Rob Sheppard is the author/photographer of over 25 books, a well-known speaker and workshop leader, and is editor-at-large and columnist for the prestigious Outdoor Photographer magazine. As author/photographer, Sheppard has written hundreds of articles about photography and nature, plus books ranging from guides to photography such as The Magic of Digital Nature Photography and the Kodak Guide to Digital Photography to books about Photoshop and Lightroom including Adobe Photoshop Lightroom 2 for Digital Photographers Only and The New Epson Complete Guide to Digital Printing.
Please visit Rob's website and his blog.
In this first contribution to Visionary Photographers, Rob addresses that most elusive and confusing of subjects, White Balance. Rob's views on Automatic White Balance can play an important role in your own nature and outdoor photography.
White balance is a new technology for most photographers. It was not part of film work. It is, however, a very important part of the craft of the digital photographer.
White balance comes from the video field. I worked in video through the 1980s and 1990s. A standard part of our working procedure was to set white balance for every set up, meaning every change in the light. There was no such thing as auto white balance. You had to literally balance your camera’s electronics to make the light neutral by using a white sheet of paper.
Yet this was a tremendous help over shooting film. You no longer had to use special filters or worry about bad color on your subject. I remember the pain of doing photo shoots for businesses then. For example, I did work for a client who had a manufacturing facility. The lighting conditions were all over the place. I used a special color-temperature meter and color correction gels – they mostly worked, but had to be changed for every shot. Plus they colored and darkened the view through the viewfinder. All in all, a big nuisance. But with video and white balance, you could get great color with almost any light, do it quickly and get excellent color (lights that do not have a complete spectrum, such as sodium vapor lights, still cannot be white balanced because there are not enough colors in the light to do it).
Now white balance is a key part of digital cameras and a tremendous benefit to all photographers. It is well worth learning and understanding as a new part of the craft of photography. Yet, in my classes at BetterPhoto.com and my workshops across the country, I find that white balance is still not well understood. Most photographers are using auto white balance, and while it can work, often it is giving them less than the best color or workflow in the computer. I can frequently recognize that a photo was shot with auto white balance before I even see the metadata. This is because auto white balance often gives a compromise for colors, and while convenient, it either makes more work in post processing or you are stuck with less than optimum color.
First, let’s look at why auto white balance, or AWB, can be a problem:
- AWB is an automated compromise, and as such, rarely matches real-world conditions. It is an automated process based on engineers in Japan trying to cope with a huge variety of scenes taken by people from all over the world, scenes those engineers will never see.
- AWB is inconsistent. It is common to shoot a subject with a zoom at the wide setting and then with the telephoto setting and get two different white balances in the resulting photos. That may be fine for snapshots, but for really good color work, AWB rarely gives fully accurate or consistent color.
- Outdoor AWB shows a consistent compromise in color, usually from blue contamination of all colors. This causes a problem in the computer because photographers will often adjust the image based on what is seen on the monitor (compromised color) rather than what was accurate or appropriate for the scene. All adjustments are then biased based on what you see in that AWB.
- AWB typically makes outdoor photos have colors with less saturation because of the blue contamination in the colors and a blue cast to neutral tones. This is what is so common that I recognize it and bet on it even before seeing the metadata.
- AWB typically takes some of the drama out of sunrise and sunset because it doesn’t “know” that such conditions are supposed to have a color cast to the light.
©2009,Rob Sheppard
AWB setting
©2009,Rob Sheppard
Sun setting
©2009,Rob Sheppard
Cloudy setting
These three photos show the power of setting white balance. This is a sunset scene in the Loxahatchee Wildlife Refuge in Florida, a northern part of the Everglades ecosystem. It was shot with AWB, Sun and Cloudy settings. The AWB shot is the least sunset like. Some of the color has been removed.
The Sun setting gives the sunset a very natural and believable appearance. Cloudy intensifies the warmth of the sunset colors. I believe there is no arbitrarily correct setting for this shot as we all see sunsets differently – color is not an absolute but is highly interpreted by our minds in reference to other colors nearby, our expectations for a scene, memory colors of certain subjects, and more.
Many people expect sunsets to look like the one in the Cloudy scene because it is a lot like images shot with Kodachrome and Velvia slide film, the most common films used for nature in the past. Paul Simon didn’t write his song Kodachrome because it gave real colors! The point of these three images is to show how much color is affected by your choice of white balance and how poorly AWB can do.
It is easy to forget that when you are adjusting in front of a monitor, the only reference you have is what is in front of you, i.e., the AWB scene. You are not adjusting to a "standard reference", but to a subjective visual reference based on how your eyes see the image -- this has nothing to do with calibration of the monitor but about "calibrating" your internal sense of color. So just because you calibrated your monitor does not mean you will get accurate color. Calibration doesn’t “care” if your colors are originally accurate or not – it only wants to ensure your colors display “accurately” based on what is actually recorded in the photo, which could be the “accurate” display of an inaccurately captured color.
Calibrating a monitor is very important, but has little to do with white balance. You can have a perfectly calibrated poor white balance or a perfectly calibrated great white balance and your monitor and calibration won't care. Calibration gives you a consistent, predictable work environment, which is important.
