Basic Guide to Color Calibration using a CMS (updated and enhanced) - Page 37 - AVS Forum
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post #1081 of 1936 Old 01-24-2009, 01:54 PM
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Quote:
Originally Posted by cvearl View Post

Have you ever looked at other peoples pre cal files? I have seen about 25 of them now. Apparently your's probably would have been fine without a greyscale adjustment if all the RGB's in your Greyscale progression were within 5% of pefect LOL. I would not even have bothered if I had dE's under 10 and my ramps looks fully tint free across the board and I was within 250K of D65 and was fairly linear. Some would have minded. I would not. You really should look at more pre cal files out there. Scary! Mine is good. Not great. But good.
C.

Come to think of it... My Sony was touted by CNET as having the most accurate color and grayscale they had seen up to that point. Still, many of the newer sets I have seen reviewed in the last year or so now seem as accurate or more accurate than my TV was out-of-the-box. Glad your calibration is working for you, but I have to admit there is a part of me that hopes more people will have the problem I am having (more the merrier) so that a solution can be arrived at sooner. I'm about tapped out on ideas.

Sean
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post #1082 of 1936 Old 01-25-2009, 01:35 PM
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To anyone in the field. I would be interested in hearing your opinion on this written by Kevin Miller at www.tweaktv.com

Of all of the major players in LCD flat panel television (Samsung, Sony, Panasonic, JVC, Mitsubishi, Vizio, LG, and Sharp) Sharp gets the award for the most calibration unfriendly LCD flat panel currently on the market.

Unfortunately, the service menu is so poorly designed that you can't accomplish anything in it. I and many another calibrator have braved the service menu of the Sharps over the last several years, and no matter how long you spend tweaking grayscale parameters you can never achieve a more accurate grayscale than what is available with the best preset color temperature in the User Menu, which depending on the model and year, is either Mid-Low or Low. You can imagine how pleased I was to find grayscale controls in the Advanced Menu where they had never been before. So at least I was able to get a reasonably good grayscale out of it without to much pain.

Well Sharp Giveth and Sharp Taketh away! They gave us grayscale controls, and they took out the most important part of a three tiered CMS (Color Management System). The color decoding has always been horrendously inaccurate in the Sharp LCDs, and this latest flagship model is no exception. In previous models with the CMS Value portion of the CMS menu we could get rid of the Red Push in the decoding, and get reasonably natural looking color and skin tones. Well Sharp took that tool out of the Advanced menu so now the only way to get rid of the Red Push, which shows up as obnoxiously overly pink skin tones, is to back the color control down, and severely under-saturate the color. This leaves a rather drab dull washed out looking color picture. It amazes me that Sharp doesn't take a look at their competitors, virtually all of whom have accurate color decoding in their sets and emulate that.

Recently I went to calibrate one of their flagship models, the LC-52SED94U, and after 3.5 hours of tweaking the panel I was so dissatisfied that I left the customer's house in disgust, and I couldn't in good conscience charge him as I didn't feel that the level of improvement was justified. I have now made it a policy that I will not take Sharp calibration jobs anymore as a result of this and many other disappointing experiences with Sharp LCD flat panel sets over the years. In any case if you are considering a Sharp Aquos LCD flat panel Caveat Emptor!

http://www.tweaktv.com/the-kevin-mil...he-market.html
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post #1083 of 1936 Old 01-26-2009, 04:08 PM
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Quote:
Originally Posted by cvearl View Post

Another thought crossed my mind... With ColorHCFR... When you "use the default zoom" for RGB in the chart, they all look really close to 100% At least closer anyway and also far more linear. I have zoomed in the scale on those screenshots for emphasis. When comparing to others out there, I have learned to look at what zoom the scale is at in their chart. 0 - 200% setting for the RGB scale makes my TV look almost perfectly linear and balanced. But zooming in the scale to 80 - 120 tells another story all together.

C.

