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The Official ChromaPure thread - Page 74

post #2191 of 4383
1/16/12 at 8:45pm
Quote:
Originally Posted by fahrenheit View Post

That certainly was the case last year when it was demonstated at the Value Electronics shootout. Even in the low quality youtube video it was plain to see. Blue was purple and orange was yellow.

A patch was supposedly being worked on but I've not heard whether it was released or if the problem has been addressed.

To be fair, I thought they were fairly specific in talking about the Cyan issues, which Kevin and Dwayne said a fix would be forthcoming (three months later, though nothing). The cyan issue is minor compared to the tracking issues I'm seeing.
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post #2192 of 4383
1/16/12 at 8:48pm
Quote:
Originally Posted by thrang View Post

To be fair, I thought they were fairly specific in talking about the Cyan issues, which Kevin and Dwayne said a fix would be forthcoming (three months later, though nothing). The cyan issue is minor compared to the tracking issues I'm seeing.

Ah ok. Seemed similar to what you were describing.
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post #2193 of 4383
1/16/12 at 10:16pm
Thrang:

There seems to be something fundamentally wrong with this set's calibration controls.

Please post an ACM report after using the user menu and the ISF menu calibration controls if you have the time.

What I still don't understand is why using the Mini doesn't fix all of this since it bypasses the Sharp's calibration controls entirely. It is unusual to say the least for local dimming to profoundly affect a display's colorimetry.

If you left one of the advanced local dimming modes on--which presumably would give you enough saturation to work with--could you not then use the Mini to do a proper calibration?
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post #2194 of 4383
1/17/12 at 4:44am
Quote:
Originally Posted by thrang View Post

To be fair, I thought they were fairly specific in talking about the Cyan issues, which Kevin and Dwayne said a fix would be forthcoming (three months later, though nothing). The cyan issue is minor compared to the tracking issues I'm seeing.

Posted yesterday:

Quote:
Originally Posted by KevinMiller at HDJ View Post

To answer an earlier post about the grass at thee shootout. I am not sure what happened but at some point the color saturation went way down on the panel at Value. I just did another one yesterday and I can tell you it looked great when I was done.

The original calibration report from the VE shootout looks fine save for magenta saturation. It's posted at the VE site.
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post #2195 of 4383
1/17/12 at 5:52am
Quote:
Originally Posted by thrang View Post

Hi Tom

Sorry I wasn't clear....

Initially, I had tried calibrating the set using several of the user modes (THX, Movie, etc.) using the standard CMS controls (not the ISF mode). This was after you have visited, and I did not get good results.

I also tried to use a Mini to calibrate these modes, but all of the initial RGB readings showed severely undersaturated unless I turned on Local Dimming, which brought the primary sats up some, but still way to low, or one of the Advanced local dimming modes, which shot the primaries way up. But all I've read is that those features should be turned off when calibrating, and in fact, when you enable the ISF mode, the set turns them off automatically.

The ISF mode is is different it seems, as I do not see the undersaturated primaries, and I thought all was going well (using the Greyscale and CMS in the Elite's ISF mode; gamma/greyscale tweaking was done in the Mini simultaneously, as there is no way to set gamma properly in the Elite alone)

They despite EXCELLENT numbers and charts, the colors looked off when viewing - watching the Rangers/Canandiens game showed that red was really magenta, and in fact, the ACM chart (which I did not save foolishly, but will run again and do so), showed a severe shift toward magenta, and the points themselves where way off. Same for all colors really; some 25/50 or 50/75 points were nearly bunched up on one another.

Skin tones were too saturated, yellows too pronounced... really odd.

I actually went back in and pulled Red hue and Magenta hue back more toward center from their more radical positions (to get Red "right" when calibrating, Hue was moved quite a bit to Magenta). This manual tweak helped somewhat, but the tracking is not right at all.

My next thought is to enable ISF mode, but leave the Elite Greyscale and CMS controlled untouched (expect White Point), and then run a Lumagen only cal and see what happens.

I do have the detailed calibration report, but if you were to read it, you would likely say fantastic!

