is correct only if the display has a zero black level and an infinite contrast ratio, which no real-world display has....


OLED TVs have zero black level. Should I be targeting 2.4 gamma?

OLED TV does not have zero black level. Zero black level implies panel does not emit any light whatsover. Which current tech does not yet allow. Black level can be very low on top of the line pro panels, but don't confuse it with zero black
 
  • Like
Reactions: gus738
#219 ·
Some reviewers measured 0.001 for black on ANSI contrast pattern from a Samsung OLED, but also measured 0 CD/m2 from a full black pattern...could be some stray light from neighbouring white squares found their way into the probe or some ABL creeped in ...


Sent from my ALCATEL ONE TOUCH 6030X using Tapatalk
 
#220 ·

Quote:
Originally Posted by mytbyte  /t/1029594/guide-greyscale-calibration-for-dummies/210#post_24392713


Some reviewers measured 0.001 for black on ANSI contrast pattern from a Samsung OLED, but also measured 0 CD/m2 from a full black pattern...could be some stray light from neighbouring white squares found their way into the probe or some ABL creeped in ...


Sent from my ALCATEL ONE TOUCH 6030X using Tapatalk

I wonder what did they measure with, what were the conditions.
 
#221 ·

Quote:
Originally Posted by mytbyte  /t/1029594/guide-greyscale-calibration-for-dummies/210#post_24392713


Some reviewers measured 0.001 for black on ANSI contrast pattern from a Samsung OLED, but also measured 0 CD/m2 from a full black pattern...could be some stray light from neighbouring white squares found their way into the probe or some ABL creeped in ...


Sent from my ALCATEL ONE TOUCH 6030X using Tapatalk

You see this mentioned in all the reviews, and it's said OLED televisions are the only sets that can do this. It seems Samsung and LG are not doing a good job promoting this feature.
 
#225 ·

Quote:
Originally Posted by Pres2play  /t/1029594/guide-greyscale-calibration-for-dummies/210#post_24394463


I see only the presets -3, -2, -1, 0, 1, 2, 3

Hello, I think this can be enabled at movie mode only.
 
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