Telephoto Lens Cap for Canon & Nikon Camera Lenses

TECHNIQUE – Top 5 Tips for Quality Image Files (part 5)


This is one piece of advice that most pro nature photographers won’t give you because RAW files do offer you the ability to change white balance in the computer without degrading the image. There are three reasons that I urge you to set your desired white balance in the field, two of which are perhaps a bit capricious but one that has technical importance.

Before I get to the reasons, let’s take a quick look at what white balance means. Every kind of light has a color temperature, which is actually expressed in degrees Kelvin. The light outside on a sunny day is somewhere around 5000 to 5500 degrees Kelvin. For our purposes, we can consider this to be a neutral light. A tungsten light bulb, on the other hand, has a color temperature of around 3000 degrees Kelvin. This is a relatively “warm” light. The light on a cloudy day, especially at higher elevations will have a higher color temperature, say somewhere between 6000 and 7000 degrees Kelvin. This is cool light.

Back in the film days, most films were daylight-balanced, meaning that they were set to record things at a sunny day white balance. Thus, if you used this film to photograph a wedding hall lit by tungsten light bulbs, the resulting images would have an orange color cast. This can be a nice look but if photographers didn’t want it, they would use a blue filter over the lens to increase the color temperature of the light entering through the lens, thus resulting in a more neutral-looking image. By the same token, nature photographers shooting landscapes on a cloudy day in the mountains would often use a warming filter. These amber/orange-colored filters made the cool, bluish light warmer, resulting in a more natural-looking image.

Today’s DSLR cameras handle these issues through the use of white balance settings. You’ll notice that there are a number of presets for tungsten, flourescent, daylight, cloudy, and flash (among others). These presets simply tell the camera to record a given scene at the color temperature that corresponds to each preset’s value. So, daylight white balance on most cameras will be around 5500 degrees Kelvin, cloudy around 6500 Kelvin, and tungsten around 3000 Kelvin. So, if you shoot a daylight beach scene using the tungsten white balance setting, you can get a bluish, moonlit kind of look. Alternatively, you can punch up the colors of a rather cool and anemic sunset by setting your camera on cloudy white balance to bring out more yellows and reds. Of course, you can also set the color temperature manually on most cameras. So, if one of the presets doesn’t work, you can set the camera to record at 2200 Kelvin or 5700 or 9800 — anywhere between 0 and 10,000.

Many people, even many pro photographers (!), use auto white balance, in which the camera tries to evaluate the light and make the best judgement on color temperature. I never use auto white balance for nature as it nearly invariably gives an unattractive bluish/gray look. Others are fans of custom white balance but setting a custom white balance is a cumbersome chore and is best suited, in my opinion, to studio work.

white balanceAbove is a comparison of how different white balance settings affected my image of a chestnut- mandibled toucan. My original choice was daylight, which I still think is the best. Cloudy is too warm for this scene, and tungsten obviously is absurdly cool. Auto white balance, which is how many people shoot, doesn’t look bad but it’s too gray and cool. Daylight brings the muted green colors of the background and the bright yellow colors on the toucan the closest to how the scene actually was when I took the picture.

Still, auto white balance did a respectable job and, as we’ve been discussing, having shot in RAW would mean that I easily could adjust the white balance in post-processing. So, why worry about setting the white balance in-camera? Why not just use auto as it’s one thing we don’t have to worry about in the field? Here are my three reason for why I think it’s important to set your preferred white balance in-camera.

First, I consider it one of those things that keeps you in the zone as you’re photographing. I’m much more satisfied with my effort if I’ve considered every photographic variable in the field. Not convinced?

Second, I just don’t enjoy looking at auto white balance images on my screen. They look strange, and I have a hard time evaluating if I’m getting what I want. Better, but not quite?

Ok, here’s the third and most important reason. You’re shooting RAW. You know how to interpret your histogram. And you’re exposing to the right. You’re doing everything to get the maximum possible image file quality. The problem is that the histogram is derived from a JPEG. That’s right, even though you’re shooting in RAW format, your camera needs to interpret that data into something you can see, which is the little image on the screen on the back of the camera.

This little image is a processed JPEG that takes into account things such as white balance. The histogram is derived from this little processed JPEG, which means that if you shoot in auto white balance even though you know that’s not the look you’re going to want, the histogram is not accurate. You may be clipping highlights or blocking up shadows sooner or later than what the RAW data show because you are evaluating an auto white balance JPEG.

Let’s take a look at the figure below. This is my toucan shot, with my preferred daylight white balance on the left and auto white balance on the right. The difference is subtle but you can see that auto white balance is actually showing us a brighter histogram. Most values are shifted slightly to the right. This is especially apparent when we consider blown highlights, which is crucial because in this image I wanted to push my exposure as far to the right as possible in order to bring out feather detail in the toucan’s black feathers.

Pay attention to the tuft of white feathers just above the toucan’s tail. Do you notice the bright red areas? Those aren’t on the toucan but rather are blown highlight indicators from Lightroom. I have just a couple of blown spots in the daylight white balance version but quite a bit in the auto white balance version. Though I want to bring out feather detail in the blacks, I’m also very concerned about blowing out the whites.

white balanceHad I evaluated the auto white balance histogram in the field, I would have thought “Man, the whites are really starting to blow out. I’d better back off a bit on my exposure.” That would have been a mistake because I wanted the colors that daylight white balance would produce and by evaluating that histogram, I can see that I’m fine — a couple of slightly blown highlights in those white feathers but nothing that can’t be

dealt with in Lightroom. Had I backed off on my exposure as the auto white balance histogram was indicating to me, I would have blocked up the dark tones a bit, robbing me of some fine feather detail in the black feathers. I would have ended up lightening the black a bit in post-processing, and this probably would have introduced some noise.

Am I making a mountain out of a molehill? Perhaps, but remember that it’s a competitive world out there, and I want to make sure that I produce the cleanest files possible so that the images I send to magazines are as good as they can be. And I want my fine art prints to be beautiful and full of detail. In a competitive business, every edge that you can give yourself counts. Many photo buyers are quite discerning, and I want them to know that I’m going the extra mile.

By the way, not only does the little JPEG on the back of your camera (and the resulting histogram) take into account white balance but also variables related to picture style. Setting picture style to Vivid in Nikon or Landscape in Canon tends to produce snappy, saturated files that look great on the back of your camera. But if you have sharpening (which increases edge contrast), contrast, and saturation set high, you might think that you are clipping highlights or shadows when in fact the RAW data (which don’t have a white balance or picture style encoded in them) have more latitude than what the histogram is showing you. That’s why most pro nature photographers will have their picture style setting set to neutral or faithful so that their histograms are more representative of the RAW image data.

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About the author Gregory Basco
Like many nature photographers, I started my career doing something else. A political scientist by training, my research focused on the politics of the environment in Latin America. I researched environmental politics and ecotourism in Costa Rica and worked here for a number of years as a conservation professional, having first come to the country in 1992 as a Peace Corps volunteer. I now dedicate myself full-time to my own photography and my Costa Rica photo tour company. I work out of my home office in Costa Rica’s central highlands, where I live with my wife, twin boys, our dogs and cats, and various hummingbirds and songbirds that visit our backyard feeders. Visit Greg’s galleries, store, and workshops at Deep Green Photography.

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