I am on my third Elite because of DSE issues and my concerns over calibration - frankly, while they are about to send a fourth! set, I am really thinking there is something fundamentally wrong with the way this set decodes color. If you are still planning on supporting auto cal to the Elite directly, I'm curious what you will find

If you need to stop by again and spend more time to figure this panel out, you are welcome to do so...

Thanks

As I mentioned today in the Elite thread, check post 5486 on page 183. D-Nice posted his results on color tracking at various stim levels. Other than for cyan, the results look good to me.
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post #2196 of 4383
1/17/12 at 8:23am
Quote:
Originally Posted by dsinger View Post

As I mentioned today in the Elite thread, check post 5486 on page 183. D-Nice posted his results on color tracking at various stim levels. Other than for cyan, the results look good to me.

I don't think the issue is poor tracking at different levels of stimulus, but at different levels of saturation.
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post #2197 of 4383
1/17/12 at 8:28am
Quote:
Originally Posted by buzzard767 View Post

The original calibration report from the VE shootout looks fine save for magenta saturation. It's posted at the VE site.

I think that this is Thrang's point. Standard calibration numbers look great, but the image doesn't. A standard calibration report wouldn't show non-linear tracking at different levels of saturation, but it could have profound consequences for perceived color accuracy.

Note: I am only discussing this second hand. My experience with the set is very limited.
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post #2198 of 4383
1/17/12 at 10:52am
Quote:
Originally Posted by TomHuffman View Post

I think that this is Thrang's point. Standard calibration numbers look great, but the image doesn't. A standard calibration report wouldn't show non-linear tracking at different levels of saturation, but it could have profound consequences for perceived color accuracy.

....

I have this exact problem with my LG 47LH90. What works best is to make the CMS adjustments at 75% saturation. On my TV (and, I think probably on a lot of LGs) CMS adjustments have little or no effect at 100%. Typically, after calibrating/adjusting the grayscale balance and gamma I'll have dE of 2-5 at 75% saturations. Skin tones will have an orange or red tinge in some scenes. Adjusting at 75% saturations fixes all that.

Tom was kind enough to add the Advanced Color Management pane so that these measurements can be made and presented. I then use the AVSHD 709 disc (since my Duo won't produce 75% saturation test patterns) and the Raw Data panel to make the adjustments. That is, I do an AutoCalibrate and then finish with a manual tweaking at 75% saturations.
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post #2199 of 4383
1/17/12 at 12:49pm
Quote:
Originally Posted by rowland.johnson View Post

I have this exact problem with my LG 47LH90. What works best is to make the CMS adjustments at 75% saturation. On my TV (and, I think probably on a lot of LGs) CMS adjustments have little or no effect at 100%. Typically, after calibrating/adjusting the grayscale balance and gamma I'll have dE of 2-5 at 75% saturations. Skin tones will have an orange or red tinge in some scenes. Adjusting at 75% saturations fixes all that.

Tom was kind enough to add the Advanced Color Management pane so that these measurements can be made and presented. I then use the AVSHD 709 disc (since my Duo won't produce 75% saturation test patterns) and the Raw Data panel to make the adjustments. That is, I do an AutoCalibrate and then finish with a manual tweaking at 75% saturations.

Reading Tom's manual re 'Advanced Color Management' makes me realise just how complicated calibration can be.

75% saturation seems to work well for most people who have 100% sat. problems so why is 100% the normal pattern of choice with Displays?

I mean how much, as a percentage, does video need 100% saturation to be spot on? Surely lower values are used for most video footage.
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post #2200 of 4383
1/17/12 at 1:11pm
Quote:
Originally Posted by PE06MCG View Post

75% saturation seems to work well for most people who have 100% sat. problems so why is 100% the normal pattern of choice with Displays?

Because this is only a calibration problem with some displays that have non-optimal CMSs.

