new i1pro 2 spectrophotometer - Page 4 - AVS Forum
Forum Jump: 
Reply
 
Thread Tools
post #91 of 149 Old 05-11-2012, 04:57 AM
AVS Special Member
 
PlasmaPZ80U's Avatar
 
Join Date: Feb 2009
Posts: 7,195
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 88 Post(s)
Liked: 198
Quote:
Originally Posted by ConnecTEDDD View Post

Profiling is designed for grayscale as a colorimeter is much quicker and more accurate at low light levels.

You need a new profile after any gamut change because when you are doing meter profiling, you are teaching the colorimeter where the primaries are. If you move the primaries doing CMS then the profile is off.

That's why both instruments are required, spectro for the colour gamut and then a profiled colorimeter for greyscale.

if the xy of the primaries is left alone and only the brightness is adjusted (plus hues of secondaries), will the profile still work correctly? such as with setting color/tint?

and how much change must be made to the primaries for the profile to no longer work properly?


To view links or images in signatures your post count must be 0 or greater. You currently have 0 posts.



To view links or images in signatures your post count must be 0 or greater. You currently have 0 posts.



To view links or images in signatures your post count must be 0 or greater. You currently have 0 posts.
PlasmaPZ80U is offline  
Sponsored Links
Advertisement
 
post #92 of 149 Old 05-11-2012, 07:47 AM
AVS Special Member
 
airscapes's Avatar
 
Join Date: Dec 2008
Location: Philadelphia
Posts: 4,628
Mentioned: 1 Post(s)
Tagged: 0 Thread(s)
Quoted: 55 Post(s)
Liked: 111
Quote:
Originally Posted by ConnecTEDDD View Post

Profiling is designed for grayscale as a colorimeter is much quicker and more accurate at low light levels.

You need a new profile after any gamut change because when you are doing meter profiling, you are teaching the colorimeter where the primaries are. If you move the primaries doing CMS then the profile is off.

That's why both instruments are required, spectro for the colour gamut and then a profiled colorimeter for greyscale.

Interesting and somewhat disappointing if this is true (I expect it is not) since it is the first time I have read this anywhere. I have talked at length with several pro calibrators about profiling and was never told that the profile needs to be redone after CMS is changed.

The profile is related to the spectral properties of the lamp source and has nothing to do with any of the calibration controls It is performed BEFORE any calibrations is done.
looking at the profile, the software is reading WRGB with each meter and creating an table of the deltas between the 2 devices. If all was equal in the hardware the profile would be all 00000s. Then this table of deltas is applied to the profiled meters readings of whatever it reads for all readings. Moving a primary color from one spot to another does not change the difference in how the 2 meters read that color, so please explain the science behind your statement. "You need a new profile after any gamut change"
I am not trying to start trouble, I just do not believe this is accurate and do not want to proliferate false data on a forum where it will remain for a long time. If I am wrong so be it, but please prove me so with documents from specrcal/chromapure or other respected facility.
Thanks!

Doug

To view links or images in signatures your post count must be 0 or greater. You currently have 0 posts.

 

airscapes is online now  
post #93 of 149 Old 05-11-2012, 08:34 AM
AVS Special Member
 
PlasmaPZ80U's Avatar
 
Join Date: Feb 2009
Posts: 7,195
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 88 Post(s)
Liked: 198
Quote:
Originally Posted by airscapes View Post

Interesting and somewhat disappointing if this is true (I expect it is not) since it is the first time I have read this anywhere. I have talked at length with several pro calibrators about profiling and was never told that the profile needs to be redone after CMS is changed.

The profile is related to the spectral properties of the lamp source and has nothing to do with any of the calibration controls It is performed BEFORE any calibrations is done.
looking at the profile, the software is reading WRGB with each meter and creating an table of the deltas between the 2 devices. If all was equal in the hardware the profile would be all 00000s. Then this table of deltas is applied to the profiled meters readings of whatever it reads for all readings. Moving a primary color from one spot to another does not change the difference in how the 2 meters read that color, so please explain the science behind your statement. "You need a new profile after any gamut change"
I am not trying to start trouble, I just do not believe this is accurate and do not want to proliferate false data on a forum where it will remain for a long time. If I am wrong so be it, but please prove me so with documents from specrcal/chromapure or other respected facility.
Thanks!

I think you're probably right since I remember reading somewhere that the CMS doesn't change the physical (native) primaries of the display, which are fixed. I think statements like gamut work requires a spectro (as opposed to a profiled colorimeter) falls in the same category of myths as you can't do gamut work with a colorimeter period (regardless of profiles). However, I'm not 100% sure.

