Purple, beautiful purple

I once had a friend in high school who decided purple was their color – for everything.  Now a little bit of an interesting color can certainly add to an otherwise dull world but when you reach the monochrome level where everything is that color, suddenly it starts to wear on you a bit.  Fortunately they outgrew that infatuation, although purple is still part of their personal color palette.

And why not!?   I say go with what you like.  Besides, purple is an equally important color in photography because, well, there are purple things out there and as a good photographer I believe it’s important to show them accurately.  Which is why I’ve been frustrated over the past years about my purples.

Do you look at your images and see blue where your eye saw purple?  Have you tried to adjust the object’s color back to what you saw only to find you screw up the colors of other elements in the image?  Do you find yourself avoiding purple objects in your viewfinder?

Well, I finally learned what the problem is and found a solution.  Now I seek out purple objects – and my other colors are looking better as well.

First, why is purple so hard?  It appears your camera sensor has a hard time “seeing” it; that is, saving information that will accurately become purple later.

Here’s a color diagram to show the problem:

The black triangle represents the AdobeRGB color space, which is what most digital cameras use to define the colors they capture.  See the bottom part of the triangle, down where the purple is located?  See how little of the total color space actually makes it into the AdobeRGB space?  Most cameras just don’t have the processing power to deal accurately with that shortage of information so they use the color they do have good information on – blue.  And the reason adjusting the color in your computer usually doesn’t work is that you end up changing all the blues or reds in your image trying to salvage that little bit of purple.  Why?

Because Adobe (the system most people use for processing in some form) just isn’t that good at adjustments in this color area.

What to do?  Simple, use something other than Adobe’s processing to get the color right.

I was on a webinar a couple of weeks ago and the speaker talked about this problem, how Adobe’s processing “engine” just doesn’t do purple well.  He showed a way to generate an alternative calibration tool, one that could be applied to images and avoid Adobe’s shortcomings.

If correct color information is what’s lacking in Adobe’s processing “engine” then all you need do is give your computer the correct color information to use.  And that brings us to the X-rite Colorchecker Passport.

This device provides exact colors with defined data points in the color space.  Putting an image of the device into the software enables it to generate a calibration that can be applied to all other images made in the same light.  That calibration adjusts the rendering of color in the images different from Adobe’s “engine,” resulting in more accurate colors overall, especially purple.

To use this tool simply take a picture of the Colorchecker in the same light as your subject.

Bring it into your computer and convert it to a .DNG file (this is Adobe’s version of a RAW file) in Lightroom or Bridge.  Then drag that .DNG file into the Colorchecker software and tell it to generate a profile.

The software does that and saves the profile where Lightroom can find it later.  With your profile in hand you can go to the Camera Calibration section of the Develop module in Lightroom and apply that specific profile to your images.  It will correct the colors in your image using the information from the colors of the Colorchecker, giving a more precise rendering of your image.

I’ve been playing around with it, seeking out purple flowers and things, and find it to be amazing.  Not only are the purples better but I’m seeing the reds and oranges are looking more accurate as well.  Now I don’t curse my camera for it’s poor colors – I get more out of it than before!

Here are before and after images of a purple flower – see the difference?


You can read more about the Colorchecker at the X-rite website and a review (and more expanded instructions) at Luminous Landscape.  Now go out there and conquer your purples!