For example, both the Lumagen and Duo CMSs are fine using 100%. So are the Samsung internal CMSs. However, some display manufacturers either lack the budget or expertise to do the CMS right, and when this happens one of the consequences can be non-linear tracking throughout the color space. Good tracking at different levels of stimulus is usually not a problem.
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post #2201 of 4383
1/17/12 at 1:46pm
Quote:
Originally Posted by TomHuffman View Post

I don't think the issue is poor tracking at different levels of stimulus, but at different levels of saturation.

Tom: I will demonstrate my ignorance. Since D-Nice presented CIE gamut charts at various stimulus levels and the dots seemed to stay in the boxes with the exception of cyan, I thought that meant that both the saturation and hue tracked well throughout most of the 10-100 range for all colors except cyan.
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post #2202 of 4383
1/17/12 at 2:02pm
Quote:
Originally Posted by dsinger View Post

Tom: I will demonstrate my ignorance. Since D-Nice presented CIE gamut charts at various stimulus levels and the dots seemed to stay in the boxes with the exception of cyan, I thought that meant that both the saturation and hue tracked well throughout most of the 10-100 range for all colors except cyan.

A color at different levels of stimulus is just like the grayscale is with white. The goal with grayscale tracking is to keep white at 0.3127, 0.329 regardless of the level of luminance. We can do the same thing with color. A Rec. 709 red should stay at 0.64, 0.33 regardless of the level of luminance. That's what you are talking about, and this has nothing to do with saturation or hues.

The problem is that red, for example, can vary not only with respect to intensity, where the xy coordinates stay the same but the luminance varies. It can also vary in terms of how saturated it is. A Rec. 709 red is less saturated than a DCI red. These are completely different xy coordinates. Even if you stay within a prescribed gamut, such as Rec. 709, if you input a color that is 50% of the saturation of red (that is, half way between the gamut boundary and the white point) it should measure at just that point--half way between the Rec. 709 red and white.

The problem with some CMSs is that when you desaturate a color to bring it to where it needs to be it does not desaturate in a linear fashion. It brings a color that is 110% saturation to 100% saturation (which is what is measured), but it also brings a color that is, say 60% saturated, to 40% saturated. It may also shift the hues inside the color space as well. Since most of the color we see in normal program material is not fully saturated, all those shades of red will now appear wrong, sometimes drastically so.

Does this clarify the problem?

Identifying this problem is precisely why we developed an advanced color management module in ChromaPure. Without it, color can measure perfectly, but look awful. That is apparently what Thrang is seeing with the Sharp. This is not just a problem with cyan at different levels of intensity. It is much more profound than this.
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post #2203 of 4383
1/17/12 at 2:06pm
I'm going to try and start from scratch, and reset both the THX and ISF modes, and just do some straight readings as a baseline, including Advanced Color Management values.

Then I will do some internal and external (Lumagen Mini) calibration runs and post those.

Not sure if I can start this tonight or tomorrow, but will post as I go...
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post #2204 of 4383
1/17/12 at 2:09pm
Quote:
Originally Posted by TomHuffman View Post

Because this is only a calibration problem with some displays that have non-optimal CMSs.

For example, both the Lumagen and Duo CMSs are fine using 100%. So are the Samsung internal CMSs. However, some display manufacturers either lack the budget or expertise to do the CMS right, and when this happens one of the consequences can be non-linear tracking throughout the color space. Good tracking at different levels of stimulus is usually not a problem.

Thanks Tom,

Whilst the Displays CMS may be inadequate on some I think I may have a Display that will not allow full saturation of Blue so even my Duo will not help.

How often does this occur?
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post #2205 of 4383
1/17/12 at 2:20pm
Quote:
Originally Posted by PE06MCG View Post

Whilst the Displays CMS may be inadequate on some I think I may have a Display that will not allow full saturation of Blue so even my Duo will not help.

How often does this occur?

This is not uncommon. A CMS can only desaturate. It cannot create saturation where none exists. That is controlled by the display itself.
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post #2206 of 4383
1/17/12 at 2:41pm
Quote:
Originally Posted by TomHuffman View Post

This is not uncommon. A CMS can only desaturate. It cannot create saturation where none exists. That is controlled by the display itself.