Yes , ain't that the truth I see all these RGB plots and they look pretty good initially , but when you change the scale it allows you to see trends a lot easier. LCD will always produce something of an "S" curve . The newer models have a less pronounced example of this but it's still there .

Scott............

"Home Theatre is a Journey , not a Destination "
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post #1084 of 1936 Old 01-28-2009, 12:33 PM
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I have a concept I have been struggling with lately...Wide Color Gamut...are there any set values (or even recognized values) for the colors like there are for Rec 709 and 601?

many displays are using this concept with not having any way to correct color space...(Panny PZ85U for instance). I have calibrated 9 of these bad boys at work and they all look amazing, but the colors are slightly out of whack...once set as correctly as I can for the display, I still find myself dropping color setting 1 or 2 points to compromise for the oversaturation of red...

just wondering since my Samsung has 3 settings for color space, one of them being custom with RGB controls for all the primaries and secondaries...but the Panny's don't have that ability (although the higher end has better colors).

any thoughts?
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post #1085 of 1936 Old 01-28-2009, 02:24 PM - Thread Starter
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Quote:
Originally Posted by joeprocopio View Post

i have a concept i have been struggling with lately...wide color gamut...are there any set values (or even recognized values) for the colors like there are for rec 709 and 601?

Many displays are using this concept with not having any way to correct color space...(panny pz85u for instance). I have calibrated 9 of these bad boys at work and they all look amazing, but the colors are slightly out of whack...once set as correctly as i can for the display, i still find myself dropping color setting 1 or 2 points to compromise for the oversaturation of red...

Just wondering since my samsung has 3 settings for color space, one of them being custom with rgb controls for all the primaries and secondaries...but the panny's don't have that ability (although the higher end has better colors).

Any thoughts?

Digital Cinema (DCI)

Tom Huffman
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post #1086 of 1936 Old 01-28-2009, 04:32 PM
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oooo...YUMMY, 156 page .pdf file to ready through!

Thanks Tom.
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post #1087 of 1936 Old 01-29-2009, 10:01 AM
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Just out of curiosity what is Digital Cinema (DCI) that you are referring to.
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post #1088 of 1936 Old 01-30-2009, 05:26 AM
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Quote:
Originally Posted by shrabok View Post

Just out of curiosity what is Digital Cinema (DCI) that you are referring to.

http://en.wikipedia.org/wiki/Digital_Cinema_Initiatives
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post #1089 of 1936 Old 01-30-2009, 04:46 PM
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Quote:
Originally Posted by TomHuffman View Post

In the RGB color space red is defined as
R: 255
G: 0
B: 0

To desaturtate, you must move the color towards the white point. Lowering R doesn't do that. It moves it towards black--makes it darker. You can't increase saturation because that's a physical limitation of the way the system is designed.

However, now that I think about it, I believe that the Samsungs do allow you to increase lightness. I was confusing it with the Radiance CMS. If you build the CMS into the display, you have more flexibility over this parameter than you would have with a purely external system.

Hi Tom,
You mention about lightness and darkness. In the CIE chart
that would correspond to the vertical Y axis is that right? As you
increase lightness you move up the Y axis and as you decrease lightness
you move down?

Also is red push an error in the lightness or an error in the saturation?

Also does lightness have any effect on the gamma curve? I mean for eg: does increasing red lightness have any interaction with red gain?

Thanks
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post #1090 of 1936 Old 01-30-2009, 10:59 PM - Thread Starter
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Quote:
Originally Posted by gauras View Post

You mention about lightness and darkness. In the CIE chart that would correspond to the vertical Y axis is that right? As you
increase lightness you move up the Y axis and as you decrease lightness
you move down?

Also is red push an error in the lightness or an error in the saturation?

Also does lightness have any effect on the gamma curve? I mean for eg: does increasing red lightness have any interaction with red gain?

No. Lightness or brightness is perpendicular to the CIE chart. It isn't displayed there at all.