I will say the following, though. The errors the C6's tables leave behind on my LG are mostly in grayscale, not gamut (versus a spectro directly or the profile created for it). Therefore, it is more accurate with gamut measurements than grayscale ones.


To view links or images in signatures your post count must be 0 or greater. You currently have 0 posts.



To view links or images in signatures your post count must be 0 or greater. You currently have 0 posts.



To view links or images in signatures your post count must be 0 or greater. You currently have 0 posts.
PlasmaPZ80U is offline  
post #94 of 149 Old 05-11-2012, 08:35 AM
AVS Special Member
 
zoyd's Avatar
 
Join Date: Sep 2006
Location: Planet Dog
Posts: 4,499
Mentioned: 18 Post(s)
Tagged: 0 Thread(s)
Quoted: 111 Post(s)
Liked: 321
Quote:
Originally Posted by ConnecTEDDD View Post

Profiling is designed for grayscale as a colorimeter is much quicker and more accurate at low light levels.

You need a new profile after any gamut change because when you are doing meter profiling, you are teaching the colorimeter where the primaries are. If you move the primaries doing CMS then the profile is off.

That's why both instruments are required, spectro for the colour gamut and then a profiled colorimeter for greyscale.

This is not true, a profiled colorimeter works fine for the entire gamut. Think about it, white and grays are just colors, why would a profiled colorimeter work there and not elsewhere? Also, once profiled it does not have to be profiled again unless you think it has drifted or you use it on another display with different spectral characteristics. To show you this, here is the measurement of RGBW deltax and deltay between an i1pro 2 and an i1D3 on my display(plasma) with and without the CMS engaged, there is no difference within the precision of the two probes. This measurement was done using a single profile.

Primary locations
R G B W
CMS On 0.6476 0.2945 0.1507 0.3114
0.3292 0.6040 0.0574 0.3276
CMS Off 0.6594 0.2746 0.1501 0.3115
0.3322 0.6196 0.0568 0.3277

Measurement deltas (D3-i1pro 2)
CMS On R G B W
deltax -0.0034 0.0008 0.0003 0.0005
deltay -0.0001 -0.0015 0.0003 0.0000
CMS Off (Native color)
deltax -0.0019 0.0017 0.0007 0.0009
deltay -0.0002 -0.0028 0.0007 0.0002

-----

To view links or images in signatures your post count must be 0 or greater. You currently have 0 posts.


To view links or images in signatures your post count must be 0 or greater. You currently have 0 posts.


To view links or images in signatures your post count must be 0 or greater. You currently have 0 posts.


To view links or images in signatures your post count must be 0 or greater. You currently have 0 posts.
zoyd is online now  
post #95 of 149 Old 05-11-2012, 08:43 AM
AVS Special Member
 
ConnecTEDDD's Avatar
 
Join Date: Sep 2010
Location: Athens, Greece
Posts: 2,300
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 93 Post(s)
Liked: 469
Quote:
Originally Posted by airscapes View Post

If I am wrong so be it, but please prove me so with documents from specrcal/chromapure or other respected facility.
Thanks!

Re: two meter calibrations?
by derekjsmith » Tue Dec 08, 2009 8:14 pm

The reason you need to profile after any CMS work is becasue when profiling you are teaching the meter where the primarys are ifyou move them then the profile is off.

Derek Smith CTO/Founder

ISF Certified Calibrator
THX Certified Professional


To view links or images in signatures your post count must be 0 or greater. You currently have 0 posts.

S/W: LightSpace CMS, SpaceMan ICC, SpaceMatch DCM, CalMAN 5, CalMAN RGB, ChromaPure, CalPC, ControlCAL
Meters: JETI Specbos 1211, Klein K-10A, i1PRO2, i1PRO, SpectraCAL C6, i1D3, C5
ConnecTEDDD is offline  
post #96 of 149 Old 05-11-2012, 08:47 AM
AVS Special Member
 
PlasmaPZ80U's Avatar
 
Join Date: Feb 2009
Posts: 7,195
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 88 Post(s)
Liked: 198
Quote:
Originally Posted by zoyd View Post

This is not true, a profiled colorimeter works fine for the entire gamut. Think about it, white and grays are just colors, why would a profiled colorimeter work there and not elsewhere? Also, once profiled it does not have to be profiled again unless you think it has drifted or you use it on another display with different spectral characteristics. To show you this, here is the measurement of RGBW deltax and deltay between an i1pro 2 and an i1D3 on my display(plasma) with and without the CMS engaged, there is no difference within the precision of the two probes. This measurement was done using a single profile.

