Author Topic: Greyscale/Gamma Calibration Tip  (Read 4742 times)

Offline idm

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Re: Greyscale/Gamma Calibration Tip
« Reply #45 on: May 18, 2016, 09:00:32 AM »
EDIT: It might be interesting to compare the two modes across the THX preset and my own calibration - and to compare my THX results with those of reviewers who've measured the panel with their Klein 10As. Only if you're keen to see, wouldn't just do it for fun.

Not to sure what you are suggesting here, but I am always open to suggestion. I would like to, in the near future, perform some measurements and post them here to partly support what I mentioned at the beginning of the thread and also to demonstrate the different measurements obtained from the pro2 and d3.

I understand what you are saying about the sub field, reason your d3 sees your display as a crt and agree with your reasoning. But you can never be sure, if I may suggest you pose the question on the Calman forum, lots of pro calibrators there that could confirm or offer good advice as far as the accuracy across meter modes and thx presets is concerned for the d3 and your display. That forum has been extremely quiet lately, and it seems to be taking forever for the next software update to be released.

Forgive my ignorance but is your display 4k? You made mention of DCI, red phosphor covering 98%?

Offline KenMasters

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Re: Greyscale/Gamma Calibration Tip
« Reply #46 on: May 18, 2016, 10:15:22 AM »
Not to sure what you are suggesting here, but I am always open to suggestion.

I thought it might be a good way of ballparking accuracy - looking through reviews though there's too much variance for using their readings as a benchmark.

I would like to, in the near future, perform some measurements and post them here to partly support what I mentioned at the beginning of the thread and also to demonstrate the different measurements obtained from the pro2 and d3.

I understand what you are saying about the sub field, reason your d3 sees your display as a crt and agree with your reasoning. But you can never be sure, if I may suggest you pose the question on the Calman forum, lots of pro calibrators there that could confirm or offer good advice as far as the accuracy across meter modes and thx presets is concerned for the d3 and your display. That forum has been extremely quiet lately, and it seems to be taking forever for the next software update to be released.

I think I am signed up on there but don't think I've ever posted. I'm on forums partly due to my interess but also to keep in touch with S.A.  I don't really need any confirmation, I'm happy with the results and feel pretty confident in them. I might feel differently when I purchase a new display, I'll see what options are available for Ultra HD panels when the time comes. I did consider picking up a Pro 2 after talking through this thread but still can't justify the price to myself, if it was a reference device and I could be sure it was accurate then that would be another story but as is the price is high for something that likely may but also may not be giving me better results.

Forgive my ignorance but is your display 4k? You made mention of DCI, red phosphor covering 98%?

No, it's a 1080p HDTV but it does accept 10bit colour and features a DCI colour space option.
« Last Edit: May 18, 2016, 10:42:30 AM by KenMasters »

Offline KenMasters

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Re: Greyscale/Gamma Calibration Tip
« Reply #47 on: May 19, 2016, 04:03:01 PM »
I visited the SpectraCal forum to see what others experiences were with the VT60, I'm not alone, a number of threads discussing a green tint when using the plasma meter mode. A user on one thread mentioned LCD CCFL being a better match. Last night I couldn't sleep, ended up thinking about how best to figure out the right meter mode, so I got up, broke out my Pantone swatches, test discs and cranked up the backlight.

I took readings of the THX preset and my calibrated settings, looked at review readings and compared colour chips, I then started comparing measurements of likely offsets and zoned in on CRT and Raw XYZ as those readings that best concured with what I'd established as the ballpark. Left CRT calibration on ISF Day and did a Raw calibration on ISF Night - the two were very similar with red being the key differentiator, CRT still being a little too cool, so Raw XYZ for me it is. Back aches today, a lot of damn work for a relatively minor perceptual payoff, sat there from 12am until six this morning.

EDIT: Looking at the correction chart on page two it makes sense. There's a relatively large negative offset for plasma green - not unreasonable to think Spectracal's tables are similar. CRT's offsets also make a lot of sense in context.
« Last Edit: May 19, 2016, 04:25:18 PM by KenMasters »

Offline idm

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Re: Greyscale/Gamma Calibration Tip
« Reply #48 on: May 20, 2016, 01:37:36 PM »
What correction chart on page 2 are you refering to?

Offline KenMasters

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Re: Greyscale/Gamma Calibration Tip
« Reply #49 on: May 20, 2016, 01:42:55 PM »
What correction chart on page 2 are you refering to?

Chromapure's compensation values.

Offline idm

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Re: Greyscale/Gamma Calibration Tip
« Reply #50 on: June 30, 2016, 07:39:52 AM »
Some results 3d cube results from quite a while back, planning to do another one soon, especially with the most recent updates for Enthusiast.


















Offline KenMasters

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Re: Greyscale/Gamma Calibration Tip
« Reply #51 on: June 30, 2016, 08:49:22 AM »
Nice! I have these results I took yesterday testing out the ColorMatch function, but will take luminance and saturation sweeps later today:


Offline KenMasters

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Re: Greyscale/Gamma Calibration Tip
« Reply #52 on: June 30, 2016, 10:43:37 AM »
There we go:


Offline idm

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Re: Greyscale/Gamma Calibration Tip
« Reply #53 on: June 30, 2016, 04:48:15 PM »
Are you using Calman generated patterns for the colour checker? I have to use Calman patterns for the cube measurements and then double check with Ted's disk from an Oppo BDP 83.

A lot of times I have problems getting the right output levels from the laptop, have to play around a bit to get it right.

Offline KenMasters

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Re: Greyscale/Gamma Calibration Tip
« Reply #54 on: June 30, 2016, 06:15:36 PM »
Are you using Calman generated patterns for the colour checker? I have to use Calman patterns for the cube measurements and then double check with Ted's disk from an Oppo BDP 83.

A lot of times I have problems getting the right output levels from the laptop, have to play around a bit to get it right.

Yea, video output from laptops/PCs is dicey.

The nice thing with the Panasonics is they interface with CalMAN directly, put in the TV's IP address and the picture controls are integrated into the program, program speaks to MobileForge which sends patterns to the TV - it's a nice closed loop. If you wanted to you could just set the parameters and CalMAN will run through calibration by itself. A godsend when it comes to calibrating the greyscale, does all the heavy lifting (though wouldn't trust it to be the end word).
« Last Edit: June 30, 2016, 06:23:22 PM by KenMasters »

Offline idm

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Re: Greyscale/Gamma Calibration Tip
« Reply #55 on: July 01, 2016, 04:31:14 AM »
Yup, I wish they had support like that for more common displays like Samsung and LG, a lot better in my opinion as it calibrates the innards of the display using features normally difficult to get to with other displays.