Mark Serrano Photography

Photographer. Retoucher. Storyteller

White Balance Adjustments with the Histogram

January 09, 2017

Today I'll show you how to use the histogram to make smart white balance adjustments, so that you'll have the confidence of a visually consistent color temperature across your photos.

What'll you need:

  • A gray card
  • A histogram
  • A reference photo

The Problem

When shooting with natural light, the light varies as time progresses. Often the color temperature drastically changes even if the exposure is maintained across the whole shoot. In this example photos, I was shooting multiple gowns for an Indian bridal catalog look. The shoot started in the morning and ended up in the afternoon. One of my main goals is to ensure that the photos are consistent color-wise.

Warm and Cold

Here are two photos that I took hours apart. The camera settings and composition are relatively the same, but the color temperatures are worlds apart. The photo on the left, our reference photo, has a warm cast overall; whereas, the photo on the right has a depressing bluish cast overall.

reference   bluish cast
reference photo bluish cast

Gray card

I used a gray card midway this shoot to maintain a baseline color temperature across the whole shoot. Here's the gray card image which gave me a 5400K reading.

    gray card     
  Gray Card  

Using Lightroom I applied this white balance reading to both photos. There was a slight warming up on the reference photo but not a game changer. There was also a slight improvement on the second photo though, but the bluish cast is still quote obvious. I need to make the second photo very warm to match the reference photo.

after gray card    before gray card
after gray card before gray card

The Key

I eyeballed the temperature slider until the photo is warm enough. The problem is half the time my eyes fool me. The first two adjustments were slightly off. So I thought maybe I can use the histogram to verify my color adjustments. The theory is if I bump the histogram to match the reference photo, I should arrive at the same overall color temperature.

Histogram Comparison

Let's compare the histogram of our two photos. The histogram on the reference photo doesn't show any blue areas on the far right side of the graph, but there is a slight yellow area peeking almost at the right side of the graph. However, on the second photo, the blue area is very obvious. This is a signed that the photo has a bluish cast.

reference    histogram
after gray card before gray card
bluish cast    histogram
bluish cast before gray card

The Process

To arrive at the target color temperature I moved the Temp slider towards the right until the blue area on the far right of the histogram is gone. I pushed it farther until I see a slight yellow area peeking at the far side of the graph again. The numbers gave me a 9100K reading. Notice how similar the histograms and color temperatures on both photos now.

reference    histogram
after gray card before gray card

Conclusion

Often a histogram is used to verify if photos are properly exposed. But it can also be used to verify white balance adjustments. With a proper histogram-based adjustment, we can ensure our photos look consistent across the whole shoot.

Credits

  • Photography by Mark Serrano
  • Models: Desteny Castaneda and Jordyn Volanti
  • Makeup by Jacqueline Meller-Vogt (Makeup By Jacquee)
  • Hair by Mariefel Lagatuz Westa
  • Wardrobe styling by Lupita Castaneda (AbbyBella Couture)
  • Wardrobe by Nesreen Abulaban (Style Me Couture)
  • Henna Tattoo by Healing Henna

Note: This is a repost from my old blog at http://markserranophoto.blogspot.com. I've lost access to that account unfortunately.

© Mark Serrano