"Red push" is a loose term with no formal definition. However, it is more often referred to as a red primary that is too bright.

The lightness of the primary colors should be independent for the gamma/grayscale response.

Tom Huffman
ChromaPure Software/AccuPel Video Signal Generators
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post #1091 of 1936 Old 01-31-2009, 06:01 AM
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Quote:
Originally Posted by TomHuffman View Post

No. Lightness or brightness is perpendicular to the CIE chart. It isn't displayed there at all.

"Red push" is a loose term with no formal definition. However, it is more often referred to as a red primary that is too bright.

The lightness of the primary colors should be independent for the gamma/grayscale response.

Thanks Tom,
I understand the CIE a lot better, thanks for the excellent guide. Another question on gamma tracking.

All digital displays use some form of curve fitting algorithm to simulate the gamma curve of 2.2 to 2.5 to match the programming which is gamma corrected to match the CRT natural gamma of 2.5

So shouldn't all digital displays exactly track the gamma curve? The algorithm should always give an exact curve unless the display itself is where the gamma tracking can be off?

Considering a plasma, the electronics should drive all the plasma pixels the same for 0-100 IRE and all pixels should follow the luminance increase from 0-100 IRE. What in the panel (if it does) causes the gamma tracking to deviate from the ideal gamma curve of say 2.2?

Thanks
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post #1092 of 1936 Old 02-07-2009, 09:48 AM
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I have followed the curtpalme guide which seems very straight forward and intuitive. I am running into a problem which I am not sure is me or the Sony. When I make measurements to correct the greyscale my blue is up at 230%. Even with making the rgb corrections to the max the best I can get is %200.

is it me? Is it this panel? Is is the XBR6? Is it Sony?

Any help will be appreciated.

Thanks
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post #1093 of 1936 Old 02-07-2009, 04:13 PM
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Quote:
Originally Posted by MIKENBPT View Post

I have followed the curtpalme guide which seems very straight forward and intuitive. I am running into a problem which I am not sure is me or the Sony. When I make measurements to correct the greyscale my blue is up at 230%. Even with making the rgb corrections to the max the best I can get is %200.

is it me? Is it this panel? Is is the XBR6? Is it Sony?

Any help will be appreciated.

Thanks

Post your file? Pop it in a zip and do an attachment in your post.

Which meter? ColorHCFR? ect...

Panasonic 42" Plasma TH42-PZ85U
Panasonic Blueray Player DMP-BD35
Sony 5.1 Home Theater DAV-HDX475 (wish it was Panasonic but it's ok)
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post #1094 of 1936 Old 02-10-2009, 06:11 AM
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Quote:
Originally Posted by TomHuffman View Post

I don't have access to DVE Blu-ray, but I compared GetGray with an Accupel signal generator, and the differences were negligible.

BTW, there's no mystery about the Panasonic. Its red and green color points are oversaturated, presumably by design.

Sorry to be swinging a bat at a pile of unrecognizable twitching mass that was once a dead horse but in the document you attached, which is Getgray and which is Accupel? Before or After. If you remember that is.

Just wondering as I am looking at the "fL" numbers on the gamma page.

Thanks for putting up with me. If you don't remember, that's cool. Thanks again for posting this. I appreciated it.

Also. Is it possible to recall the meter?

C.

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post #1095 of 1936 Old 02-13-2009, 09:13 AM
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Sorry if this was explained already, but are the colors on the test pattern DVD attached in the tutorial SMPTE-C or Rec 709 colors? Or are both given?
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post #1096 of 1936 Old 02-14-2009, 02:56 AM
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I was wondering if anyone here was familiar with Sony's RCP System and had any tips/advice to share about using it?

