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  1. #1
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    Aug 2011
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    Default Color measurement device

    Hi AMIEN,

    I try to get some information about what is optimal solution for color measurement instrument like spectrophotometers.

    By optimal i mean that to be able to measure wet and dry samples regarding quality control and formulation of artistic colours.

    I also heard that colours formulation based in instrumental device is not practised by any of comercial manufacturers due to the fact that artistic colours meant to be pigmented the least numbers of pigments as possible. Not like wg. automotive paints where output color matters with no regards what kind and numbers of pigment added to formulation.

    I also wonder what is the practical issue about optical geometry within particular spectrophotometers.

    I found out that there is two major geometry that are used: 45/0 angle and spherical d/8.

    Generaly it is said that 45/0 is better for quality control due to be like human eye perception, and d/8 geometry is better for colours formulation. What is the differences in practical?

    I review some of the models within device manufacturer I mensioned above wg. :

    1) from X-Rite http://www.xrite.com/product_overview.aspx?ID=1208 which is the only non-contact device I found

    2) from Konica Minolta http://www.konicaminolta.com/instrum...014_01_01.html

    3) from Datacolor http://industrial.datacolor.com/port...datacolor-400/

    All of them offers quite the same possibilities. Do You have any practical knowledge concerning this devices.

    What would You recommend for measuring color of artistic colours?

    I will be very thankful for any sugestions.

    Best regards,

    chemiboy

  2. #2
    Join Date
    Jun 2006
    Posts
    9,067

    Default Color measurement instruments

    Quote Originally Posted by chemiboy View Post
    Hi AMIEN,

    I try to get some information about what is optimal solution for color measurement instrument like spectrophotometers.

    By optimal i mean that to be able to measure wet and dry samples regarding quality control and formulation of artistic colours.

    I also heard that colours formulation based in instrumental device is not practised by any of comercial manufacturers due to the fact that artistic colours meant to be pigmented the least numbers of pigments as possible. Not like wg. automotive paints where output color matters with no regards what kind and numbers of pigment added to formulation.

    I also wonder what is the practical issue about optical geometry within particular spectrophotometers.

    I found out that there is two major geometry that are used: 45/0 angle and spherical d/8.

    Generaly it is said that 45/0 is better for quality control due to be like human eye perception, and d/8 geometry is better for colours formulation. What is the differences in practical?

    I review some of the models within device manufacturer I mensioned above wg. :

    1) from X-Rite http://www.xrite.com/product_overview.aspx?ID=1208 which is the only non-contact device I found

    2) from Konica Minolta http://www.konicaminolta.com/instrum...014_01_01.html

    3) from Datacolor http://industrial.datacolor.com/port...datacolor-400/

    All of them offers quite the same possibilities. Do You have any practical knowledge concerning this devices.

    What would You recommend for measuring color of artistic colours?

    I will be very thankful for any sugestions.

    Best regards,

    chemiboy
    We use a BYK Gardner Color Guide, a portable spectrophotometer with 45/0 and a 20 mm port. See it at <http://www.byk.com/en/instruments/color.html>, though the product name has been changed to "spectro-guide." This instrument can be programmed to read in many different color languages, though we use CIE L*a*b*. The color temperature of the lamp is D65 and specular reflection is excluded -- all according to the specifications of ASTM D4303. We only read dried samples of paint that have been applied to a substrate in a specified manner. It is almost impossible to read wet paint -- the port is open, and stuff can get in there are ruin the instrument.

    We got a reconditioned Color Guide at a substantial discount: only ~$4,000.00USD, if we remember correctly. We calibrate it before use using the supplied calibration tiles and have it factory-calibrated once a year for ~$700.00USD.

    Yes, many paint-makers do not use instruments. They have a standard sample of what a color should look like and compare a new batch of paint with the standard, by eye -- a very practiced eye! -- in daylight conditions. And yes, many artist's paints are single-colorant paints, though not pastels or colored pencils.
    Last edited by AMIEN; 03-28-2012 at 04:04 PM.
    The AMIEN Staff

  3. #3
    Join Date
    Aug 2011
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    27

    Default geometry

    Quote Originally Posted by AMIEN View Post
    We use a BYK Gardner Color Guide, a portable spectrophotometer with 45/0 and a 20 mm port. See it at <http://www.byk.com/en/instruments/color.html>, though the product name has been changed to "spectro-guide." This instrument can be programmed to read in many different color languages, though we use CIE L*a*b*. The color temperature of the lamp is D65 and specular reflection is excluded -- all according to the specifications of ASTM D4303. We only read dried samples of paint that have been applied to a substrate in a specified manner. It is almost impossible to read wet paint -- the port is open, and stuff can get in there are ruin the instrument.
    Thank You very much.

