The Official ChromaPure thread - Page 216 - AVS Forum | Home Theater Discussions And Reviews
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post #6451 of 7446 Old 04-17-2015, 01:29 AM
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Dear TOM!
1) What %background APL and ARL in yuor wonderfull calibration disk?
2) Why in the gamma is not possible to separate output by color -red, green, blue?
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post #6452 of 7446 Old 04-17-2015, 02:26 AM
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Originally Posted by anta1974 View Post
Dear TOM!
1) What %background APL and ARL in yuor wonderfull calibration disk?
2) Why in the gamma is not possible to separate output by color -red, green, blue?
I don't understand the first question. APL is the average level for the entire screen, not just the background. I don't know what ARL stands for. In any case, the black backgrounds are 16. The APL patterns have an APL of about 25.
RGB Gamma is the same thing as grayscale. It is redundant.
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post #6453 of 7446 Old 04-17-2015, 09:55 PM
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Originally Posted by CalWldLif View Post
bt1886

Tried BT1886 and can't say I like the result. Maybe I'm doing it wrong. Color is awfully dull.
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post #6454 of 7446 Old 04-18-2015, 02:03 AM
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I tried BT1886 myself last week, but although I'd ticked the box to manual measure white and black levels it didn't seem to let me change them as they are greyed out. As they were at 0.003 and 120 I left them there and the autocal (using a Lumagen 2041 with 729 point CMS), but results were poor with quite a few dEs in the 'poor' range (about 5% IIRC) for the colour gamut.

I plan to have another go soon, but I need to know how to set the black and white levels before I try with BT1886 again.

"Don't believe everything you read on the internet". William Shakespeare 1615
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post #6455 of 7446 Old 04-18-2015, 04:23 AM
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Originally Posted by Kelvin1965S View Post
I tried BT1886 myself last week, but although I'd ticked the box to manual measure white and black levels it didn't seem to let me change them as they are greyed out. As they were at 0.003 and 120 I left them there and the autocal (using a Lumagen 2041 with 729 point CMS), but results were poor with quite a few dEs in the 'poor' range (about 5% IIRC) for the colour gamut.

I plan to have another go soon, but I need to know how to set the black and white levels before I try with BT1886 again.
You must enter your manual values for 0% IRE and 100% IRE in Options...there you will find BT.1886 and enter your own values.
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post #6456 of 7446 Old 04-18-2015, 07:46 AM
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Originally Posted by maximus74 View Post
You must enter your manual values for 0% IRE and 100% IRE in Options...there you will find BT.1886 and enter your own values.
I'm pretty sure I tried this as I changed the black level to 0.04 to see if it appeared on the autocal page with this setting, but it remained at 0.03.

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post #6457 of 7446 Old 04-18-2015, 08:57 AM
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I updated to the latest version. I have the impression there should be a "oled" mode for my display 3 pro meter, but I only see CRT, standard, front, plasma. Did I miss something?
what is the oled profile for chromaPure that other people talking about?
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post #6458 of 7446 Old 04-18-2015, 09:30 AM
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I did mine manually, with BT 1886 set to 0.003 and 120 in the Options box. In Gamma module, I picked BT 1886 and adjusted gamma at each stimulus to match the curve. The result was a noticeable dimmer picture with muted color scheme. May be BT 1886 is not suitable for OLED displays
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post #6459 of 7446 Old 04-18-2015, 09:34 AM
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Originally Posted by jh87 View Post
I updated to the latest version. I have the impression there should be a "oled" mode for my display 3 pro meter, but I only see CRT, standard, front, plasma. Did I miss something?
what is the oled profile for chromaPure that other people talking about?

You must send your meter to CP to have the profile installed.
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post #6460 of 7446 Old 04-18-2015, 10:37 AM
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Originally Posted by jh87 View Post
I updated to the latest version. I have the impression there should be a "oled" mode for my display 3 pro meter, but I only see CRT, standard, front, plasma. Did I miss something?
what is the oled profile for chromaPure that other people talking about?
Hi, you don't see the OLED table because when you bought your meter with PRO corrections, Tom was not offering the OLED table, so he hasn't compared your meter using his JETI to the LG OLED he has.