I spent a few hours calibrating my new Sony HW10 projector yesterday with my i1Pro & CalMAN and am a bit unsure about a couple of things. Most of that time was actually spent getting the greyscale correctI was surprised at how difficult it was to get a linear greyscale from a 3-chip device. (I haven't worked with any before, but I would have thought it'd make things very easyapparently not) I also wish you could use ID3 for a custom gamma curve on the HW10, as I'm not entirely happy with any of the presets. Gamma correction off results in a "flat" 2.2 response, but it doesn't look good at all to my eyes. Gamma correction 3 is ≈2.4 and looks significantly better overall but that's too dark near black.

As with most Sony displays I've worked with in the past, it's a little disappointing when it comes to colour reproduction. You have the choice between a Normal/Wide colour space. Wide is what you would expectcompletely oversaturated, but it's disappointing that, for a display that is capable of covering the entire Rec. 709 colour space, the contstrained "normal" gamut is undersaturated.

As Sony's RCP CMS is only two-dimensional (RGBCMY chroma/hue) you don't really have any way of bringing the wider gamut under control with acceptable results so I ended up using the "Normal" colour space. Post-calibration, average dE'94 was ≈1.4 for Normal and ≈2.6 for Wide, and visually Wide did not look good at all in a lot of scenes. (I tend to prefer an undersaturated image to an oversaturated one)


Anyway, here's the post-calibration results. (note: I was only trying to see how close I could bring colour to Rec.709 yesterday, rather than using a custom colour target based on the primaries of the projector)



___________ Red____ Green__ Blue____ Cyan___ Magenta Yellow_  
RCP Colour +5 +2 -1 -1 +4 +8  
RCP Hue ±0 -15 +25 -1 +5 -1  
              Average
deltaE '94 1.01 3.02 0.80 2.43 0.90 0.32 1.41
deltaL '94 0.04 0.13 0.18 0.07 0.03 0.07 0.09
deltaC '94 5.50 8.6 5.26 7.02 5.06 0.90 5.39
deltaH '94 0.09 7.09 0.04 0.67 0.80 0.64 1.56

My first question is for anyone that's familiar with the RCP system. The range of adjustment on all controls is +/- 50, but even so, +25 for blue seems like a rather large adjustment. Are there any side-effects of doing this?

I haven't spent too long evaluating the image with these settings yet, but my initial impression is that it wasn't causing any problems.



My other question is a more general one rather than being RCP specific. I had quite a hard time making adjustments to green. The problem is that when you are adjusting hue in RCP, it also affects saturation. (and luminance to some degree) I used the colour adjustment to keep deltaL as low as possible when making these adjustments, but making changes to hue affected saturation in an almost perfectly equal and opposite amount.

So if I adjusted hue for green to be more accurate (deltaH <1) green was quite significantly desaturated, however, the overall deltaE '94 was almost exactly the same as deltaC had increased by the amount that deltaH had decreased.


In the end, what I settled on was adjusting hue so that deltaC and deltaH were as close as possible while keeping green inside the Rec.709 gamut. (if I took it outside the Rec.709 gamut I was able to get them both ≈7.6)

While this did shift green towards yellow a bit, visually this did not seem to be a big problemthe improvement to saturation seemed more noticeable.


Is this a failing of the dE'94 system? Surely there must be some way of objectively calculating the optimal balance between hue/saturation errors.


I was also wondering about saturation in general. As I mentioned, you only have the option of choosing either an over/under-saturated colour space to work with, and as it's a 2D CMS rather than 3D, you can't really fix them.

DeltaC seems rather high in comparison to deltaL/H, and I'm wondering if the fact that deltaL/H are quite low in comparison to deltaC is causing the overall deltaE to be lower than it should be.

While I realise that with an oversaturated gamut, it is basically pointless to try and reduce saturation with a chroma control and that you want to use it to set luminance correctly, with an undersaturated display, is the same necessarily true?