With that scenario is technical correctness of all colors at 75% saturation preferable to 100% failure to calibrate blue?
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post #2207 of 4383
1/17/12 at 3:04pm
Quote:
Originally Posted by PE06MCG View Post

With that scenario is technical correctness of all colors at 75% saturation preferable to 100% failure to calibrate blue?

Impossible to say without knowing more.
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post #2208 of 4383
1/17/12 at 5:05pm
So Tom, I always calibrate my Epson 8350 to 75% Saturation patterns because of the PJ's CMS. I have been using the same patterns with the DUO.

Are you saying that I should just leave the Epson's CMS at zero and calibrate using the DUO's 100% patterns? This should give me a linear color space from 100% to 25%, as opposed to the wonky Epson CMS?

What about grayscale? should I just zero the Epson's gains and offsets and just use the DUO's 11 point controls?

(or just auto calibrate all 3 - Gamma, Grayscale, Color - in the DUO, leaving the Epson's controls at their default?)
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post #2209 of 4383
1/17/12 at 8:35pm
Quote:
Originally Posted by Kilgore View Post

So Tom, I always calibrate my Epson 8350 to 75% Saturation patterns because of the PJ's CMS. I have been using the same patterns with the DUO.

Are you saying that I should just leave the Epson's CMS at zero and calibrate using the DUO's 100% patterns? This should give me a linear color space from 100% to 25%, as opposed to the wonky Epson CMS?

Yes. I'd zero out the Epson controls and use the Duo for everything. You might need to get some help from the Epson at the low end of the grayscale.
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post #2210 of 4383
1/17/12 at 9:27pm
I just did a full auto-calibration with the Epson grayscale and CMS controls zeroed, and used the DUO for everything. It all went pretty well, but I had to go in to tweak everything manually afterwards. Grayscale was pretty much spot on, but Gamma was around 2.27 between 60-90 IRE, but I got everything down to 2.22-2.23 manually. Colors had around 1.8-2.3 dE, and I was able to get them all down below 1.0 manually, with the exception of Blue which I could only get down to 1.4 (couldn't lower x and y enough).

The auto-calibration is easily faster now with 2.2.10. All measurements were very stable across the board as well. Very pleased with the resultant image.
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post #2211 of 4383
1/18/12 at 5:38am
I think I have resolved whether I should use 75% saturation color patterns rather than the 100% ones for my 'Blue' challenged Toshiba LCD.

I used the excellent Advanced Color Management to diagnose my display's capabilities.

Generated two reports with my setup which is calibration via Duo only.

Report #1
Used Duo's patterns ie 75% Luminance, 100% Saturation for the calibration process.

Report #2
Used AVCHD patterns via Oppo 80 ie 100% Luminance, 75% Saturation for the calibration process.


However they indicate clearly that the average dE at 75% saturation calibration is superior for particularly blue as well as other colors.

Cannot reduce size of full .pdf file enough so hope this extract shows result.
LL
LL
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post #2212 of 4383
1/21/12 at 10:13am
I have a Sony Ruby, Radiance XD and an i1pro that I purchased in 2006 and used with Calman. I am considering a switch to ChromaPure for the auto cal feature but I have some questions.

1. Do I need to spend the $175 to have the i1pro recalibrated? I had read a post claiming that these are so stable that that is not necessary.

2. Will the low light sensitivity be good enough for the Ruby or do I need to also buy an Display 2/LT colorimeter?

3. I didn't see the Display 2/LT colorimeter listed as part of a bundle for those already owning an i1pro. Is it available from you and at what cost?

4. Would my cost be $200+100 for second meter license, plus $149 for auto cal assuming I need both the Display 2/LT colorimeter and i1pro?

5. I watched the demo. To "calibrate for dummies" do I check all three boxes and let it rip with 709 standard for blurry and Directv or are they calibrated to different standards?