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post #6461 of 7446 Old 04-18-2015, 11:54 AM
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Originally Posted by ConnecTEDDD View Post
Hi, you don't see the OLED table because when you bought your meter with PRO corrections, Tom was not offering the OLED table, so he hasn't compared your meter using his JETI to the LG OLED he has.
I see. thanks
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post #6462 of 7446 Old 04-20-2015, 08:33 AM
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Dear TOM!
In chromapure 3 planned support 3DLUT with madVR?
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post #6463 of 7446 Old 04-20-2015, 08:33 AM
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Dear TOM!
In chromapure 3 planned support 3DLUT with madVR?
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post #6464 of 7446 Old 04-21-2015, 02:19 AM
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Originally Posted by anta1974 View Post
Dear TOM!
In chromapure 3 planned support 3DLUT with madVR?
Not in 3.0. This may be something we do in a subsequent point release.
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post #6465 of 7446 Old 04-24-2015, 03:40 AM
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Guys i have a question...

Im not proffesional calibrator or anything and the latest 30 days for only my use i have an X-rite i1 pro and i use HCFR to calibrate my 55ub950v so far without been able to be perfect according to hcfr without blaming HCFR offcourse which is total great, so my question is if ChromaPure will help me better... meaning if it has more control and help etc...

If yes then i suppose i need the Standard version right? and not the lite because i will miss the Gamma and the other things that standard has additional.

Thx
Chris
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post #6466 of 7446 Old 04-24-2015, 03:55 AM
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Im not proffesional calibrator or anything and the latest 30 days for only my use i have an X-rite i1 pro and i use HCFR to calibrate my 55ub950v so far without been able to be perfect according to hcfr without blaming HCFR offcourse which is total great, so my question is if ChromaPure will help me better... meaning if it has more control and help etc...

If yes then i suppose i need the Standard version right? and not the lite because i will miss the Gamma and the other things that standard has additional.
I would definitely recommend the Standard version over the Lite version. As to whether you will get better results with ChromaPure over HCFR, both are very good software and have many satisfied users. I and many people on this forum are available for support and our documentation is excellent.
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post #6467 of 7446 Old 04-24-2015, 03:59 AM
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Originally Posted by BlueChris View Post
so my question is if ChromaPure will help me better... meaning if it has more control and help etc...
Hi, If you like, you can check the well written and very useful manual of ChromaPure here: http://chromapure.com/ChromaPureManual.pdf
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post #6468 of 7446 Old 04-30-2015, 08:19 PM
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Any word on ETA for 3.0?
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post #6469 of 7446 Old 05-03-2015, 09:28 PM
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Any word on ETA for 3.0?
Some time in the 2nd quarter is about as specific as I can be.
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post #6470 of 7446 Old 05-09-2015, 08:58 AM
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Some time in the 2nd quarter is about as specific as I can be.
Tom,

If I purchase ver. 2.5.7 now what is the update policy? Will I be able to update to ver. 3.0 free of charge?
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post #6471 of 7446 Old 05-09-2015, 09:13 AM
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Tom,

If I purchase ver. 2.5.7 now what is the update policy? Will I be able to update to ver. 3.0 free of charge?
Hi, from 18 December 2014 until CP 3.0 Release Data, anyone who purchases a new ChromaPure 2.x.x license will be entitled to a free upgrade to v. 3.0 upon release.

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post #6472 of 7446 Old 05-09-2015, 09:26 AM
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Hi, from 18 December 2014 until CP 3.0 Release Data, anyone who purchases a new ChromaPure 2.x.x license will be entitled to a free upgrade to v. 3.0 upon release.
Thanks Ted
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post #6473 of 7446 Old 05-09-2015, 09:44 AM
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A couple more questions...

1. If I order the license today online will I receive it today?

2. Do I have to go through curtpalme for the better price?
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post #6474 of 7446 Old 05-09-2015, 11:17 AM
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A couple more questions...