Should I perhaps look into increasing the chroma control to strike a balance between deltaL and deltaC, rather than focusing purely on deltaL?
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post #1097 of 1936 Old 02-14-2009, 08:43 PM - Thread Starter
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Quote:
Originally Posted by andrewfee View Post

You have the choice between a Normal/Wide colour space. Wide is what you would expectcompletely oversaturated, but it's disappointing that, for a display that is capable of covering the entire Rec. 709 colour space, the contstrained "normal" gamut is undersaturated.

I believe that the Normal setting is designed to provide a SMPTE-C gamut.

Quote:
Originally Posted by andrewfee View Post

Is this a failing of the dE'94 system? Surely there must be some way of objectively calculating the optimal balance between hue/saturation errors.

You can always calculate the amount of error directly in terms of lightness, saturation, and hue, but the question of how a particular mix will affect subjective perception of color error is exactly what dE is designed to do. dE94 is my choice in this regard.

Tom Huffman
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post #1098 of 1936 Old 02-15-2009, 02:41 AM
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Quote:
Originally Posted by TomHuffman View Post

I believe that the Normal setting is designed to provide a SMPTE-C gamut.

Oh, you're right. I've just switched the target from Rec.709 to SMPTE-C in CalMAN and the colour points are much closer. (can probably get them spot-on if I make some changes to RCP)

It never even occurred to me that might have been the case. Why on earth would they constrain the wide gamut to SMPTE-C when it's a 1080p projector, and Rec.709, PAL and sRGB are all very similar, whereas SMPTE-C has a smaller gamut.

Quote:
Originally Posted by TomHuffman View Post

You can always calculate the amount of error directly in terms of lightness, saturation, and hue, but the question of how a particular mix will affect subjective perception of color error is exactly what dE is designed to do. dE94 is my choice in this regard.

I realise that's what it's supposed to do. I have no problems adjusting a 3D CMS, or a 1D CMS, as you either have total control, or know what your limitations are.

With this 2D CMS (first one I've really used I think) the chroma adjustments are easy to get right, but changing hue also has an effect on saturation/luminance.

If I'm adjusting chroma to keep luminance correct while making adjustments, saturation/hue shift in accuracy almost identically.

These aren't the real numbers (I'd have to fire up the projector and take more measurements for that) but if I keep dL around 0, I can go from having dC and dH both ≈7.5, or I can have dC at 16 and dH at 0, or dC at 0 and dH at 16 and they're all giving me a result of ≈3 dE'94 overall.


The best compromise seemed to be what I posted abovehaving dC 8.6 and dH 7.1 as it was as saturated as I could get while still being within the Rec.709 gamut.

I just wondered if there was a more objective way to decide what the best compromise is, as dE'94 isn't really helping.
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post #1099 of 1936 Old 02-15-2009, 10:36 AM
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Thank you thank you thank you thank you!
This has been a life saver!
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post #1100 of 1936 Old 02-17-2009, 07:09 AM
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In a post in the PN50A550 thread in the plasma forum, I was discussing working with the CMS. I got a reply from Doug Blackburn, a calibrator who frequents that forum.

The gist of it is that in his opinion, inexpensive filter based meters, such as the i1 display2/LT, are not accurate enough for working with a CMS.

This is pretty much in direct opposition to the guide at the beginning of this thread as well the dummies guide that suggest using these meters.

Thoughts and opinions?


http://www.avsforum.com/avs-vb/showt...11420&page=154

posts 4596 and 4606 in particular
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post #1101 of 1936 Old 02-17-2009, 07:15 AM
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As I see it, you have three options. I have listed them below in terms of increasing cost/accuracy.

1. Trust your eyeballs.
2. Use a tri-stimulus meter.
3. Use a spectroradiometer.

If you have a Display2/LT meter at your disposal your results are pretty much always going to be better than eyeballing it. Will they be perfect? Probably not but the point is that they will be better.
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post #1102 of 1936 Old 02-17-2009, 07:20 AM
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Quote:
Originally Posted by jvincent View Post

increasing cost/accuracy.

