Photography Explained: White Balance
As your photography skills increase, you'll start investigating some of the settings on your camera you might have parked for a while. When I first played around with white balance I remember thinking something along the lines of 'That's cool. There's an option that makes the picture kind of orangey, another one that makes it look bluer... you know what, I think I'll just leave that on auto for now and come back to it later.'
It's just as well I did come back to it because white balance is an important attribute of an image. So what is it exactly? To start with, think of it as a measure of how white a white object actually looks in a photo. Ok, but why would it look anything other than white? To answer that we need a quick explanation of different light sources.
We see natural and artificial light. Natural light comes from the sun of course, but sunny days look different to cloudy ones and there's an obvious difference between the light you experience during a sunrise and at midday when the sun is at its highest point.
When you turn on a lamp or a torch you're creating artificial light but the effect it has on a room is dependent on the source. Think of the difference between the lighting in your living room and a supermarket for example. Different light sources create their own characteristic colour casts.
A fluffy white bunny sitting outside on a cloudy day looks just as white when you bring him into an artificially lit room. You don't perceive any difference when you look at him under these different lighting conditions because your brain reinterprets what your eyes see, making Flopsy appear perfectly white regardless of the light source.
But if you take his photo in these two scenarios you will see a difference - the light's colour cast will be evident. Cameras can't do what your brain does on their own. They need to be told how to remove the colour cast by setting the white balance.
By choosing a white balance, you're instructing the camera how to make white objects actually look white in a photo taken under the current lighting conditions. From there it's able render every other colour accurately. The colour cast is removed and the result looks natural. So how do you know which setting to go for?
The colour cast is determined by the temperature of the light. Hang on a second, light has a temperature? That seems a bit abstract because it's not something you can feel like the temperature of water. But in a way you can feel it.
Remember the last time you were thinking about what colour to paint a room? You might have thought that blue would make it feel cold whereas yellow would give it a warmer, cosier feel. That's because the light reflecting from your freshly painted walls has a temperature property. Warmer light, for example during a sunrise, is more yellow/orange. Cooler light, such as on a cloudy day, is bluer.
A colour cast is not necessarily a bad thing but you usually want rid of it because even if it doesn't ruin your photo, it can alter its ambiance, making the scene look warmer or cooler than natural. The effect is particularly noticeable on plain buildings and walls as demonstrated in the next three images.
So now it's time to look at the actual settings. As well as Auto, your camera should have the customary white balance options:
- Incandescent (or Tungsten)
- Fluorescent
- Flash
- Daylight (or Sunny)
- Cloudy
- Shady
The idea is to pick the setting that most closely matches the shooting conditions.
Daylight, Cloudy and Shady are the natural light settings and they get progressively cooler. On a foggy day the light has a bluish tone so a cool setting is required to avoid a blue tinted image. Shady would probably work best. For a sunset when the light is much warmer, try daylight.
Incandescent, Fluorescent and Flash are types of artificial light. Incandescent is the warmest and comes from the majority of normal lightbulbs in your house. Fluorescent lighting, cooler than incandescent but generally warmer than daylight, is common in offices and department stores. When you're taking pictures in your living room, incandescent is a good bet if there's a lamp switched on.
Here's where I dispense one of my most profound pieces of photography advice. Auto white balance will very often do a perfectly good job. If you're following a similar learning curve as I did, you'll finally get your head around white balance then leave it on auto anyway. Just be aware that on this setting the camera will attempt to create a neutral colour balance and you won't always thank it for that.
If you get up at 5am to photograph the sunrise, you certainly don't want to neutralise the characteristic red and orange colours in the sky. That's one situation where I'd definitely emphasise them using the daylight or cloudy setting for a warmer tone.
And it gets better because there's a part two to my profound advice. Even if the picture doesn't turn out quite right using auto, or indeed any other setting, it's very easy to correct in post-processing as long as you've used a certain file type. I'll talk about that in the bonus section of this tutorial.
So does that mean there's not much point to this tutorial? I wouldn't say that. There are some situations where you'll want to give white balance a second thought and at least experiment with the different settings.
As the day ends and it begins to get dark, street lights turn on, roads are filled with headlights, buildings become illuminated, neon signs start campaigning for your attention. Scenes are awash with different types and intensities of artificial light, making it difficult to decide which white balance to use. So try them all. Even a setting you might think is inappropriate could result in a cool creative effect.
Photography literally means 'writing light' and with endless creative possibilities on offer, this time of day presents the perfect opportunity to experiment with different ways of capturing the same scene.
Bonus Section: Shooting in RAW
Digital images come in many formats, the most familiar to photographers being .jpg. Jpgs provide the best compromise between file size and quality; if you print one to hang in the living room, the quality will stand up well enough to close inspection despite the files still being small enough to load quickly on a website.
All cameras I know of save images as .jpgs. However this format doesn't retain 100% of the data collected by the camera because there's too much of it. Once an image is captured, the camera's software compresses the data recorded by the sensor, making sophisticated decisions on what to keep and what to throw away. Then it presents you with a lovely .jpg.
The results are usually very good but they're still the camera's choice, not yours. Who's to say you couldn't have created a better version if you had access to all the original data? Furthermore, .jpg is an example of a lossy format which means whenever you reopen, edit and save an image on your computer, data is gradually lost, causing the image quality to deteriorate.
Happily you do have access to all the original, uncompressed data as long as your camera has the option to save it in a RAW file. All DSLR cameras and a lot of the latest compacts have this capability. To use it, look for the Image Quality or Image Size option in the menu. As well as the Basic, Normal and Fine (or Small, Medium and Large) options, there'll be one called something like RAW + JPEG.
If you have this setting, I'd recommend selecting and permanently sticking with it. Even if you're just taking a bunch of test shots, you never know when it might be handy to have a RAW file in your pocket because there's so much extra data to play with. Of course you pay for that with the additional storage space needed, but I don't see that as a drawback. Just make sure you have plenty of spare memory cards.
RAW isn't a file format in the same way .jpg is. It's more a file type because it hasn't been standardised into one format yet. Nikon, Canon and Sony use different variants but they all require some degree of post-processing. The good news is most software packages that work with RAW files are compatible with all types. The bad news is you have to buy one of these packages so you'll need to decide whether it's worth the hit on your shiny new telephoto lens savings fund.
When working with RAW images you never alter the original file. It's a non-destructive process. Your changes are previewed as you apply them but you're only building up a list of edit instructions, without modifying the original data or losing any quality. Once you're done, you export the results as a new .jpg. Instead of editing the .jpg you can go back to the original RAW image again and again to start over or add new adjustments, exporting as many .jpg versions as you want.
I think a RAW editing package is definitely a worthwhile purchase. The main player is Adobe Lightroom which is available for Mac and PC. You can either buy it outright or subscribe - it's also possible to get a combined Photoshop and Lightroom subscription. Check out Adobe's website for the deals. Photoshop comes with a plugin called Camera RAW so if you have that you're already good to go. Camera manufactures also have their own free software which you can download. Nikon's for example is Capture NX-D.
To end this bonus section I'll quickly describe how to change white balance in Lightroom. This is so easy and effective, it's the reason photographers increasingly leave their camera setting on auto.
Once you've imported an image, go into the Develop module and look for the Basic menu which should be the first one in the list. At the top of that section are the WB sliders, one for temperature and one for tint. It's no coincidence this is the first editing option you come across. Simply adjust them until any unwanted colour cast fades away or is replaced by what you were aiming for when you took the shot. You can also choose a preset from the dropdown options above the sliders.
