The Official ChromaPure thread - Page 128

Hello, How do I check to see if it's better for me to calibrate my gamut at 75% saturation then 100% saturation. What set of patterns do I use to do a full tracking of the gamut? I am using the GCD disk and Chromapure. Can you give me an example? I have a D6500 Samsung plasma. My gamut currently is calibrated to 75%a/100%s.

Not meant as harsh as it maybe sounds: its actually described in the chromapure manual. Use the advanced colomanager and see what makes the colors track beter, 75 or 100% calibration.

I think that I have the grayscale and gamma set up reasonably now and am starting in on color gamut. I am wondering if anyone can help me find 25, 50, 75% color screens (test patterns?) so I can use teh ACM module. I have been using the AVSHD files from here but I think they only have 100% and 75%.

Thanks!

patterns are in ColorHCFR/Saturation folders...

Cgd on this forum

http://www.avsforum.com/t/1406352/gcd-gamut-calibration-disk

What patterns do I put up from the GCD disk? Say for red is it 75%a/25%s, then next 75%a/50%s, 75%a/75%s and finally 75%a/100%s is it the saturation sweep patterns but keeping luminance constant?

henryoh:
I am partially skilled, no guru in any case, but may I give to you some advice ? If so, here is something I have learned by myself, confirmed by reading any possible forums, studying writings from masters like Tom...

Do calibration in SMALL steps. this is iterative process, each change can affect other setting. If you get something like this ( on 10pt white balance)

...
7 : 4,-3,-5
8: -4,6,4
9: 3,-1,-6
...

something is wrong. In Gamma module (go from 10 to 90 after initial reading), if you change settings at 30, go back and check 20, maybe then check at 10. Do small steps. Then reset form, take another reading to have proper value at 100%. If you have extremes, like in above examples, try to take 5% readings...and generate reports

Thanks for the advice. I experienced this in conjunction with some prior advice that Interval 2 doesn't EXACTLY line up with 20% grayscale. I moved around the blue in Interval 2 a number of notches and it was WAY too much. It also impacted 30% grayscale. I also noticed that adjustments at the dark end (10, 20, 30% grayscale in case I am using the word dark incorrectly) were much more sensitive to movements in the 10p White Balance Intervals than the light end (80, 90%). Is this generally a truth or just something that happened for me?

The same as with my ES6710 - sammy led tv.

Just dove into the Advanced Auto Calibrate for the first time last night and had a few basic questions.....

1. Should I choose 5% or 10% for the gamma increments?

2. Is there any reason to have both boxes checked for color gamut AND advanced color gamut or should I just check advanced color gamut and leave color gamut unchecked?

1: see what works. For me doing 5% screws up my black.

2: just 125, leave the rgbycmw

Which reminds me, Tom, I would like to request the possibility to select or deselect the inbetween 5% gamma/greyscale points with autocalibration, equal to the way you can in manual. I would like to leave the 5% alone since attempting to calibrate that seems to mess up my 0% white (black, duh)

Thanks. I will try 10% today as I was using 5% last night. I will also just check 125, not both.


Also, I was just reading through part of this lengthy thread and it seems Tom strongly suggests using full field patterns instead of windows for front projector users with the D3 reading off the screen.........is this still the case? I was using windows last night, but should I switch to full field patterns instead?
Edited by Toe - 1/18/13 at 10:36am

10% increments
Full field test patterns for projectors
If you are doing 125 point, then Color Gamut is unnecessary.

Thanks Tom!

First time user of ChromaPure here so please cut me some slack on the newbie post....I am going through the Advanced Color Management Module to see if I should use75% or 100% saturations for color calibration. I have patterns from the AVSHD disc available on this website and I am wondering when I go to measure amplitude (step 9 on page 52 of the Chromapure manuel) in 25% increments do I just use the saturation patterns that I just used for steps 5 6 and 7 or are there specific ammplitude patterns?

Here is a screen shot of the color management module color management.doc 211k .doc file at 100% saturation. Can someone help me interpret what this means I need to do now? I want to minimize dE, I get that. For say, Blue which has a dE of 4.4 is the graph saying that my blue has 22.3% too much blue in it? Accordingly I should reduce the amount of blue in my Blue in the CMS?

I have tried to upload the ACM Report, but it keeps stalling, I presume it is because it is too big. Is there a specifci part of the ACM Report that would be instructive in makkng the decision to calibrate color at 75% or 100%?
Edited by rocketman9 - 1/22/13 at 1:05am

Don't know about anyone else but I used the internal patterns within Chromapure when using Advanced CM..