1. Trust your eyeballs.
2. Use a tri-stimulus meter.
3. Use a spectroradiometer.

for CMS work you're probably right, but, for accurate grayscale, a good tristim can beat the low-end spectros, which don't do well at low light levels... for instance the i1d2 or c5 vs i1pro...

-Greg
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post #1103 of 1936 Old 02-17-2009, 08:50 AM - Thread Starter
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Quote:
Originally Posted by Cristo View Post

The gist of it is that in his opinion, inexpensive filter based meters, such as the i1 display2/LT, are not accurate enough for working with a CMS.

First, binary statements about being accurate enough or not accurate enough are not helpful unless you know the assumed range of acceptable tolerances. Specific accuracy claims should always be accompanied by reference to a known standard, named display, and an objective metric (such as dE).

Second, the primary/secondary color accuracy of most displays is quite poor (CIE94 in the 5-11 range). Thus, using even inexpensive probes like the D2 will improve the accuracy enormously by getting that down to the CIE94 1.5-3.0 range.

Third, some displays have a preset that offers very good color accuracy (the Samsung Movie mode is a good example). In these cases the increased accuracy available through a CMS is relatively small. To reliably get that you probably would need a more expensive probe. All of the low hanging fruit has already been picked.

Fourth, you really can't say anything global about the the accuracy of inexpensive meters, such as the D2. For example, it seems very accurate for red, magenta, and blue and less accurate for white, yellow, green and cyan. But even for the colors where its performance is less precise, calibration with it can offer a profound improvement over the uncalibrated state because the inherent inaccuracies of the meter are dwarfed by the much, much larger inaccuracies of the display.

Tom Huffman
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post #1104 of 1936 Old 02-17-2009, 08:58 AM
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Quote:
Originally Posted by TomHuffman View Post

First, binary statements about being accurate enough or not accurate enough are not helpful unless you know the assumed range of acceptable tolerances. Specific accuracy claims should always be accompanied by reference to a known standard, named display, and an objective metric (such as dE).

Second, the primary/secondary color accuracy of most displays is quite poor (CIE94 in the 5-11 range). Thus, using even inexpensive probes like the D2 will improve the accuracy enormously by getting that down to the CIE94 1.5-3.0 range.

Third, some displays have a preset that offers very good color accuracy (the Samsung Movie mode is a good example). In these cases the increased accuracy available through a CMS is relatively small. To reliably get that you probably would need a more expensive probe. All of the low hanging fruit has already been picked.

Fourth, you really can't say anything global about the the accuracy of inexpensive meters, such as the D2. For example, it seems very accurate for red, magenta, and blue and less accurate for white, yellow, green and cyan. But even for the colors where its performance is less precise, calibration with it can offer a profound improvement over the uncalibrated state because the inherent inaccuracies of the meter are dwarfed by the much, much larger inaccuracies of the display.

Very well said. Especially the fourth point! I've used my EyeOne DisplayLT to calibrate several plasmas, rear projection CRTs, and LCDs and the results are far better than anything I was able to achieve by eye with color filters, Kodak gray cards and 6500K light sources, etc. The colorimeter eliminates all the guesswork.
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post #1105 of 1936 Old 02-17-2009, 09:12 AM
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Originally Posted by TomHuffman View Post

First, binary statements about being accurate enough or not accurate enough are not helpful unless you know the assumed range of acceptable tolerances. Specific accuracy claims should always be accompanied by reference to a known standard, named display, and an objective metric (such as dE).

Second, the primary/secondary color accuracy of most displays is quite poor (CIE94 in the 5-11 range). Thus, using even inexpensive probes like the D2 will improve the accuracy enormously by getting that down to the CIE94 1.5-3.0 range.

Third, some displays have a preset that offers very good color accuracy (the Samsung Movie mode is a good example). In these cases the increased accuracy available through a CMS is relatively small. To reliably get that you probably would need a more expensive probe. All of the low hanging fruit has already been picked.