Primary locations
R G B W
CMS On 0.6476 0.2945 0.1507 0.3114
0.3292 0.6040 0.0574 0.3276
CMS Off 0.6594 0.2746 0.1501 0.3115
0.3322 0.6196 0.0568 0.3277

Measurement deltas (D3-i1pro 2)
CMS On R G B W
deltax -0.0034 0.0008 0.0003 0.0005
deltay -0.0001 -0.0015 0.0003 0.0000
CMS Off (Native color)
deltax -0.0019 0.0017 0.0007 0.0009
deltay -0.0002 -0.0028 0.0007 0.0002

The profile should last as long as the colorimeter retains its accuracy from the date the profile was created. So, meter drift is the only thing that can render a profile ineffective on the display it was created on. Display drift is not a relevant factor. Of course, the profile can only be used on the display it was created on.


To view links or images in signatures your post count must be 0 or greater. You currently have 0 posts.



To view links or images in signatures your post count must be 0 or greater. You currently have 0 posts.



To view links or images in signatures your post count must be 0 or greater. You currently have 0 posts.
PlasmaPZ80U is offline  
post #97 of 149 Old 05-11-2012, 08:50 AM
AVS Special Member
 
airscapes's Avatar
 
Join Date: Dec 2008
Location: Philadelphia
Posts: 4,628
Mentioned: 1 Post(s)
Tagged: 0 Thread(s)
Quoted: 55 Post(s)
Liked: 111
Quote:
Originally Posted by ConnecTEDDD View Post

Re: two meter calibrations?
by derekjsmith » Tue Dec 08, 2009 8:14 pm

The reason you need to profile after any CMS work is becasue when profiling you are teaching the meter where the primarys are ifyou move them then the profile is off.

Derek Smith CTO/Founder

ISF Certified Calibrator
THX Certified Professional

Scroll down the thread a little..
Joel's response..
Re: two meter calibrations?

Postby Joel Barsotti » Sun Jan 02, 2011 6:53 pm
If the TV is properly warmed up, there is no reason to re-profile during a calibration.

A four color matrix profile is effected by the color of the color filters/phosphors and the spectral output of the lamp (if the display uses one).

Once that profile is created for the display it will remain accurate far beyond duration of the calibration.

There may be an argument for using a profiled chroma 5 for gray scale, where the chroma5 is the inherently more accurate (and faster) instrument for the low end readings, and using the i1 Pro for CMS, where it is the inherently more accurate instrument.
SpectraCal Developer

Please NOTE when Derek posted and Joel Posted.. was a few years apart..

Doug

To view links or images in signatures your post count must be 0 or greater. You currently have 0 posts.

 

airscapes is online now  
post #98 of 149 Old 05-11-2012, 08:52 AM
AVS Special Member
 
PlasmaPZ80U's Avatar
 
Join Date: Feb 2009
Posts: 7,195
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 88 Post(s)
Liked: 198
Quote:
Originally Posted by ConnecTEDDD View Post

Re: two meter calibrations?
by derekjsmith » Tue Dec 08, 2009 8:14 pm

The reason you need to profile after any CMS work is becasue when profiling you are teaching the meter where the primarys are ifyou move them then the profile is off.

Derek Smith CTO/Founder

ISF Certified Calibrator
THX Certified Professional

Yes, but Sotti states the following:

"If the TV is properly warmed up, there is no reason to re-profile during a calibration.

A four color matrix profile is effected by the color of the color filters/phosphors and the spectral output of the lamp (if the display uses one).

Once that profile is created for the display it will remain accurate far beyond duration of the calibration.

There may be an argument for using a profiled chroma 5 for gray scale, where the chroma5 is the inherently more accurate (and faster) instrument for the low end readings, and using the i1 Pro for CMS, where it is the inherently more accurate instrument."


To view links or images in signatures your post count must be 0 or greater. You currently have 0 posts.



To view links or images in signatures your post count must be 0 or greater. You currently have 0 posts.



To view links or images in signatures your post count must be 0 or greater. You currently have 0 posts.
PlasmaPZ80U is offline  
post #99 of 149 Old 05-11-2012, 08:54 AM
AVS Special Member
 
PlasmaPZ80U's Avatar
 
Join Date: Feb 2009
Posts: 7,195
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 88 Post(s)
Liked: 198
Quote:
Originally Posted by airscapes View Post

Scroll down the thread a little..
Joel's response..
Re: two meter calibrations?

Postby Joel Barsotti » Sun Jan 02, 2011 6:53 pm
If the TV is properly warmed up, there is no reason to re-profile during a calibration.

