So now that we covered the basics of aperture, shutter speed and iso, it’s time to move on to the white balance.
Colour of light
White balance is often a tricky part of photography. It has to do with the colour of the light. Every light source, including daylight, has its own colour temperature. Colour temperature is measured in degrees Kelvin. Daylight is usually around 5000 to 5500 degrees Kelvin, but can vary depending on the time of day and conditions. For example, shadows often have a blue glow, as do early mornings when the light is just starting to come up. At the end of the day, the light first turns yellow (the golden sunset!) and as the sun sets, the light turns blue again.
Who doesn’t know the phenomenon of taking a picture by candlelight without a flash? This creates a huge yellow glow over your photo. The same goes for a photo taken under the light of an incandescent bulb or the green light of a fluorescent tube. And where candlelight can still create a nice atmosphere, the light from a fluorescent tube is rarely beautiful.
A flash (which is about 5500K in colour temperature) has the effect of removing the glow of artificial light and then making the colour look neutral – to the eye.
When we look at a white sheet of paper under the light of an incandescent bulb, it looks white. Our brains register and correct many times better than the software in your camera will ever be able to. That’s why sometimes you need to give your camera a hand. To get a neutral colour, you sometimes need to correct the white balance. This can be done afterwards in software or while shooting with the white balance settings.
White balance is often tricky in a restaurant. On the left is the photo as it came out of the camera, and on the right is the photo after correction in Lightroom.
Presets
Your camera comes with a number of default presets. You can find them in the settings menu and often via a dedicated button on the back of your camera. This varies from camera to camera, so check your manual. Presets include AWB (auto white balance), daylight, shade, sun, TL1 and TL2, tungsten and halogen. There is usually also a manual white balance setting.
If you are shooting under tungsten light, you might assume that your camera will correct to make the photo neutral. This doesn’t always work, however, as light bulbs can have different shades, so your photo will be the wrong colour anyway.
Manual white balance
In this case, it is usually better to set your camera to manual white balance. The setting varies from camera to camera, but basically you take a picture of a white sheet of paper in exactly the same lighting conditions as you will later take the photo (make sure there is nothing else in the picture but the sheet of paper!) You then set your camera to manual white balance and select the photo of the white sheet of paper. By doing this, you are telling the camera that you want your photo to be white. Your camera will then correct the white balance to ensure that subsequent photos are neutral in colour.
Lighting conditions can change quickly
In reality, working with manual white balance can be tricky, for example because lighting conditions can change quickly. This can mean that you have to check each photo to make sure your white balance is still correct. This doesn’t allow you to react quickly.
It is easier to correct the white balance in software (provided you shoot in RAW!). I always shoot in AWB (automatic white balance) mode. Whether I am shooting outdoors, indoors or under a fluorescent light. The most important thing for me is to avoid having multiple light sources in one photo. For example, if you take a photo in a shop in daylight, you will notice that you can correct the colour in the shop, but the light coming in from outside (daylight) will turn horribly blue. This is because you can only correct your photo for one type of colour at a time. Photographing with mixed light sources is therefore guaranteed to go wrong.
Shoot in raw!
Fortunately, you can easily correct the colour in RAW. Under difficult circumstances, I always shoot with a grey card to check. First, I make the setup I want to use, take a photo of the setup with the grey card, and then start shooting.
A grey card is a card made of cardboard or plastic with a calibrated shade of grey. Also called medium grey. Since both the software and your camera are set to recognise this medium grey, you can use a grey card as a reference to correct your colour.
When I get the photos into Lightroom, I take the photo with the grey card as a starting point and use the eyedropper in the Developer module to indicate what the grey card is. As soon as I click on the grey card, Lightroom automatically corrects the white balance so that the grey card is mid grey. I can then copy and paste this setting into subsequent photos. This is an easy way to make sure your photos have the right colour settings.
The photo on the left is before white balance correction and the photo on the right is after white balance correction (and minor exposure correction).
Did you forget to shoot the grey card and then find out that the white balance was wrong? You can often use a grey or white object in your photo to correct the colour. In the example of the photo above, I used the fork to change the white balance. In this case, hover over the fork with the eyedropper until you get a colour close to mid-grey. Click on it and you will see that the colour is adjusted immediately. Smaller corrections can be made using the sliders.