It is possible to adjust an image visually to a better white balance even with AWB by always using a standard image with good clean color as a visual reference. Put it on your screen, study it, then go back and forth to the photo you are working with. You will then start to see color issues better, but this sort of thing is a nuisance for most photographers.
In my experience with a lot of camera brands, the preset, preloaded white balance settings of a camera consistently do a better job in matching real world scenes when they are set to match the conditions they represent. This would be using a Sun white balance setting for sunny conditions, Shade for shade, Tungsten for indoor lights and so forth.
©2009,Rob Sheppard
AWB setting
In the picture above, we see a shot of a waterfall with a wealth of neutral tones. I would never shoot such a scene with AWB as it will almost always make the neutral water look bluish. That just never looks right to me and weakens the shot. Shooting with Shade or Cloudy white balance will help remove the blue color by more accurately balancing the camera’s response to the light with the actual color of the light. I have sometimes found this type of shot to be a challenge even for these settings because of all the green light from the trees and nearby foliage. In that case, I have found that setting a custom white balance can clean up the colors quite nicely.
Many photographers experiment a bit and choose a white balance setting that actually warms up the scene because this is how we always used to shoot with film – warming filters were often recommended. In addition, Fuji, Kodak and Agfa films all had warm biases. Whether this is "accurate" or not is less relevant than this is what people expect in photographs. Research has shown that people prefer photos with a slight warmth to them.
©2009,Rob Sheppard
Cloudy setting
This is a photograph of Otter Cliffs in Acadia National Park at sunrise. It has a nice warm color to it. AWB will usually destroy such lovely colors. As a nature photographer, I feel the color cast of the scene is important because it is bathed by a very colored light right at sunrise. This was shot with a Cloudy setting to ensure that this color was captured by the camera.
©2009,Rob Sheppard
Shade setting
Shown above is an image of a child being carried by his mother in Peru, with traditional blanket wrapping technique. It is important that the skin tones are clean and accurate. This type of shot, where the skin is in the shade, will frequently be captured by AWB with a blue cast. That means work correcting that color as skin tone with blue in it is not very appealing. Shooting with a Shade white balance can ensure better skin color in this sort of situation.
©2009,Rob Sheppard
Cloudy setting
One reason why cloudy day shots often look unappealing is because they look gray with a slight blue cast, they look dingy and lack color. That slight blue cast can really take away saturation from colors, yet it is so common with AWB. I can’t imagine shooting an image like the street scene with anything other than Cloudy white balance or a custom white balance. Changing the camera for specific conditions is no harder than adjusting a shutter speed or f-stop once you acquire the habit, and the results can be definitely worth that slight extra effort.
Frequently, I hear, “but I shoot with RAW, therefore I can change my white balance.” That is true, you can change the white balance, but not the word “change” – that implies more choices and an increased workflow, not necessarily a good thing.
When you set a specific white balance, that white balance is interpreted by your RAW program when you open the RAW image into it. The program also interprets and gives a specific white balance based on the white balance "set" by AWB. The problem with the latter is inconsistency, less optimum colors to start with, and an added step in workflow.
I rarely change my white balance in RAW because I set it at the camera. I therefore rarely have that step or decision to make in the computer, or even to worry about. And there must be a decision with white balance. What is the correct white balance? If you have several variations due to AWB, which do you choose?
Some photographers will shoot a gray card and use the white-balance eyedropper on it to neutralize color casts. This works (and works well) if you are shooting in a studio and have totally controlled light from flash or quartz lights. When you are outside, this does not work since the color of real-world light is far more complex than that.
For example, at dawn and dusk, we expect to have a color cast to the light. At midday, we don't, but if a photo is "purely" adjusted to a neutral gray, it visually often looks blue to the average person. In addition, if you have several photos of a person shot with different focal lengths, you will very often get different skin color with AWB. Which is the correct color? Now you have that decision to deal with and an added workflow.
Custom white balance, where you set white balance by actually using a white or gray card, can be an acceptable way of getting good and consistent color for a scene. For people who like to totally control their entire photo process, this may be the best way for them to work. When I was in video production, as I noted, there was no such thing as AWB or preset white balance. We white balanced every scene, every subject by putting a white card into the scene and using the camera's electronics to balance the light out to make that card neutral. You can do the same thing with a white or gray card and custom white balance in your camera.
Unfortunately, camera manufacturers do not have a standard way of setting custom white balance. While the principle is the same (make something white or gray neutral) from camera to camera, the specifics are different, so I can’t tell you exactly how to do this. You must check your manual. Once you have done a custom white balance, you can keep the camera set to that as you continue to photograph in that same light. When the light changes, you need to perform another white balance.
This is a critical issue to me and to much of my work. When I was editor of Outdoor Photographer and PCPhoto magazines, I used to spend a lot of time with the art directors looking at proofs of pages to see where photos were on or off color.
Now when I submit images to publications and for books, I don’t want the folks there to have to do much work (publication folk tend to be overworked these days). And I want them to know that if there is a color cast in the image, it belongs there. I find that it is impossible to have this degree of control over the image if I shoot AWB, plus it always makes more work for me in the computer.
Bottomline: Don't rely on automatic white balance. Explore other built-in setting and custom setting options to optimize white balance for "the look and feel" of your scene -- in the camera.
- Rob Sheppard
0 comments:
Post a Comment