Color Checker Passport does EXTREME color correction.
I’m sure you’ve encountered this problem before. Lighting conditions that are so bad that even a custom white balance in camera simply cannot fix. And you don’t have time or perhaps don’t have the skill to correct for these color errors on your own in post production. Even if you do, it’s not time well spent. Instead, here is how you get the best color from these extreme lighting conditions.
First off, my example photo was shot under a street lamp at night which has a very strong amber color cast to it. And even building a custom white balance in-camera simply cannot correct for this wide of a range of color shift. And adjusting the white point in Lightroom gets me a similar result as we have simply maxed out the available adjustment range within Adobe camera raw.
The color here is simply unacceptable, even with the custom white balance I generated in-camera using the neutral gray target on the X-Rite ColorChecker Passport. (It is VERY bad without the custom white balance.)
To fix this, I exported the camera raw file, in this case it was a Nikon NEF file, from Adobe Lightroom into an Adobe DNG file which is their own “digital negative” raw file format. It retains all of the original raw data as the NEF file but essentially “translates” that into an Adobe friendly format for all of their other software. Once exported as a DNG file, I opened the Adobe DNG Profile Editor and then used the Chart tab to place the colored dots onto the corresponding colored squares on the ColorChecker chart in the image. (Download the Beta version of the Adobe DNG Profile Editor Here.)
Normally, this is all that needs to be done to create a custom camera profile… Except in this case, it gives me an error message instead. That message is telling me that it cannot find the gray squares to set the correct white balance and generate the custom camera profile. So we have to tweak the calibration some in order to get it close enough for the system to take over.
This means we have to switch to the Color Matrices tab and tweak the white balance calibration to get the color closer to neutral before the custom chart can be generated. These sliders allow the white balance to be adjusted outside of the normal range and to tweak each color channel independently. As you can see in the screen capture, I made significant adjustments to the calibration by eye to get the color of the chart closer to the actual colors. We don’t need to make it perfect, just closer to neutral so that the software can properly generate the profile.
Now that we have the color manually adjusted to be within the limits of Adobe camera raw, we can then create the proper color tables for the custom camera profile. Now go back to the Chart tab and it will then automatically create the color tables. Once that is done, simply export the DNG profile (File > Export *camera model* Profile) and it will save that profile into the proper location for Adobe products to find it. Now re-load Lightroom or Photoshop and it will allow you to select the custom camera profile from the drop down menu on the Camera Calibration tab.
With the new camera profile selected, use the white point dropper tool and select the neutral square in the image and it will then correct the color to nearly match the actual color of the ColorChecker Passport target.
Anyone who wants to play along, here is the DNG file used to create the custom profile.
(Right Click: Save Link As) Amber_Street_Lamp.dng (23.3mb Adobe DNG format.)
And for those who prefer to watch my tutorial videos:
Don’t forget to watch the video in Full Screen HD mode for the best quality.