    So it apears that 45/0 geometry is much more accurate within color control. but what about formulation and color matching. I found out that for this aplication d/8 is better due to better accuracy concerning pigment concentration and color appearance regardless of sample texture and gloss.

    Can formulation of colours be done appropriate using 45/0 as well as d/8 geometry?

    this article ( http://www.dfisica.ubi.pt/~hgil/P.V....-geometria.pdf) is quite informative but it's "just" theory and I would like to know more from prectical point of view.

  4. #4
    Join Date
    Jun 2006
    Posts
    9,067

    Default Geometry and color formulation

    Quote Originally Posted by chemiboy View Post
    Thank You very much.

    So it apears that 45/0 geometry is much more accurate within color control. but what about formulation and color matching. I found out that for this aplication d/8 is better due to better accuracy concerning pigment concentration and color appearance regardless of sample texture and gloss.

    Can formulation of colours be done appropriate using 45/0 as well as d/8 geometry?

    this article ( http://www.dfisica.ubi.pt/~hgil/P.V....-geometria.pdf) is quite informative but it's "just" theory and I would like to know more from prectical point of view.
    chemiboy,

    Since we have been color matching and evaluating color and its changes for 30+ years, we would use our eyes, not a spectrophotometer, for paint formulation: That's as practical as you can get.

    If you do not have experience or training in color evaluation/matching with your eyes, may we suggest you go to work for an experienced artist's paint maker and get the training?
    The AMIEN Staff

  5. #5
    Join Date
    Feb 2010
    Location
    Rural Upstate NY.
    Posts
    254

    Default Our practical experience

    Quote Originally Posted by chemiboy View Post
    Thank You very much.

    So it apears that 45/0 geometry is much more accurate within color control. but what about formulation and color matching. I found out that for this aplication d/8 is better due to better accuracy concerning pigment concentration and color appearance regardless of sample texture and gloss.

    Can formulation of colours be done appropriate using 45/0 as well as d/8 geometry?

    this article ( http://www.dfisica.ubi.pt/~hgil/P.V....-geometria.pdf) is quite informative but it's "just" theory and I would like to know more from prectical point of view.
    Hi Chemiboy -

    In house we have both, and from a practical standpoint they have felt comparable for accuracy. The one caveat is that you should only compare data taken within one system or the other for best correlation.

    We have never had luck accurately measuring wet samples on a spherical spectro as it required a film over the wet product to prevent mechanical damage. Our 45/0 works has worked very well for wet and dry samples, and we use the X-Rite system you reference extensively for that reason. This is especially true where color development and quality checks requires measuring wet films, such as when producing oil paints as the time needed for films to fully dry make taking measurements at various steps in the manufacturing process of a particular batch impractical. The instrument has a very sophisticated ability to adjust for the influence of ambient light and its readings have been quite accurate.

    On a final note, no matter what the spectro says, at the end of the day the human eye is always the last arbitrator. We use spectros as a way to record data and to get close to perfect color matches - sometimes extremely close.....but it still needs to pass inspection by some very practiced human eyes. So in that sense we do agree with AMIEN and would encourage you to not rely solely on instruments for color matching or development.

    Hope that helps.
    Sarah Sands

    AMIEN Moderator
    Technical Services Supervisor
    Golden Artist Colors
    Williamsburg Handmade Oil Colors

  6. #6
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    Jun 2006
    Posts
    9,067

    Default Color measurement instruments

    Quote Originally Posted by Sarah Sands View Post
    Hi Chemiboy -

    In house we have both, and from a practical standpoint they have felt comparable for accuracy. The one caveat is that you should only compare data taken within one system or the other for best correlation.