1. If I order the license today online will I receive it today?

2. Do I have to go through curtpalme for the better price?
When you order through CurtPalme.com you are in fact ordering directly from Tom at ChromaPure. All orders go directly to him automatically, you are paying ChromaPure directly when you order at CurtPalme.com prices. Same products, same support.

Kal

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post #6475 of 7446 Old 05-09-2015, 10:35 PM
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Hi, Tom. Regarding the initialize module, it would be nice to have a box showing the active CRI mode for the CR-100.
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post #6476 of 7446 Old 05-17-2015, 04:41 PM
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I did mine manually, with BT 1886 set to 0.003 and 120 in the Options box. In Gamma module, I picked BT 1886 and adjusted gamma at each stimulus to match the curve. The result was a noticeable dimmer picture with muted color scheme. May be BT 1886 is not suitable for OLED displays
It is suitable for every type of display, but since the actual BT. 1886 gamma curve depends on the dynamic range there's practically no difference between calibrating an OLED display to BT. 1886 or calibrating it to a fixed gamma value of 2.4 (provided you do it correctly), because the dynamic range of OLED displays is near infinite. The dimmer picture is probably because it was first calibrated to a fixed gamma of 2.2, with BT. 1886 for black = 0.003 cd/m², white = 120 cd/m² and 8 bit studio swing (16-235) the gamma varies from 1.83 at 17 to 2.37 at 234. RGB 25 and above will be darker than the would be with a fixed gamma of 2.2, because the gamma value for those grey levels is higher than 2.2 with BT. 1886.

The BT. 1886 standard shows the largest difference compared to a fixed gamma value on displays with a fairly limited dynamic range, like LCD TV's, which often have a contrast ratio in the range of 1200:1 to 5000:1. If such a display were to follow the gamma curve for a fixed gamma value perfectly the dynamic range would have to be infinite, otherwise there would be a huge black crush. For 1200:1 and gamma 2.2 any RGB grey level below 25;25;25 for 16-235 studio swing would show as black, because ((x-16)/(235-16))^2.2 < 1/1200 for x<25 (integer). To solve this, the gamma value declines for grey levels below 25% on most TV's and displays. Thereby doing something similar to what BT. 1886 is meant to achieve. Because they already do this, BT. 1886 is very likely to not work properly, because the lower grey levels will be double compensated and therefore will be far too bright.
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post #6477 of 7446 Old 05-17-2015, 11:52 PM
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Because they already do this, BT. 1886 is very likely to not work properly, because the lower grey levels will be double compensated and therefore will be far too bright.
That wouldn't actually be true, would it? When you're calibrating an LCD and you measure the display the pattern already has that "compensation" applied to it. When you calibrate the LCD to BT.1886 you're just trying to make whatever sort of gamma curve the display presents conform more closely to the standard. Whether that gamma curve is a compensation for the LCD's limited dynamic range or not doesn't change that. The calibration process doesn't care why the display does what it does; it just tries to make the best of it.
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post #6478 of 7446 Old 05-18-2015, 12:34 AM
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It is suitable for every type of display, but since the actual BT. 1886 gamma curve depends on the dynamic range there's practically no difference between calibrating an OLED display to BT. 1886 or calibrating it to a fixed gamma value of 2.4 (provided you do it correctly), because the dynamic range of OLED displays is near infinite. The dimmer picture is probably because it was first calibrated to a fixed gamma of 2.2, with BT. 1886 for black = 0.003 cd/m², white = 120 cd/m² and 8 bit studio swing (16-235) the gamma varies from 1.83 at 17 to 2.37 at 234. RGB 25 and above will be darker than the would be with a fixed gamma of 2.2, because the gamma value for those grey levels is higher than 2.2 with BT. 1886.

The BT. 1886 standard shows the largest difference compared to a fixed gamma value on displays with a fairly limited dynamic range, like LCD TV's, which often have a contrast ratio in the range of 1200:1 to 5000:1. If such a display were to follow the gamma curve for a fixed gamma value perfectly the dynamic range would have to be infinite, otherwise there would be a huge black crush. For 1200:1 and gamma 2.2 any RGB grey level below 25;25;25 for 16-235 studio swing would show as black, because ((x-16)/(235-16))^2.2 < 1/1200 for x<25 (integer). To solve this, the gamma value declines for grey levels below 25% on most TV's and displays. Thereby doing something similar to what BT. 1886 is meant to achieve. Because they already do this, BT. 1886 is very likely to not work properly, because the lower grey levels will be double compensated and therefore will be far too bright.