A four color matrix profile is effected by the color of the color filters/phosphors and the spectral output of the lamp (if the display uses one).

Once that profile is created for the display it will remain accurate far beyond duration of the calibration.

There may be an argument for using a profiled chroma 5 for gray scale, where the chroma5 is the inherently more accurate (and faster) instrument for the low end readings, and using the i1 Pro for CMS, where it is the inherently more accurate instrument.
SpectraCal Developer

Please NOTE when Derek posted and Joel Posted.. was a few years apart..

oops, looks like I posted the same thing


To view links or images in signatures your post count must be 0 or greater. You currently have 0 posts.



To view links or images in signatures your post count must be 0 or greater. You currently have 0 posts.



To view links or images in signatures your post count must be 0 or greater. You currently have 0 posts.
PlasmaPZ80U is offline  
post #100 of 149 Old 05-11-2012, 08:55 AM
AVS Special Member
 
Chronoptimist's Avatar
 
Join Date: Sep 2009
Posts: 2,578
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 1 Post(s)
Liked: 223
So assuming your i1Pro has been looked after and is still passing certification, is there any reason to upgrade to the new model?

It appears that the biggest changes here are:

1) Better temperature stabilitya non-issue if you allow time for the meter to acclimate to the room before starting calibration, and use it as a non-contact meter. (I never use it on a display now)

2) Better low-light handling due to adaptive integration time... something that has been implemented in CalMAN since v3?

3) Better stability so that the meter no longer needs frequent dark offset measurements. If you are using the meter in a non-contact fashion, this takes all of two seconds to either hold the baseplate up to the meter and press the button on the meter to take a dark reading (at least that's how I have it configured in CalMAN) or even easier if you have the beamer attachment, where you just flick the window closed.


It seems like the biggest change here is for print work with the integration of a UV LED, rather than there being much for display calibration. (though I suppose it will fare better in other display profiling packages that take more than 10 minutes to complete, and don't take new dark offset readings)

Actually, now that I think of it, has the i1 Beamer been discontinued as well now? Perhaps I should finally get a hold of one. I've been meaning to for a long time, but kept putting it off due to the price. (seems rather bulky too, but nothing else has a window for the dark offset readings)
Chronoptimist is offline  
post #101 of 149 Old 05-11-2012, 08:59 AM
AVS Special Member
 
PlasmaPZ80U's Avatar
 
Join Date: Feb 2009
Posts: 7,195
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 88 Post(s)
Liked: 198
Quote:
Originally Posted by Chronoptimist View Post

So assuming your i1Pro has been looked after and is still passing certification, is there any reason to upgrade to the new model?

It appears that the biggest changes here are:

1) Better temperature stabilitya non-issue if you allow time for the meter to acclimate to the room before starting calibration, and use it as a non-contact meter. (I never use it on a display now)

2) Better low-light handling due to adaptive integration time... something that has been implemented in CalMAN since v3?

3) Better stability so that the meter no longer needs frequent dark offset measurements. If you are using the meter in a non-contact fashion, this takes all of two seconds to either hold the baseplate up to the meter and press the button on the meter to take a dark reading (at least that's how I have it configured in CalMAN) or even easier if you have the beamer attachment, where you just flick the window closed.


It seems like the biggest change here is for print work with the integration of a UV LED, rather than there being much for display calibration. (though I suppose it will fare better in other display profiling packages that take more than 10 minutes to complete, and don't take new dark offset readings)

Actually, now that I think of it, has the i1 Beamer been discontinued as well now? Perhaps I should finally get a hold of one. I've been meaning to for a long time, but kept putting it off due to the price. (seems rather bulky too, but nothing else has a window for the dark offset readings)

I'd say you're right about those points, at least that's how I see it. Regarding #1, can the i1Pro be used in contact mode without compromising the accuracy of its readings (for either xy or Y)?


To view links or images in signatures your post count must be 0 or greater. You currently have 0 posts.



To view links or images in signatures your post count must be 0 or greater. You currently have 0 posts.



