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Discussion Starter #1 (Edited)
Free LightSpace DPS (now LightSpace ZRO) - Manual Display Calibration

For those of you using the Free DPS version of LightSpace CMS, with the help of a bunch of Beta Testers, we have written a user Guide on Manual Display Calibration.

This is still a bit work-in-progress, but it's close enough to finished that it's worth linking to.

http://www.lightillusion.com/manual_calibration_idiots_guide.html

If anyone spots errors, omissions, grammatical issues, etc, feel free to flag them up!

Steve
 

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If anyone spots errors, omissions, grammatical issues, etc, feel free to flag them up!
Thanks for sharing. I have not tried the software, but have some comments on the guide based only on a cursory look:
1. There are four pictures showing potential display issues. The 4th one is mislabeled - it should be "Bad RGB Balance", not "Bad Gamma" (which is the 2nd picture).

2. "SET BLACK AND WHITE LEVELS".
- For the first option (using Direct HDMI and CalImages), I find the description confusing. It refers to setting to the TV Legal Range of 16-235, but I suspect it should instead refer to the full PC (or Data) Range of 0-255. The subsequent statement "meaning there will be no 'below black' or 'above white' bars as used from Disc sources" would be valid only for 0-255.
- For the second option (using Calibration Disc). As long as you are achieving the desired target luminance, there is no need or benefit in pushing the Contrast all the way up to make the 236 and above disappear. To high a contrast can cause other issues such as discoloration or colour clipping.

3. "SET PEAK WHITE". The illustration is not showing.

4. "SET GREY SCALE BALANCE". The two "rules of thumb" cannot be "combined". If (1) Green is not to be touched, and (2) RGB values should never be increased, then it would be impossible to correct for an excessive of Green, which is a very common problem with projector lamps.

Typos:
"THE TOOLBOX, Patch Generator". "Form most calibration work" should be "For most calibration work"
"THE TOOLBOX, Calibration Test Patterns". "... enables the calibration disc to be automatically play ..." should be "... enables the calibration disc to automatically play ..."
"as closing LightSpace DPS will loose (lose) any and all profile data collected"
"If desired a second or even third Quick profile can

If I have time I will try out the free Lightspace DPS and check it against the guide.
[EDIT: The program does not seem to work with the retail version of i1D3, which is what I have].
 

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Discussion Starter #3 (Edited)
Thanks Dominic, have made the obvious changes/corrections.

I'll work on making the 'Set Black and White Levels' easier to understand.

And good point on the 'Super White' clipping for some home TVs. I'm actually more use to professional displays, and they have specific settings for Data range and TV Legal (0-255, 16-235).

For home TVs it really depends on how the 'Contrast' control functions, compared to a 'Backlight' or 'Iris' type control.

As for the i1D3 question, please e-mail ConnecTED - http://www.displaycalibrations.com/contact_us.html

Steve
 

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Discussion Starter #5
I should probably also say that we are aware of some of the limitations with the present 'Calibration Interface' GUI within LightSpace CMS, and we are working on those issues.

As a sneak-peak... at the moment the bar graph is not functioning correct, but you get the idea.

Steve
 

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As a sneak-peak... at the moment the bar graph is not functioning correct, but you get the idea.
Displaying the bar graph would be a welcome change. The current scheme relies on the user to adjust the RGB controls by looking at the x,y values, which is next to impossible for new users.
 

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The manual is really looking good. I have always been impressed with LI website and the great information it provides. Since the new site overhaul it has improved greatly and now this additional guide. Thanks!
 

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Excellent work. Thank you for offering a free trial version, as I was interested in the software but was not willing to invest the money, only to find out that I may not like it.

I notice that for the DeltaE options that only 1976 and 2000 are offered. I am curious as to why 1994 was dropped.

With regards to legal television range 16~235, I agree with you. I have read this thread and agree with the individual. The Burosch video supports your statement of setting white levels. Since there really is no video content in the super white area, diminishing the "pop" factor of the image to try and view content that is not there seems senseless. The "Super White" features built into various consumer grade displays gravitate to the computer arena as opposed to the television arena. This function seems to be utilized for secondary devices such as the PS3. The statement regarding color shifting is a valid one, but this is due to the poor engineering of the display's controls. Even with displays with these deficiencies should still strive to get as close the the legal range as possible. All in all, we can all agree that the legal range is 16~235 and not 16~254.

Keep up the excellent work.
 

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Discussion Starter #13
I notice that for the DeltaE options that only 1976 and 2000 are offered. I am curious as to why 1994 was dropped.
1976 is basically the 'original' Delta-E colour difference formula, and many users still refer back to it.

1994 attempted to correct for the perceptual non-uniformities with 1976, but basically failed due to a lack of reference data.

2000 correct this failure with refined definitions, and as a result is more perceptually uniform.

We therefore do not use 1994, as the data used has proven to be less accurate than 2000.

Hope that helps.

Steve
 

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1976 is basically the 'original' Delta-E colour difference formula, and many users still refer back to it.

1994 attempted to correct for the perceptual non-uniformities with 1976, but basically failed due to a lack of reference data.

2000 correct this failure with refined definitions, and as a result is more perceptually uniform.

We therefore do not use 1994, as the data used has proven to be less accurate than 2000.

Hope that helps.

Steve
Thank you for the quick reply and the information.
 

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I'll work on making the 'Set Black and White Levels' easier to understand.
On the setting of white level, the guide states that
there are (presently) no consumer sources that ever contain valid content that is below 16 (64), or above 235 (940), so calibrating a home TV to 'allow' for Super White is just limiting the display unnecessarily, with no 'image' benefit at all - in fact, the exact opposite.
This statement seems to be at odds with the posts by Stacey Spears and Don Munsil:
http://www.avsforum.com/forum/139-d...y-above-white-does-not-clip.html#post16498326
http://www.avsforum.com/forum/139-d...above-white-does-not-clip-2.html#post16498839

In the same thread there are also those who question the "visibility" of whiter-than-white, but that's a separate argument.
 

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Discussion Starter #19
That looks just like 'compression ringing' and/or 'bit level inaccuracy' in the playback device to me.
I see no valid image detail there.

I have mastered a lot of material for TV and Disc delivery over the years.
(I have worked exclusively in the professional film and TV industry all my working life)
No broadcaster or mastering facility will ever accept master material with 'illegal' levels - and that means outside the 16-235 range.
there is a whole subsection of the broadcast industry dedicated to signal level verification.

Steve
 

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No broadcaster or mastering facility will ever accept master material with 'illegal' levels - and that means outside the 16-235 range.
there is a whole subsection of the broadcast industry dedicated to signal level verification.
For the 16-235 range, are you referring to the Y component of YCbCr, or to the R/G/B values? A (legal?) YCbCr value of 230-128-128 corresponds to R-G-B of 249-249-249.
 
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