Fourth, you really can't say anything global about the the accuracy of inexpensive meters, such as the D2. For example, it seems very accurate for red, magenta, and blue and less accurate for white, yellow, green and cyan. But even for the colors where its performance is less precise, calibration with it can offer a profound improvement over the uncalibrated state because the inherent inaccuracies of the meter are dwarfed by the much, much larger inaccuracies of the display.


Thanks for the reply. No doubt that global statements about accuracy can be misleading.

I've got an i1 display LT, HCFR and a Samsung PN50A550.

The source of my confusion is whether or not making adjustments in the CMS is actually improving the colors, or, given that this meter is about the cheapest thing out there and perhaps ill-suited to the task, actually making them worse.

If the colors are farther from 709 when I am done (even though my meter is saying they are closer), then obviously I should just leave it in Auto color space!

So my usage of "accurate enough" means able to make an improvement as opposed to worsening the situation by introducing errors. My concern after reading Doug's posts was that I might be doing just that, and would be better off leaving it in Auto mode (of course all of this assumes I have done the procedures correctly.)

Your specific mention of Samsung movie mode leads to me to believe I am probably already close to as good as it is going to get. I'd like to think I made it better, but I guess there is no way for me to know.
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post #1106 of 1936 Old 02-17-2009, 01:17 PM
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Tom, I understand Rec709 is the leading standard for film/cinema but what is used for tv/video, say a football game or a golf tournament shot with HD cameras? Is this an area where an extended color gamut is used or is it still Rec709?

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post #1107 of 1936 Old 02-17-2009, 03:01 PM - Thread Starter
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Originally Posted by Trackman View Post

Tom, I understand Rec709 is the leading standard for film/cinema but what is used for tv/video, say a football game or a golf tournament shot with HD cameras? Is this an area where an extended color gamut is used or is it still Rec709?

Extended color gamut isn't used anywhere I know of other than Digital Cinema. Broadcast TV is a mix of Rec. 709 and SMPTE-C.

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post #1108 of 1936 Old 02-17-2009, 04:53 PM
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Originally Posted by Cristo View Post

Thanks for the reply. No doubt that global statements about accuracy can be misleading.

I've got an i1 display LT, HCFR and a Samsung PN50A550.

The source of my confusion is whether or not making adjustments in the CMS is actually improving the colors, or, given that this meter is about the cheapest thing out there and perhaps ill-suited to the task, actually making them worse.

If the colors are farther from 709 when I am done (even though my meter is saying they are closer), then obviously I should just leave it in Auto color space!

So my usage of "accurate enough" means able to make an improvement as opposed to worsening the situation by introducing errors. My concern after reading Doug's posts was that I might be doing just that, and would be better off leaving it in Auto mode (of course all of this assumes I have done the procedures correctly.)

Your specific mention of Samsung movie mode leads to me to believe I am probably already close to as good as it is going to get. I'd like to think I made it better, but I guess there is no way for me to know.

I think what Tom is trying to point out (probably the best explanation I have seen TBH) that if the TV is already within 2% of accurate/calibrated out of the box in it's movie mode on a given color reading and you use a $150 meter (i1 D2) that reads/reports within about 2% accuracy of an actual color, you were already close enough and that meter is not accurate enough to go the extra 1% if you were trying to get razor sharp accuracy. Sooo.... Anything less than something costing 10 times more, you can perhaps play with the software and benchmark your TV's performance to give you that warm fuzzy feeling. Like you said, adjustments made based on that meter's readings could just as easily take you further away in the other direction. It's not that the meter is a bad meter but that that particular set is just that accurate usually. Most other sets are not. Especially Projectors. That is what the guide is aimed at.

For people that DONT have a Sumsung Plasma and have issues in performance, the D2 can take them closer to correct. Anyone wanting that last 1% need to spend the kind of money it takes to get that 1%.

