Re: Archival image reproduction on Kodak Creo IQ3 scanner
Re: Archival image reproduction on Kodak Creo IQ3 scanner
- Subject: Re: Archival image reproduction on Kodak Creo IQ3 scanner
- From: Robin Myers <email@hidden>
- Date: Sat, 23 Jul 2011 08:05:23 -0700
When I made the measurements for ColorSage (Better Light's program using HP Artist), I selected as wide a range of colors as possible, with as wide a range of lightness as possible. As noted, having a wider sampling improves most color management profiling results and this one is no different. But it is not necessary to measure every possible blend of two pigments to get good sampling. For instance, in one painting it appeared that the artist had mixed a yellow pigment with a black pigment in a gradient between the two, so I sampled the yellow, the black and one blended color area between the two. It was not necessary to get every intervening mixture between the two blended colors.
In most artworks it actually becomes difficult to meet the 50 sample minimum requirement without repeating. With one painting of a cathedral at night, consisting of blends between only two basic colors, black and a yellow-orange, to get the 50 minimum measurements required sampling just about every possible mix between the two primary colors, with many measurements being repetitions.
Standard issues of measurement also apply. If the artwork has tiny areas and your spectrophotometer has a large measuring area, then the measurement will include the desired patch plus the surrounding colors, thus diluting the spectral result. Also, when using an i1Pro, or similar instrument, they must touch the artwork surface, so using these instruments is only possible on artworks such as dry oil or acrylic paintings where they will not be damaged by the contact. So if you want to measure pastels, pencil drawings, or other artworks with easily damaged surfaces, then you have to use a non-contact measuring device such as a Photo Research instrument.
If you want more information please feel free to contact me.
Robin Myers
Robin Myers Imaging
email@hidden
On Jul 23, 2011, at 5:36 AM, José Ángel Bueno García wrote:
> Don't worry. I was giving the point of view from the expensive dongle
> Robin Myers alluded.
>
> A bad capture can make a bad reproduction of a only 12 pigments
> artifact. You can make better aproaching to the original the way you
> introduce more knowledge and more technology.
>
> The use of a ColorChecker SG (140 patches) will give a better
> rendering than a ColorChecker Classic (24 patches).
>
> And sure that I haven't to tell that there are other parameters for
> image quality and the use of IT8.7/1 and IT8.7/2 targets for
> photographic materials.
>
> Sorry if I don't discover your curiosity. Maybe Mr. Robin Myers can
> shed more light.
>
> Salud
>
> Jose Bueno
>
>
>
> El día 23 de julio de 2011 11:49, Ernst Dinkla
> <email@hidden> escribió:
>> On 07/23/2011 01:07 PM, José Ángel Bueno García wrote:
>>>
>>> Hello:
>>>
>>> And what if I tell you that an art work of my friend Luis Palmero only
>>> have two pigments brush strokes?.
>>>
>>> Let's start a image capture color managed workflow with the selection
>>> of source of light and the camera. The limit is the gamut of your
>>> capturing device and your print device, and there is not a single
>>> solution for any combination.
>>>
>>> Robin Myers is talking from the experience, and we all know that time
>>> is money and that we are in a global crisis, but I would like to have
>>> time to spend in spectral measurements and multispectral camera like
>>> few years ago some museums did. Maybe they can't allow that now.
>>>
>>> Salud
>>>
>>> Jose Bueno
>>
>> Sorry if my curiosity was not expressed correctly in that message. I am
>> aware of the variety of art works. I know something about multispectral art
>> reproduction and I think that approach is sound like I think HP's creative
>> translation of that method should be sound. The thing I am curious about is
>> what a good patch for spectral measurement should look like in an art work.
>> Is the dominant spectral plot used (white background subtracted) or are more
>> pigments measured at the same patch and used in the computation? Should the
>> patch represent one pigment as good as possible? I see some issues there for
>> different styles of painting. The nice side of going this route is that
>> there are not more pigments classified for calibration than available in
>> that piece of art (like the example of two you quoted). Unlike using a
>> pigment color checker chart that has 800+ pigment patches which could
>> interfere with one another in the process while the original art work may
>> only contain 12 pigments.
>>
>>
>> --
>> Met vriendelijke groeten, Ernst
>>
>>
>> Dinkla Gallery Canvas Wrap Actions
>>
>> | Dinkla Grafische Techniek |
>> | www.pigment-print.com |
>> | ( unvollendet ) |
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