Thanks,
Dave
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post #2213 of 4383
1/21/12 at 9:06pm
Quote:
Originally Posted by DaveN View Post

I have a Sony Ruby, Radiance XD and an i1pro that I purchased in 2006 and used with Calman. I am considering a switch to ChromaPure for the auto cal feature but I have some questions.

1. Do I need to spend the $175 to have the i1pro recalibrated? I had read a post claiming that these are so stable that that is not necessary.

2. Will the low light sensitivity be good enough for the Ruby or do I need to also buy an Display 2/LT colorimeter?

3. I didn't see the Display 2/LT colorimeter listed as part of a bundle for those already owning an i1pro. Is it available from you and at what cost?

4. Would my cost be $200+100 for second meter license, plus $149 for auto cal assuming I need both the Display 2/LT colorimeter and i1pro?

5. I watched the demo. To "calibrate for dummies" do I check all three boxes and let it rip with 709 standard for blurry and Directv or are they calibrated to different standards?

1. No.
2. Low-light sensitivity is not great. You might consider a Display 3, which is much superior to the Display 2.
3. It is obsolete. I can get it on special order, but I don't recommend it. See above. For prices, see our web site.
4. Yes.
5. Nope, just set it and let it rip.
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post #2214 of 4383
1/22/12 at 5:18am
Hi,

Simple question that has likely been answered but I don't know where to find it.

Are DVD files (for calibration) that Tom Huffman posted correct for 709 color space?

I thought DVDs were made to a different color space (for SD). My step father's blu ray player doesn't recognize AVS709 which is what I like to use and so I was thinking he may be able to use the DVD Files provided instead.

-Brian
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post #2215 of 4383
1/22/12 at 8:28am
Quote:
Originally Posted by Brian Hampton View Post

Hi,

Simple question that has likely been answered but I don't know where to find it.

Are DVD files (for calibration) that Tom Huffman posted correct for 709 color space?

I thought DVDs were made to a different color space (for SD). My step father's blu ray player doesn't recognize AVS709 which is what I like to use and so I was thinking he may be able to use the DVD Files provided instead.

-Brian

Burn the AVSHD Disk to a BR-R Disk. DVD (SD) has different gamut targets, your player with convert them to REC709 (HD) but you are not sure if it's doing that conversion with the right way.
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post #2216 of 4383
1/22/12 at 10:24am
I don't have a Blu ray burner. I'll bring DVE which is lame compared with AVS709 but at least it will work.

(Sorry for the tangent, we can delete these posts if needed.)
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post #2217 of 4383
1/22/12 at 10:44am
Quote:
Originally Posted by Brian Hampton View Post

I don't have a Blu ray burner. I'll bring DVE which is lame compared with AVS709 but at least it will work.

(Sorry for the tangent, we can delete these posts if needed.)

DVE Blu-Ray features only Grayscale patterns, Color Gamut Patterns are missing.
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post #2218 of 4383
1/22/12 at 10:56am
Quote:
Originally Posted by Brian Hampton View Post

I don't have a Blu ray burner. I'll bring DVE which is lame compared with AVS709 but at least it will work.

(Sorry for the tangent, we can delete these posts if needed.)

You don't need a Blu-ray burner to burn the AVSHD ISO. There is a download that is in AVCHD format that will burn to a regular DVD. It plays in the majority of Blu-ray players and is in native Rec. 709 color space.
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post #2219 of 4383
1/22/12 at 11:40am
Yeah, my stepdad has one of the players that won't play avs709. Sucks.

(it would likely play the Blu ray version but like I said I can't make one of those.)

Edit 2- I think I'll make the USB drive file version,... Maybe his player will play it that way.
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post #2220 of 4383
1/22/12 at 11:54am
Quote:
Originally Posted by Brian Hampton View Post

Are DVD files (for calibration) that Tom Huffman posted correct for 709 color space?

I thought DVDs were made to a different color space (for SD).

This is a subject that causes much confusion. Test patterns do not embody a prescribed gamut. That's a characteristic of the display. For a red test pattern, for example, the disc just tells the display to show 100% red, 0% green, and 0% blue. What actually appears on the screen is controlled by the display's native primaries.
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