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!