Final answer on Color Matrix Ajustments??? at DVinfo.net

Cal Bickford · January 11th, 2008, 09:02 AM

Can anyone tell me definitively what exactly the color matrix adjustments do?

These two threads suggest that the first channel is affected by light from the second channel while the second channel is not affected (ie: R-G +9 adds green to red but leaves all other green [as well as blue] colors unaffected)
http://www.dvinfo.net/conf/showthread.php?t=86102

http://www.dvinfo.net/conf/showpost....2&postcount=15

however, the pictures posted by chris hurd in this thread, as well as my own experimentation seem to show that BOTH channels are definitely affected.

http://www.dvinfo.net/conf/showthrea...t=color+matrix

My eye though, is not keenly enough developed to decifer what is going on. Does anyone have a definitive answer?

Brandon Freeman · January 11th, 2008, 12:29 PM

I second this request. I cannot see what the exact effect is.

Pavel Sedlak · January 11th, 2008, 06:01 PM

Color matrix is the way how to transform colors (of an image).
http://www.c-sharpcorner.com/UploadF...mations05.aspx

R+G+B is not linear (1+1+1), brightness is a different in this representation, so changing of the gamma will change some colors (different brightness in the R, G, B make different colors). Color matrix this (a different unlinearity) "repair".

Cal Bickford · January 11th, 2008, 09:34 PM

That's interesting stuff Pavel but I'm not nearly clever enough to understand how to apply that conceptually to what is going on in my A1 : (

Pavel Sedlak · January 12th, 2008, 09:03 AM

you can make some test of colors A1 (on the same test image) with a different setting (gamma normal+matrix normal; gamma cine1+matrix1; gamma cine2 + matrix2) and look at for diferences (with all combinations like gamma cine1 and 2 with a normal matrix etc.).

Repeat this with a different lighting too (low, middle..)

Cal Bickford · January 12th, 2008, 09:20 AM

I understand what the overall "CMX" and "GAMMA" settings do, It's the individual variable matrices where I don't understand what is going on - For instance: what's the difference between R-G+9 and G-R+9 etc.

Pavel Sedlak · January 12th, 2008, 09:31 AM

no, they are not variable (only CMX1 and 2 for gamma cine1 and 2).

It is an correction, you can't change it (it is a special small transformation of colors, for using a different gamma).

---

How use individual matrices is the best see on the very good HD monitor (with vectorscope). I don't need this level of settings, I test some presets from Wolfgang's blog and I try change them (for my using). If I will have some time, I can test this (with profesional equipment), hope .-) .

Cal Bickford · January 14th, 2008, 03:08 AM

"Thank you for your inquiry about the XH A1 specifications. We value you
as a Canon customer and appreciate the opportunity to assist you.

Exactly how the color tint is affected during adjustment of the
individual color matrices of the Canon XH A1 is not published
information. Unfortunately, we do not have the references or resources
available to provide this information. I apologize for any
inconvenience this may cause.

Please let us know if we can be of any further assistance with your XH
A1.

Thank you for choosing Canon.

Sincerely,

Robert
Technical Support Representative"

read:

"Thank you for choosing Canon! Unfortunately we do not know how our own products work and/or are too cheap to hire qualified employees to support you technically. Thank you for choosing Canon!"

rofl, ok admit it everyone! ...If the only person at Canon who knows how these matrices actually work is some reclusive and unreachable staff engineer in a secluded basement office then you guys are just monkey-ing knobs until pretty pictures come out huh? : )

January 11th, 2008, 09:02 AM	#1
Cal Bickford Regular Crew Join Date: Jan 2007 Location: Austin, TX Posts: 157	Final answer on Color Matrix Ajustments??? Can anyone tell me definitively what exactly the color matrix adjustments do? These two threads suggest that the first channel is affected by light from the second channel while the second channel is not affected (ie: R-G +9 adds green to red but leaves all other green [as well as blue] colors unaffected) http://www.dvinfo.net/conf/showthread.php?t=86102 http://www.dvinfo.net/conf/showpost....2&postcount=15 however, the pictures posted by chris hurd in this thread, as well as my own experimentation seem to show that BOTH channels are definitely affected. http://www.dvinfo.net/conf/showthrea...t=color+matrix My eye though, is not keenly enough developed to decifer what is going on. Does anyone have a definitive answer?

January 11th, 2008, 12:29 PM	#2
Brandon Freeman Major Player Join Date: Feb 2007 Location: Boise, ID Posts: 226	I second this request. I cannot see what the exact effect is. __________________ Canon EOS 7D, Final Cut Studio 2

January 11th, 2008, 06:01 PM	#3
Pavel Sedlak Major Player Join Date: Feb 2007 Location: Prague Czech Republic Posts: 263	re Color matrix is the way how to transform colors (of an image). http://www.c-sharpcorner.com/UploadF...mations05.aspx R+G+B is not linear (1+1+1), brightness is a different in this representation, so changing of the gamma will change some colors (different brightness in the R, G, B make different colors). Color matrix this (a different unlinearity) "repair".

January 12th, 2008, 09:03 AM	#5
Pavel Sedlak Major Player Join Date: Feb 2007 Location: Prague Czech Republic Posts: 263	re you can make some test of colors A1 (on the same test image) with a different setting (gamma normal+matrix normal; gamma cine1+matrix1; gamma cine2 + matrix2) and look at for diferences (with all combinations like gamma cine1 and 2 with a normal matrix etc.). Repeat this with a different lighting too (low, middle..) Last edited by Pavel Sedlak; January 12th, 2008 at 09:15 AM. Reason: completion1

January 12th, 2008, 09:31 AM	#7
Pavel Sedlak Major Player Join Date: Feb 2007 Location: Prague Czech Republic Posts: 263	re no, they are not variable (only CMX1 and 2 for gamma cine1 and 2). It is an correction, you can't change it (it is a special small transformation of colors, for using a different gamma). --- How use individual matrices is the best see on the very good HD monitor (with vectorscope). I don't need this level of settings, I test some presets from Wolfgang's blog and I try change them (for my using). If I will have some time, I can test this (with profesional equipment), hope .-) . Last edited by Pavel Sedlak; January 12th, 2008 at 09:54 AM. Reason: comp.

January 11th, 2008, 09:34 PM	#4
Cal Bickford Regular Crew Join Date: Jan 2007 Location: Austin, TX Posts: 157	That's interesting stuff Pavel but I'm not nearly clever enough to understand how to apply that conceptually to what is going on in my A1 : (

January 12th, 2008, 09:20 AM	#6
Cal Bickford Regular Crew Join Date: Jan 2007 Location: Austin, TX Posts: 157	I understand what the overall "CMX" and "GAMMA" settings do, It's the individual variable matrices where I don't understand what is going on - For instance: what's the difference between R-G+9 and G-R+9 etc.

January 14th, 2008, 03:08 AM	#8
Cal Bickford Regular Crew Join Date: Jan 2007 Location: Austin, TX Posts: 157	"Thank you for your inquiry about the XH A1 specifications. We value you as a Canon customer and appreciate the opportunity to assist you. Exactly how the color tint is affected during adjustment of the individual color matrices of the Canon XH A1 is not published information. Unfortunately, we do not have the references or resources available to provide this information. I apologize for any inconvenience this may cause. Please let us know if we can be of any further assistance with your XH A1. Thank you for choosing Canon. Sincerely, Robert Technical Support Representative" read: "Thank you for choosing Canon! Unfortunately we do not know how our own products work and/or are too cheap to hire qualified employees to support you technically. Thank you for choosing Canon!" rofl, ok admit it everyone! ...If the only person at Canon who knows how these matrices actually work is some reclusive and unreachable staff engineer in a secluded basement office then you guys are just monkey-ing knobs until pretty pictures come out huh? : )