To view links or images in signatures your post count must be 0 or greater. You currently have 0 posts.
PlasmaPZ80U is offline  
post #102 of 149 Old 05-11-2012, 09:50 AM
AVS Special Member
 
sotti's Avatar
 
Join Date: Aug 2004
Location: Seattle, WA
Posts: 6,621
Mentioned: 2 Post(s)
Tagged: 0 Thread(s)
Quoted: 28 Post(s)
Liked: 167
C6 profiled to an i1 Pro on a Dell u2410
sRGB
X 1.00252818079185 0.0150016519024727 -0.00217041386263861
Y 0.0129950060226554 0.996120171401034 0.00598637047781003
Z 0.016526894401621 -0.000414306321654179 0.964323850594334

Adobe RGB
X 0.993650649329514 0.0227039250738613 -0.00173760538076273
Y 0.0072376727107768 1.00042893345707 0.00656957859772778
Z 0.0068137782308848 0.00822748741473489 0.964466161431914

sRGB Again (profile to profile variance)
X 0.991231215012878 0.0198381428333259 -0.000874258265253003
Y 0.00513239371941099 0.998315400076571 0.00767244990494143
Z 0.00686278375836658 0.0040739858499963 0.961909822252622

So basically these matrix work like scalers so if they are different my 0.001 that's only a 1/10th of 1 percent difference.

I'm going to follow up with some screen shots to show how while the intensities may change the shape doesn't which is why the profiles are very similiar.

Joel Barsotti
SpectraCal
CalMAN Lead Developer
sotti is offline  
post #103 of 149 Old 05-11-2012, 10:53 AM
AVS Special Member
 
sotti's Avatar
 
Join Date: Aug 2004
Location: Seattle, WA
Posts: 6,621
Mentioned: 2 Post(s)
Tagged: 0 Thread(s)
Quoted: 28 Post(s)
Liked: 167
Here is what sRGB looks like
LL
LL
LL
LL
LL

Joel Barsotti
SpectraCal
CalMAN Lead Developer
sotti is offline  
post #104 of 149 Old 05-11-2012, 10:54 AM
AVS Special Member
 
sotti's Avatar
 
Join Date: Aug 2004
Location: Seattle, WA
Posts: 6,621
Mentioned: 2 Post(s)
Tagged: 0 Thread(s)
Quoted: 28 Post(s)
Liked: 167
Here is what Adobe RGB Looks like
LL
LL
LL
LL
LL

Joel Barsotti
SpectraCal
CalMAN Lead Developer
sotti is offline  
post #105 of 149 Old 05-11-2012, 10:58 AM
AVS Special Member
 
sotti's Avatar
 
Join Date: Aug 2004
Location: Seattle, WA
Posts: 6,621
Mentioned: 2 Post(s)
Tagged: 0 Thread(s)
Quoted: 28 Post(s)
Liked: 167
So while for absolute accuracy you'd profile again, really the differences are VERY small.

The reason is the shape of the spectrum doesn't change, so if Z is off a little bit it will be off by nearly the same percentage regardless of the amount of blue in the field.

The differences are almost assuredly from the non-linearity involved in the display. Meaning you'd see equally sized if not larger differences if you profile at 50% or 100% instead of 75% with the same gamut.

Joel Barsotti
SpectraCal
CalMAN Lead Developer
sotti is offline  
post #106 of 149 Old 05-11-2012, 11:04 AM
AVS Special Member
 
PlasmaPZ80U's Avatar
 
Join Date: Feb 2009
Posts: 7,195
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 88 Post(s)
Liked: 198
Quote:
Originally Posted by sotti View Post

So while for absolute accuracy you'd profile again, really the differences are VERY small.

would in then be correct to say those differences wouldn't be visible with regular program material?


To view links or images in signatures your post count must be 0 or greater. You currently have 0 posts.



To view links or images in signatures your post count must be 0 or greater. You currently have 0 posts.



To view links or images in signatures your post count must be 0 or greater. You currently have 0 posts.
PlasmaPZ80U is offline  
post #107 of 149 Old 05-11-2012, 11:04 AM
Advanced Member
 
djams's Avatar
 
Join Date: Nov 2010
Location: Plano, TX
Posts: 724
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
Liked: 10
Quote:
Originally Posted by airscapes View Post


Please explain what we are looking at.

It looks like a 3x3 matrix that describes the transformation between 2 coordinate systems.

Edit: after looking again, it looks more like its just a scaling matrix. Xred*Xredmatrix= profiled Xred, etc.
djams is offline  
post #108 of 149 Old 05-11-2012, 11:23 AM
AVS Special Member
 
sotti's Avatar
 
Join Date: Aug 2004
Location: Seattle, WA
Posts: 6,621
Mentioned: 2 Post(s)
Tagged: 0 Thread(s)
Quoted: 28 Post(s)
Liked: 167
Quote:
Originally Posted by PlasmaPZ80U View Post

would in then be correct to say those differences wouldn't be visible with regular program material?

