NoBs Digital Dogbowl

Understanding White Balance

In the modern world of Digital Cameras one thing that comes up in conversations with other photographers is White Balance. This is code for color because today’s cameras see color differently than film cameras. In the old darkroom ages we would purchase film that color balanced as to what we were shooting. If we were going to shot outside we would pick up Daylight Balanced film. Shooting inside grab some Tungsten balance film for incandescent lighting. These were our only two choices. Shoot the wrong film and daylight film would go red or really golden inside or for artsy look tungsten film would go blue outside. This was because film manufacturers understood that outdoor sunlight was cyan / blue light from the sky or to put it in math terms a color temp of 5500 kelvin. The indoor light was coming from a red hot filament burning in the bulb so it was very reddish or 7200 kelvin.

However if we had to shoot in an area being lighted by fluorescent lights then we had to break out the light magenta filters to balance the greenish light coming off these lights. For any other light we just hoped that the lab would take the time to color correct.

Which now brings us to how the digital camera “sees the color” of a image. In many of the consumer cameras that are called Point and Shoot, they are set for AWB or Auto White Balance. In the space of time it takes to press the shutter the camera not only figures out the exposure but what appears to white in the frame to remove any color cast from different lighting sources. Outside in bright sunshine or inside at a basketball game the camera balances the light for good colors and skin tones.

In more expensive cameras (The type with zoom lens or they types that you can put other lens on called Digital Single Lens Reflex DSLR) you can use AWB or even set the camera for different lighting like Sun, Cloudy, Shade, Fluorescent,Flash and the like. This can be very helpful for those who want more control over the look of an image. You can even use some of these setting to add more warmth to a image. Setting the camera on Shade will warm up a Daylight image. The problem comes in if you move from one lighting setup to another.

I had a wedding shooter send me some images she shot at a wedding where she was outside photographing the Bride and Groom in Daylight mode and ran inside to catch her coming into the church. All the first images inside were deep reddish brown and she was in panic. Using the eyedropper color correction I mention earlier corrected the images but a set Color Balance does require more attention.

So why would you want to shoot anything but AWB? If you are shooting in Jpeg mode (standard setting for point and shoot and even pro cameras) and you want all the images to have the same color balance or look you could be in trouble. Each time you push the shutter the camera will take a new look at the image and pick a color balance just for that image. Let’s say you taking photos of four women wearing a different shade of white dress. For each woman the camera will “look” at her white dress and come up with different color setting. While the dresses will all look alike the skin tones will be off for each one. Plus when they see the images they will know that their dresses were not the same and mention it (sometimes in quite a stressed voice).Having the camera set for one color balance will mean the color balance will remain the same for all shots. As mentioned you just have to keep this in mind for the next setup.

Is there a way around always changing the White Balance if you want colors to be consistent? Yes but mostly for those with those more expensive cameras and Photoshop. It is one of most inexpensive pieces of camera gear I found call a Gray Card. If there still any Camera Stores around you they will be by the books and only cost about $5 to $10. Some are even made for digital cameras made from plastic with not just gray but black and white on them. These are standard for cameras so all you have to do is sometime in your session take a shot of it under the lighting you are shooting. When you open up all the images in Photoshop (or Photoshop Elements) go to this image and using the eyedropper tool and center eyedropper (Middle Gray) click on the gray card and save this setting. This is done by clicking on the Save button in either Levels or Curves and save that setting in the same folder as the images. Then when you go to the other images you just bring up Adjustment layer for Levels or Curves and click on Load. You will see your saved setting and just open it, Auto correction done. If you just have a few images you can create an Adjustment layer and drag and drop it onto any other open image and Photoshop will make a copy of this layer.

Want to move up to the next level? You can shoot AWB in RAW (an image format found in a lot DSLR and higher end Point and Shoots) because in RAW it doesn’t matter. This format can be changed to any color temperature for adjustment. Plus in Photoshop and Photoshop Elements you can open a group of RAW images in the RAW processor and color correct them all at the same time. This is along with exposure corrections and bumping up the contrast and saturation of images. The advantage to shooting AWB in RAW is that you are letting the camera do most of the work while you just need to nudge the color to match later.

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