ACR Calibrator

[AndreG]

Hi,
What would be the best practice to obtain a uniform and exact color rendition using the ACR Calibrator Script from http://chromoholics.com?

Here is the scenario : we are a team of photographers that shoot Equestrian Competitions using DSM2 and DSM3 cameras. The fun begins when I process thousands of  photos and I try to present a uniform color rendition and saturation. Lightroom is my Raw processor.  We tried Whibal with partial satisfaction, photoVision target with better color rendition and uniformity with the cameras personalized White Balance option.

Michael's and Jeff excellent video « Camera Raw » explained the ACR Calibrator  camera color calibration technique.  The initial tests are conclusive but naturally the light changes all the time in the field.  I am considering the creation of calibrations at different light temperatures during the day for each camera and use them to develop the photos at the importing phase of Lightroom and tweek them accordingly.

Am I on an impossible mission?

Thank you for your time.

Andre

[rdonson]

The initial tests are conclusive but naturally the light changes all the time in the field.

Am I on an impossible mission?

Andre
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You've stated the problem.  Sure sounds like mission impossible to me.

[sojournerphoto]

You've stated the problem.  Sure sounds like mission impossible to me.
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If you calibrate in direct sunlight (i.e. about D50) then you will probably find that colour rendering at all other colour temps is also improved. That would be a start and may be enough

Mike

[neil snape]

According to Danny Pascale at Bibble;
If you use ACR to calibrate for much of the near daylight spectrum one calibration should suffice. If you use a low energy light , such as tungsten then you should have a separate calibration for this light source.

In LightRoom you can process with the settings for each individual camera if I remember right. Must have seen a Podcast on this.

[AndreG]

According to Danny Pascale at Bibble;
If you use ACR to calibrate for much of the near daylight spectrum one calibration should suffice. If you use a low energy light , such as tungsten then you should have a separate calibration for this light source.

In LightRoom you can process with the settings for each individual camera if I remember right. Must have seen a Podcast on this.
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Thank you for your response, the subject is rather complex and it is difficult to find texts on how to impliment it.

Thank you for the reference at Bibble and your view on the subject. Yes, you are right your can set settings ofr a particular camera Here a a reference:

[a href=\"http://www.computer-darkroom.com/lr_camera/camera-defaults.htm]http://www.computer-darkroom.com/lr_camera...ra-defaults.htm[/url]

The first tests are conclusive and I feel it is worth the time and effort.

Thank you again.

[duraace]

This worked for me, using CS3 and Lightroom:


Right click on the link to his script

http://21stcenturyshoebox.com/downloads/AC...rator-L-v28.jsx

and save it (either in some folder in your home directory, or in Photoshop's scripts directory under Presets>Scripts wherever Photoshop is located on your machine). If you put it in the Photoshop scripts directory, it should appear when you relaunch Photoshop under File>Scripts; or if you put it somewhere else, use File>Scripts>Browse... and navigate to where you put it. First you need to take a raw image of a color checker chart in good sunlight with the sun about 45 degrees off axis from the camera. You might want to bracket the exposure in 1/3 stop steps, and choose the one that has middle gray at the right place in whatever color space you're working with. Develop the raw file in ACR with *neutral* settings (no saturation, contrast, exposure, brightness etc corrections; however do use the white balance and tint sliders to get the neutral gray square to actually be gray) and open directly in Photoshop; use the pen tool to draw a path from the upper left to lower left to lower right to upper right squares of the chart; then launch the script and go do something else while it churns away. The output of the script is a set of calibration presets which you can enter as calibration defaults in ACR.