The differences are probably just above reading to reading error.

the difference between the sRGB and Adobe RGB would shift D65 at 100cd/m
from
0.312727, 0.329023, 100
to:
0.312687, 0.329064, 100.05

which is a dE 94 shift of 0.04

Joel Barsotti
SpectraCal
CalMAN Lead Developer
sotti is offline  
post #109 of 149 Old 05-11-2012, 12:18 PM
AVS Special Member
 
airscapes's Avatar
 
Join Date: Dec 2008
Location: Philadelphia
Posts: 4,628
Mentioned: 1 Post(s)
Tagged: 0 Thread(s)
Quoted: 55 Post(s)
Liked: 111
@ConnecTEDDD, I stand corrected and happy about it! My understanding of the profile was obviously incorrect. I should have made a few calls to verify what was in my head was accurate before posting.

Sotti, as a followup, would you say these 2 statements would be the take-away from this discussion for those of us with Colorimetes and a spectro?

1. If you have a Spectro, there is no reason to be using a Colorimeter to do CMS since the Spectro is more accurate (or you would not profile against it) and the patterns for CMS should be of sufficient brightness that speed is not an issue.

2. If you only have a colorimeter, and it has been profiled to your display, the difference that would occur while making minor adjusts in the CMS would not be large enough to say that the adjustments are invalid.

Thanks!

Doug

To view links or images in signatures your post count must be 0 or greater. You currently have 0 posts.

 

airscapes is online now  
post #110 of 149 Old 05-11-2012, 12:24 PM
AVS Special Member
 
PlasmaPZ80U's Avatar
 
Join Date: Feb 2009
Posts: 7,195
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 88 Post(s)
Liked: 198
Quote:
Originally Posted by airscapes View Post

@ConnecTEDDD, I stand corrected and happy about it! My understanding of the profile was obviously incorrect. I should have made a few calls to verify what was in my head was accurate before posting.

Sotti, as a followup, would you say these 2 statements would be the take-away from this discussion for those of us with Colorimetes and a spectro?

1. If you have a Spectro, there is no reason to be using a Colorimeter to do CMS since the Spectro is more accurate (or you would not profile against it) and the patterns for CMS should be of sufficient brightness that speed is not an issue.

2. If you only have a colorimeter, and it has been profiled to your display, the difference that would occur while making minor adjusts in the CMS would not be large enough to say that the adjustments are invalid.

Thanks!

Does point #1 really matter though? Couldn't you just use the profiled colorimeter for convenience reasons?

I'd say ConnecTEDDD was correct from a purely technical standpoint but you were correct from a practical standpoint. It should not matter whether you use the profiled colorimeter or spectro for gamut work, it's really just a matter of preference of the calibrator. Nothing worth worrying about.


To view links or images in signatures your post count must be 0 or greater. You currently have 0 posts.



To view links or images in signatures your post count must be 0 or greater. You currently have 0 posts.



To view links or images in signatures your post count must be 0 or greater. You currently have 0 posts.
PlasmaPZ80U is offline  
post #111 of 149 Old 05-11-2012, 12:47 PM
AVS Special Member
 
airscapes's Avatar
 
Join Date: Dec 2008
Location: Philadelphia
Posts: 4,628
Mentioned: 1 Post(s)
Tagged: 0 Thread(s)
Quoted: 55 Post(s)
Liked: 111
Quote:
Originally Posted by PlasmaPZ80U View Post

Does point #1 really matter though? Couldn't you just use the profiled colorimeter for convenience reasons?

I'd say ConnecTEDDD was correct from a purely technical standpoint but you were correct from a practical standpoint. It should not matter whether you use the profiled colorimeter or spectro for gamut work, it's really just a matter of preference of the calibrator. Nothing worth worrying about.

Maybe so, but when you step back and think about it, Isn't it all about being accurate? You have a spectro and hung it to profile, it should still be hanging or attached to the tripod and connected to the the laptop. 2 clicks of a mouse and you are using it and you know it is the more accurate of the 2 devices. Taking gray scale readings at .9fl I would not want to use the i1pro.. But adjusting a CMS, it would be the better tool for the job.

Doug

To view links or images in signatures your post count must be 0 or greater. You currently have 0 posts.

 

airscapes is online now  
post #112 of 149 Old 05-11-2012, 01:06 PM
AVS Special Member
 
sotti's Avatar
 
Join Date: Aug 2004
Location: Seattle, WA
Posts: 6,621
Mentioned: 2 Post(s)
Tagged: 0 Thread(s)
Quoted: 28 Post(s)
Liked: 167
Quote:
Originally Posted by airscapes View Post

1. If you have a Spectro, there is no reason to be using a Colorimeter to do CMS since the Spectro is more accurate (or you would not profile against it) and the patterns for CMS should be of sufficient brightness that speed is not an issue.

