Color Calibration Resolution

Be warned: some technical information follows…

So – in the previous posting, you learned:

  1. That TIFF is the “master” of all digital formats – all RAW and DNG formats are really just tweaked TIFF.
  2. That Lightroom applies “wild guesses” of what they [Adobe] think the RAW images should look like.
  3. That the “wild guesses” Lightroom has been making have been unsatisfactory – the G9 RAW much more so.
  4. That I was even considering doing away with it.
  5. That my underwater case would arrive today [which it did, but more on that later].
  6. That I was on the verge of having a conniption.
  7. How to spell “conniption”.

The good new is that I have found a solution that will help me keep the pictures as they should appear… I think.

I have been reading about how to make the renderings of ACR or Lightroom match the regular output of what the JPG image looks like straight out of the camera, and I found a technique using an X-Rite ColorChecker and Thomas Fors‘ script. The gist of it is this: you take a picture of the color card in daylight-balanced light [two lights at 45 degree angles from the card on either side] at multiple exposures to ensure that you get it right. Then, you take that RAW file, open it in Photoshop, select four points on the image, and run the script. The script does some things – I have no clue what, except that it takes a long time – and then outputs a chart of what your camera calibration settings in the different color bands should be; e.g. Red Hue -16, Red Saturation 56 or other such values. You then open a regular RAW image [not the color chart] taken with that same camera and either in ACR or Lightroom, go to the Camera Calibration section and enter the values it spits out. Then, save it as the default for that camera and it will make those same adjustments to each RAW image taken by that camera. We have three, so we took three calibration shots with each camera and chose our favorite exposre.

Now – even this isn’t “right”, but it’s closer than ACR gets and it looks much more intense. I will be spending some time making minor adjustments, but I will be comparing the looks from Canon’s native software and Lighroom to make sure that I’m getting what I see when I look through the lens.

As a sample, this is what the script recommended for my 5D:

  • Red Hue: -18
  • Red Sat: 54
  • Green Hue: -9
  • Green Sat: -17
  • Blue Hue: 6
  • Blue Sat: -8

For the G9, the settings were quite different:

  • Red Hue: -15
  • Red Sat: 39
  • Green Hue: -1
  • Green Sat: 4
  • Blue Hue: -1
  • Blue Sat: 28

That’s quite different if you were to see what these settings do to the image. The results were that the RAW processed for the G9 did not look horrid anymore, but still was not quite right. It will definitely take some tweaking and a little more work. I just want our pictures to look their best.

And, phew! What a lot of work!

2 thoughts on “Color Calibration Resolution”

  1. hi, i have a 5D, and i am now battling to get my colors right. it really seems like a complicated issue. the script reccomended for your 5d, can that be applied to mine? if so where do i enter these values and are they set for all the white balance modes. also how is your 5D set up woth regards to white balance and kelvin?

    does the custom white balance work very well and can it be applied to studio flash lighting?

    kind regards dorian


  2. Well, I usually leave the 5D on Auto White Balance, but I”m going to stop doing that and use the Expo disc and other methods to get a correct WB before I shoot. In order to get the colors right, I would set the WB on both Lightroom and the DPP images to the same thing, if daylight, the daylight on both and make sure the K temps are the same instead of 5200 vs 5500.

    After setting that, I put in the values above to calibrate but noticed it wasn”t right still and ran the script several times to get closer. Finally, I took the final result, then used my own judgement and set the settings at:

    Red Hue -10
    Red Sat 28
    Grn Hue -5
    Grn Sat -19
    Blu Hue 0
    Blu Sat 0

    This seems to work for me, as I like a higher saturation and deeper contrast than what Lightroom was resolving to.

    You would enter these values into the Camera Calibration section of either Lighroom (in the Develop module) or in Adobe Camera RAW. If you”re not using RAW or these applications, but instead using Canon”s software, none of these settings are necessary.

    As for custom white balance in the studio, yes – it can. You can place a gray card in front of your subject and, with the proper exposure, engage the studio flash. Fill the frame with the gray color, then, once you take the picture, go into play mode and use the option to set the white balance.


Leave a Reply to Jeff Cancel reply

Fill in your details below or click an icon to log in: Logo

You are commenting using your account. Log Out /  Change )

Facebook photo

You are commenting using your Facebook account. Log Out /  Change )

Connecting to %s

%d bloggers like this: