Color Capture Challenges


Today’s Question: When I see yellow flowers with the naked eye, I see them as having more lemony, light yellow overtones. But when I photograph them I see they usually turn out with more orange overtones and it seems difficult to capture their natural color from the start. Seems I always am fiddling with Lightroom temperature and exposure adjustments to try to make the yellows look natural. I have similar challenges when I photograph reds. And, not only do I have temperature issues, it seems difficult to capture details. Any advice?

Tim’s Quick Answer: There are two key issues here. One is a color temperature that isn’t quite right, and the other is an exposure that is too bright for at least one of the channels for the image. I suggest starting with a custom white balance setting for this type of scenario, and checking your exposure carefully using histograms for individual color channels rather than only for overall luminance.

More Detail: In theory the accuracy of color in a raw capture isn’t critical, as you can always fine-tune the Temperature and Tint adjustments in post-processing. With a raw capture, if you apply those color adjustments as part of the original processing of the raw capture then there is no penalty in terms of image quality.

Of course, in many cases you may want to ensure the color in the original capture is as accurate as possible, so that you have a better starting point in post-processing. A custom white balance setting in the camera can help with this.

The specifics of implementing this option will vary from one camera to the next, but in general the process involves taking a picture of a neutral subject (such as a blank sheet of paper or a gray card) under the same lighting as the subject you’ll photograph. Then set that image as the reference photo for a custom white balance setting within the camera. Set the white balance preset to the appropriate “custom” setting, and the color will be adjusted based on the color of the light for subsequent captures.

This does mean the beneficial influence of color (such as golden light in the late afternoon) will be neutralized, which isn’t always ideal. But with this approach you’ll have a more accurate starting point for your color. The result will be as though the subject was illuminated by pure white light.

As for the loss of detail for key colors, this generally means that one (or two) color channels has been over-exposed. This is just like clipping highlights to pure white, except that it doesn’t involve all three channels.

So, for example, if the red channel is over-exposed, you’ll lose texture and detail in a photo of a red rose. The solution is to reduce the exposure so that all three color channels show no clipping for the highlights. To evaluate this I recommend setting your camera to display a “full color” histogram that displays an individual histogram for each of the three color channels (red, green, and blue). This level of detail can’t easily be determined with a luminance histogram that is based on brightness values for the overall image.