I wouldn't say there is no reason, the time to switch meters is something.

Quote:
Originally Posted by airscapes View Post

2. If you only have a colorimeter, and it has been profiled to your display, the difference that would occur while making minor adjusts in the CMS would not be large enough to say that the adjustments are invalid.

Deffinetly, the shape of the spectrum is the issue, not how it's balanced.

Joel Barsotti
SpectraCal
CalMAN Lead Developer
sotti is offline  
post #113 of 149 Old 05-11-2012, 01:44 PM
AVS Addicted Member
 
DaGamePimp's Avatar
 
Join Date: Jan 2001
Location: WA State
Posts: 15,522
Mentioned: 1 Post(s)
Tagged: 0 Thread(s)
Quoted: 28 Post(s)
Liked: 160
Sorry I opened that can of worms but glad I did at the same time, some great info there.

I have been using the profiled i1D3 for grayscale and the i1Pro for gamut figuring this was a logical approach since even once profiled they read very slightly different (now does it matter, IDK, but most of us here possibly suffer some degree of OCD or we would not be in here worrying about it as we spend countless hours learning and calibrating ).

Jason

My Twitch Game Stream [PS4/Xone/PC]...
To view links or images in signatures your post count must be 0 or greater. You currently have 0 posts.


To view links or images in signatures your post count must be 0 or greater. You currently have 0 posts.


To view links or images in signatures your post count must be 0 or greater. You currently have 0 posts.


To view links or images in signatures your post count must be 0 or greater. You currently have 0 posts.


To view links or images in signatures your post count must be 0 or greater. You currently have 0 posts.
DaGamePimp is online now  
post #114 of 149 Old 05-11-2012, 03:50 PM
AVS Special Member
 
PlasmaPZ80U's Avatar
 
Join Date: Feb 2009
Posts: 7,195
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 88 Post(s)
Liked: 198
Quote:
Originally Posted by sotti View Post

The differences are probably just above reading to reading error.

the difference between the sRGB and Adobe RGB would shift D65 at 100cd/m
from
0.312727, 0.329023, 100
to:
0.312687, 0.329064, 100.05

which is a dE 94 shift of 0.04

Quote:
Originally Posted by DaGamePimp View Post

Sorry I opened that can of worms but glad I did at the same time, some great info there.

I have been using the profiled i1D3 for grayscale and the i1Pro for gamut figuring this was a logical approach since even once profiled they read very slightly different (now does it matter, IDK, but most of us here possibly suffer some degree of OCD or we would not be in here worrying about it as we spend countless hours learning and calibrating ).

Jason

good point, but a dE94 shift of 0.04 is literally zero if you round it to one decimal place... even for those who pick nits, that's virtually nothing (even on paper)

I'd say there are far more important things to worry about when calibrating, such as those brought up earlier in this thread.


To view links or images in signatures your post count must be 0 or greater. You currently have 0 posts.



To view links or images in signatures your post count must be 0 or greater. You currently have 0 posts.



To view links or images in signatures your post count must be 0 or greater. You currently have 0 posts.
PlasmaPZ80U is offline  
post #115 of 149 Old 05-11-2012, 04:01 PM
AVS Special Member
 
sotti's Avatar
 
Join Date: Aug 2004
Location: Seattle, WA
Posts: 6,621
Mentioned: 2 Post(s)
Tagged: 0 Thread(s)
Quoted: 28 Post(s)
Liked: 167
Quote:
Originally Posted by PlasmaPZ80U View Post

good point, but a dE94 shift of 0.04 is literally zero if you round it to one decimal place... even for those who pick nits, that's virtually nothing (even on paper)

I'd say there are far more important things to worry about when calibrating, such as those brought up earlier in this thread.

One thing to note is that the numbers were "somewhat" repeatable. I ran the profiler several times to be sure before I posted. The matrix was definitely different from one profile to the next, the control sRGB was done on a different part of the screen.

So the difference is real, even if insignificant.

Joel Barsotti
SpectraCal
CalMAN Lead Developer
sotti is offline  
post #116 of 149 Old 05-11-2012, 04:04 PM
AVS Special Member
 
PlasmaPZ80U's Avatar
 
Join Date: Feb 2009
Posts: 7,195
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 88 Post(s)
Liked: 198
Quote:
Originally Posted by sotti View Post

One thing to note is that the numbers were "somewhat" repeatable. I ran the profiler several times to be sure before I posted. The matrix was definitely different from one profile to the next, the control sRGB was done on a different part of the screen.