Those gamma values match the readings I got. Does that mean I had the target gamma set to 2.2 and not BT. 1886?
Is it necessary to re-start Chromapure after making a change to the target gamma? The BT. 1886 gamma curve was visible in the gamma module.
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post #6479 of 7446 Old 05-18-2015, 06:57 AM
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That wouldn't actually be true, would it? When you're calibrating an LCD and you measure the display the pattern already has that "compensation" applied to it. When you calibrate the LCD to BT.1886 you're just trying to make whatever sort of gamma curve the display presents conform more closely to the standard. Whether that gamma curve is a compensation for the LCD's limited dynamic range or not doesn't change that. The calibration process doesn't care why the display does what it does; it just tries to make the best of it.
Depends. If you calibrate it yourself by using a 10 step gamma adjustment then no. If the TV has a built-in BT. 1886 setting and the manufacturer didn't pay close attention to this, then maybe yes. I don't know if there are TV's with built-in BT. 1886 settings, but I've recently tested an Eizo ColorEdge CG277 with a built-in BT. 1886 setting that was not correctly implemented.

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Those gamma values match the readings I got. Does that mean I had the target gamma set to 2.2 and not BT. 1886?
Is it necessary to re-start Chromapure after making a change to the target gamma? The BT. 1886 gamma curve was visible in the gamma module.
It sounds like you did calibrate it to BT. 1886 then. Maybe you just don't like the picture. BT. 1886 results in a quite high gamma value for most of the picture, which makes it quite dark. Therefore BT. 1886 works best in darker viewing conditions.

The dull colors are a result of a higher gamma value for the bright parts and a much lower gamma value for the dark parts.

Say that for instance you have the RGB color 80; 20; 20 (16-235 studio swing). In decimal RGB that is 0.2922; 0.0183; 0.0183.

With a fixed gamma value of 2.2 that results in 0.0668; 0.0001; 0.0001 gamma decoded RGB. With BT. 1886 with white = 120 cd/m² and black = 0.003 cd/m², that would be 0.0560; 0.0002; 0.0002.

Using the Rec. 709 gamut and D65 white point this results in:

Fixed 2.2 gamma xyY = 0.6366; 0.3300; 0.0143
BT. 1886 gamma xyY = 0.6339; 0.3300; 0.0121

This in turn results in:

dE2000 color difference = 1.71
DeltaH = 0.00%
DeltaS = -0.91%
DeltaL = -15.66%

Because the contrast ratio is already 40k:1 with white = 120 cd/m² and black = 0.003 cd/m² the decrease in saturation is not that pronounced. If you use BT. 1886 on an LCD TV with 1200:1 contrast (so 0.1 cd/m² black) the difference becomes:

dE2000 color difference = 0.90
DeltaH = 0.00%
DeltaS = -10.34%
DeltaL = +12.27%

As you can see the decrease in saturation by going from fixed 2.2 gamma to BT. 1886 gamma is now more than 11 times greater.
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post #6480 of 7446 Old 05-18-2015, 02:28 PM
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On the subject of BT 1886:

First, it is not necessary that a display has a 10 (or 20 point) Gamma Adjustment for BT 1889. If you only have RGB controls, Green has the largest impact on Luminance, so, for a given point, adjust G to bring the point to the proper Luminance, then tweak Red & Blue to restore balance. The ChromaPure gamma screen makes this easy.

I have an LG 60PN6900 (20 pt white balance adjustments) that I have calibrated Expert 1 for BT 1899, and Expert 2 for straight 2.2 Gamma. I did separate CMS adjustments for each . I am thus can easily compare the two settings. I have done the same for a customer's similar set. Yes, the BT 1889 appears a bit snappier, with noticeably better black detail. We both prefer the BT 1889 to the straight gamma.

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