These I showed on my Display by HDMI connection.

As I understand the process, it is necessary to run the program from Chromapure when you have calibrated using your 100% saturation patterns (via AVS disc) then compare the average dE results on the report when you have recalibrated using 75% saturation patterns (via AVS disc) and run the report again.

Thats what I had to do and from the results of the two reports I was able to ascertain that my Display would probably benefit from 75% calibration.

Sorry if things have moved on a bit since I did this (some time ago) but that was my method..

Are there any plans to add lower gamma options to auto cal? Or maybe the better question is why is 2.2 the lowest gamma option there is?

Thanks

Looking for some general hints and tips about meter profiling. I have a D3 Pro and an i1 Spectro. I wish when you were on the Auto Cal screen it would identify which meter is being used for example: Field meter in use (D3 DLP Mode) or something like that.

I want to use the spectro to train the D3 Pro. What table should I initialize the D3 with when I am going run Meter Correction. Last night I used the DLP Rear Projector ( I have a big DLP) mode but I wonder if that just complicates things as opposed to using CRT or Plasma.

Also how much effort should be spent on trying to match the measuring method between the two meters. Since there is no effective aiming mode for either meter.My stap for the spectro which I recently aquired is to short for contact mode.

I normally use the D3 Pro about 10 inches off the screen as close to center as I can eyeball. Becasue of the way the tripod mount is on the spectro.. that requires moving the tripod and of course reposition the tripod head. I am using fields on a 92" display.. so there is going to be a little difference in the target spot and the two probes FOV are different. How big an effect is that going to make? I guess I am asking what would practice and how futzy to I need to be with the target aiming and distance and method?


BTW, I am using a Lumagen and 125 Point Auto-Calc. I tried just using the spectro but twice it hung at the same color about 2/3 rds of the way through. I did get a pretty decent calibration last night with my somewhat haphazard meter profiling. Display measured well and looks good. I use a wide gamut mode as a starting point so there a good number of reads and it takes nearly an hour with the D3 Pro to complete.

Comments and feedback would be very helpful.

BT.1886 goes below 2.2 at the low end. Otherwise, I can think of no reason why one would ever calibrate to a target lower than 2.2.

Hi, you need to get all three controls RGB as close to zero % as possible for all the primaries and secondaries this will reduce your delta E. However pay close attention to which combinations of error gives you a more accurate color overall. This is also mentioned in the help guide . I use the Gamut Calibration Disk or GCD. If your are calibrating to 75% saturation then use 75%amplitude/75% saturation otherwise the standard is usually 75%amplitude/100% saturation. In your case it seems like you are better off with 75%saturation patterns. I don't use the AVS disk.

Tom,

I was wondering if you would considder adding BT.1886 as a gamma option to manual calibration?

I am sure that we will do this at some point, but it would only provide calibration targets and they are easily available now.

yes I know but would be easier having it done in Chromapure and not have to use a seperate spreadsheet, but yes not important, but would be helpfull

Thanks. I was curious more than anything as I know some actually like to run a lower gamma as an option for certain things like daytime viewing.

As far as the BT.1886, I did a search and read up a bit about this option and from what I gather it is best to override the white and black luminance, correct? If so, how exactly do we figure out the values we need?

Also, if we choose the 1886 is there any preference on how to do this with the auto cal? Should we do greyscale/gamma first, then the 125 point or can we just do all of it in one shot still?

Thanks

You measure them. If you have 125 point, grayscale/gamma then 125 point.

Ok, I am slowly, oh so slowly, downloading the GCD.

I am sure this is just a terminology thing, but is amplitude the same as luminance?

Thanks. Measuring 100% white should be reliable, but will measuring black on my RS45 at the screen be doable? I thought I read that readings down that low are not reliable, or do I have this wrong?

So this might be a dumb question, but from my Color Managment file attached above is it fair to say that looking at Green, I need to go into Custom Color Green and DROP the green setting and increase both Red and Blue? It just seems odd to add red and blue to my green to make it right....

The documentation in CP is really pretty good, so I encourage everyone to take advantage of it. Quoting from the Help file (Using Auto-Calibrate, BT.1886 Gamma) "If you have a JVC projector whose black level you cannot read, then simply measure the contrast ratio by pointing the probe at the lens (using a diffuser). Once you have the ratio between black and white, just take a reading from the screen for 100% white, then you can calculate the black level from this."