So the difference is real, even if insignificant.

then wouldn't screen uniformity play a role?


To view links or images in signatures your post count must be 0 or greater. You currently have 0 posts.



To view links or images in signatures your post count must be 0 or greater. You currently have 0 posts.



To view links or images in signatures your post count must be 0 or greater. You currently have 0 posts.
PlasmaPZ80U is offline  
post #117 of 149 Old 05-11-2012, 04:15 PM
AVS Special Member
 
sotti's Avatar
 
Join Date: Aug 2004
Location: Seattle, WA
Posts: 6,621
Mentioned: 2 Post(s)
Tagged: 0 Thread(s)
Quoted: 28 Post(s)
Liked: 167
Quote:
Originally Posted by PlasmaPZ80U View Post

then wouldn't screen uniformity play a role?

It does and it did. Repeated runs in the same locations showed less variance, but still varied and even profiling in a different location is almost as different as switching between wide gamut and sRGB.

Joel Barsotti
SpectraCal
CalMAN Lead Developer
sotti is offline  
post #118 of 149 Old 05-11-2012, 04:21 PM
AVS Addicted Member
 
DaGamePimp's Avatar
 
Join Date: Jan 2001
Location: WA State
Posts: 15,522
Mentioned: 1 Post(s)
Tagged: 0 Thread(s)
Quoted: 28 Post(s)
Liked: 160
Quote:
Originally Posted by PlasmaPZ80U View Post

I'd say there are far more important things to worry about when calibrating, such as those brought up earlier in this thread.

Hehe, that was exactly my point... yet here we are discussing it.

Jason

My Twitch Game Stream [PS4/Xone/PC]...
To view links or images in signatures your post count must be 0 or greater. You currently have 0 posts.


To view links or images in signatures your post count must be 0 or greater. You currently have 0 posts.


To view links or images in signatures your post count must be 0 or greater. You currently have 0 posts.


To view links or images in signatures your post count must be 0 or greater. You currently have 0 posts.


To view links or images in signatures your post count must be 0 or greater. You currently have 0 posts.
DaGamePimp is online now  
post #119 of 149 Old 05-12-2012, 01:02 PM
AVS Special Member
 
PlasmaPZ80U's Avatar
 
Join Date: Feb 2009
Posts: 7,195
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 88 Post(s)
Liked: 198
One thing worth mentioning here is most gamut changes when calibrating with CMS are not as drastic as the difference between the two gamuts shown in the example Sotti provided. So if you're only changing the primaries a little bit, the difference should be much smaller. Something to thing about.


To view links or images in signatures your post count must be 0 or greater. You currently have 0 posts.



To view links or images in signatures your post count must be 0 or greater. You currently have 0 posts.



To view links or images in signatures your post count must be 0 or greater. You currently have 0 posts.
PlasmaPZ80U is offline  
post #120 of 149 Old 05-12-2012, 01:52 PM
AVS Special Member
 
zoyd's Avatar
 
Join Date: Sep 2006
Location: Planet Dog
Posts: 4,499
Mentioned: 18 Post(s)
Tagged: 0 Thread(s)
Quoted: 111 Post(s)
Liked: 321
It doesn't matter how much the primaries changes or if you want to go and measure some other color, the profiled colorimeter will match the spectro within their respective error bars given two conditions:

1. The spectral shape of the 3 primaries does not change.
2. The probes have linear response in X,Y,Z between the two luminance levels being measured.

Condition 1. is always met on the same display for plasmas because it's driven by the physics of phosphorescence which is extremely stable. I can't comment on other display technologies.

Condition 2. is driven by the inherent linearity of the sensor/amplifier system within each probe including sensitivity drift. I haven't looked up the exact specs on the D3 and i1pro 2 but this is typically 0.1%-0.2% until you get to the extremes of the dynamic range.

So if you want to do color work with the profiled colorimeter and are worried about accuracy, reprofile when you have a large change in luminance not chromaticity. This is also why it's better to profile at 75% stimulus (~50% luminance) and not 100%.

-----

To view links or images in signatures your post count must be 0 or greater. You currently have 0 posts.


To view links or images in signatures your post count must be 0 or greater. You currently have 0 posts.


To view links or images in signatures your post count must be 0 or greater. You currently have 0 posts.


To view links or images in signatures your post count must be 0 or greater. You currently have 0 posts.
zoyd is online now  
Reply Display Calibration

User Tag List

Thread Tools
Show Printable Version Show Printable Version
Email this Page Email this Page


Forum Jump: 

Posting Rules  
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are Off
Pingbacks are Off
Refbacks are Off