Anyway, D2 Performance specs...

Dynamic range Black point: 0.05 cd/m2
White point: up to 1,000 cd/m2
Accuracy (LCD) Luminance: Y: typical +/- 2%
Chroma x,y: typical +/- 0.006
Accuracy (CRT) Luminance: Y: typical +/- 2%
Chroma x,y: typical +/- 0.004
Repeatability Luminance: Y: typical +/- 1%
Chroma x,y: typical +/- 0.002
Color temperature CCT (correlated color temperature)
range: typical 4000K to 120000K
accuracy: typical +/- 250K


Measurement conditions
The above are specifications of the Eye-One Display where:

Sensor is housed in CL skins with proper adapter attached for measurement
Accuracy values are given relative to the NIST-certified reference at manufacturer
Repeatability measurements are stated for same-sensor/no-dismount situation
All measurements are dark current corrected
Room temperature of 20 degrees C, +/- 5 degrees
CRT display is set to white of D50 (x.346, y.359) in a darkened room, luminance is set to 80 cd/m2 or greater at full white, an EBU or P22 phosphor set
LCD display is set to white of D65 (x.313, y.329) in a darkened room, luminance is set to 120 cd/m2 or greater at full white

Panasonic 42" Plasma TH42-PZ85U
Panasonic Blueray Player DMP-BD35
Sony 5.1 Home Theater DAV-HDX475 (wish it was Panasonic but it's ok)
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post #1109 of 1936 Old 02-17-2009, 05:56 PM
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Quote:
Originally Posted by Cristo View Post

Thanks for the reply. No doubt that global statements about accuracy can be misleading.

I've got an i1 display LT, HCFR and a Samsung PN50A550.

The source of my confusion is whether or not making adjustments in the CMS is actually improving the colors, or, given that this meter is about the cheapest thing out there and perhaps ill-suited to the task, actually making them worse.

If the colors are farther from 709 when I am done (even though my meter is saying they are closer), then obviously I should just leave it in Auto color space!

So my usage of "accurate enough" means able to make an improvement as opposed to worsening the situation by introducing errors. My concern after reading Doug's posts was that I might be doing just that, and would be better off leaving it in Auto mode (of course all of this assumes I have done the procedures correctly.)

Your specific mention of Samsung movie mode leads to me to believe I am probably already close to as good as it is going to get. I'd like to think I made it better, but I guess there is no way for me to know.

I feel you Cristo.
I have the Samsung Ln46A630 and recently tried calibrating it with the EyeOne, HCFR software, and the AVSHD dvd and followed Tom's instructions as well as those from this other forum thread http://www.curtpalme.com/forum/viewtopic.php?t=10457

My grayscale and gamma reported being way off but the colors were fairly close (relatively speaking). Perceptually I feel like I was able to make a decent improvement. But being a perfectionist, I still want to hone my calibrating skills to get the CIE chart and dE as near perfect as possible.
But I do like how the "Auto" color setting is suppose to adjust the colorspace depending on the source. So I use that for cable tv watching since I can't seem to find test patterns on comcast.

Tom,

A side question for you. Should I be calibrating from the service menu or stick with the user menu? I don't mind going into the sm and messing with things. I have a cheaper LN32A550 to practice on if you think I'll make irreparable damage. I assume the adjustments in the sm have a wider range ie. more gamma, and wider RGBCMY options as it seems there are times I'd like to further adjust the three colors within a color but cannot go below 0 or higher than 100.
Any help is greatly appreciated,
Brad
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post #1110 of 1936 Old 02-20-2009, 03:24 PM
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Hey Tom,

Great thread. Thank you tons for all the help.
In the Samsung calibrating thread we have a question about setting gray scale. Should gray scale be set with the color control set to zero? Thus reducing the image to black and white. Or should it be left at the default setting (for us = 50)?

Many thanks,
Brad
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