    We have never had luck accurately measuring wet samples on a spherical spectro as it required a film over the wet product to prevent mechanical damage. Our 45/0 works has worked very well for wet and dry samples, and we use the X-Rite system you reference extensively for that reason. This is especially true where color development and quality checks requires measuring wet films, such as when producing oil paints as the time needed for films to fully dry make taking measurements at various steps in the manufacturing process of a particular batch impractical. The instrument has a very sophisticated ability to adjust for the influence of ambient light and its readings have been quite accurate.

    On a final note, no matter what the spectro says, at the end of the day the human eye is always the last arbitrator. We use spectros as a way to record data and to get close to perfect color matches - sometimes extremely close.....but it still needs to pass inspection by some very practiced human eyes. So in that sense we do agree with AMIEN and would encourage you to not rely solely on instruments for color matching or development.

    Hope that helps.
    Sarah Sands,

    Excellent, and we especially enjoyed the last paragraph. Thank you.
    The AMIEN Staff

  7. #7
    Join Date
    Aug 2011
    Posts
    27

    Default

    Quote Originally Posted by Sarah Sands View Post
    Hi Chemiboy -

    In house we have both, and from a practical standpoint they have felt comparable for accuracy. The one caveat is that you should only compare data taken within one system or the other for best correlation.

    We have never had luck accurately measuring wet samples on a spherical spectro as it required a film over the wet product to prevent mechanical damage. Our 45/0 works has worked very well for wet and dry samples, and we use the X-Rite system you reference extensively for that reason. This is especially true where color development and quality checks requires measuring wet films, such as when producing oil paints as the time needed for films to fully dry make taking measurements at various steps in the manufacturing process of a particular batch impractical. The instrument has a very sophisticated ability to adjust for the influence of ambient light and its readings have been quite accurate.

    On a final note, no matter what the spectro says, at the end of the day the human eye is always the last arbitrator. We use spectros as a way to record data and to get close to perfect color matches - sometimes extremely close.....but it still needs to pass inspection by some very practiced human eyes. So in that sense we do agree with AMIEN and would encourage you to not rely solely on instruments for color matching or development.

    Hope that helps.
    Sarah Sands,

    Thank You very much. That was exactly what I needed to know. Pure straight practical informations.

    Big cheers for You

  8. #8
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    Aug 2011
    Posts
    27

    Default

    Quote Originally Posted by AMIEN View Post
    Sarah Sands,

    Excellent, and we especially enjoyed the last paragraph. Thank you.
    Surely human eye is the most unprecedented device, but among every person perception is different. Color is not a exception, whereas data from device's "artificial eye" is mathematical consistent assuming that all of the optic parts are repeatable.

    And of course both devices, biological eye and any optical device sure be one each other complementation.

  9. #9
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    Jun 2006
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    9,067

    Default Perception

    Quote Originally Posted by chemiboy View Post
    Surely human eye is the most unprecedented device, but among every person perception is different. Color is not a exception, whereas data from device's "artificial eye" is mathematical consistent assuming that all of the optic parts are repeatable.

    And of course both devices, biological eye and any optical device sure be one each other complementation.
    chemiboy,

    An instrument does not look at a painting and enjoy the interplay of shape, form, color, and light. Only the human eye/brain can do that. That's why the practiced eye is the final arbiter in color perception/matching/evaluation. We learned this a very long time ago in a course on color science at the Munsell Color Science lab at the Rensselaer Polytechnic Institute -- at the time the first and best color science program in the US. One of the instructors, the late Frank Stanziola, kept reminding us that instruments were no substitute for the practiced eye.

    We suggest again that you not rely on instruments alone, and get your eyes/brain trained.
    The AMIEN Staff

  10. #10
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    Aug 2011
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    27

    Default eye substitute

    Quote Originally Posted by AMIEN View Post
    chemiboy,

    An instrument does not look at a painting and enjoy the interplay of shape, form, color, and light. Only the human eye/brain can do that. That's why the practiced eye is the final arbiter in color perception/matching/evaluation. We learned this a very long time ago in a course on color science at the Munsell Color Science lab at the Rensselaer Polytechnic Institute -- at the time the first and best color science program in the US. One of the instructors, the late Frank Stanziola, kept reminding us that instruments were no substitute for the practiced eye.

    We suggest again that you not rely on instruments alone, and get your eyes/brain trained.
    I totally agree with You AMIEN. I don't even think to substitute eye with instrument, just to have some artificial cyclope to help ;)

    Thank You for all Your comments

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