Photography News Issue 61

Photography News | Issue 61 | photographynews.co.uk

Technique 75

Camera School Camera School has been going since the very first issue of PN so it is taking a break. We finish this series with a look at how you can use white-balance to get colour-perfect shots, but also how you can get creative

AWB

4000K

Above The camera’s AWB was accurate and gave this snowy twilight scene an attractive cool hue. Setting a lower K value (4000K in this case) produced a much more blue picture with a stronger, colder mood. With scenes like this, there is no real right or wrong – it simply depends on the mood that you want to evoke in your shots.

colour temperature, the lower the value the warmer the light and the higher the value the more blue the light. Typical, neutral daylight is 5000-5500K, candlelight which is very orange might be 2000K while reflected light from a blue sky is around 10,000K. USINGWB The camera’s AWB feature is very good at dealingwith different lighting types but it is far from infallible and performance can vary from model to model too. Take pictures in typical domestic lighting and they can look orange; take shots in fluorescent strip lighting and they can look green; use the camera in shade and the results can look blue. Digital cameras have white-balance presets so if you find that the AWB is not giving a satisfactory result, the option is to use the appropriate preset. Presets on most cameras usually include shade, cloudy day, fluorescent lighting, electronic flash and tungsten lamps,

usually denoted by icons – a cloud for cloudy day, a ‘millipede’ for fluorescent lighting, a lightning bolt for flash and a bulb for tungsten are almost universally used examples. CUSTOM PRESETS But camera white-balance features have even more chances to fine-tune the result. There is the option of custom preset where you can set the correct balance very accurately for the lighting you’re shooting under. Different cameras work in different ways to do this and all you need is a sheet of white paper or piece of grey card. Hold the paper/ card in the same light as that being received by the subject, fill the frame and take a shot. On Nikons, taking a custom reading does not take a picture but just takes a reading. On Canons, you take an actual picture that you can select as your neutral target. If you want colour-accurate pictures, taking a custom WB reading is recommended but do

remember that you’ve set the camera up for that particular situation or lighting type. Changing lights or putting the subject in a different light means that custom reading no longer applies so you need to do another custom reading or go back to AWB. USING K There is another option available in most cameras and that is using the Kelvin or K feature – this is usually an option along with the other white-balance settings. The K feature works within a range, typically from 2500K to 10,000K and you directly influence the colour of the picture bymanually selecting a value. Experience will help you decide which value to set so you need to experiment with different values in different lighting types. The cool thing is that with electronic viewfinders and live view monitors you can enjoy a real-time preview of the effect and you can adjust the K value until you get a look that you like. As a guide, setting a lower Kvaluemeans the image looks cooler andmore blue, while setting a high K value makes the picture appear much more orange and warmer. How you use the power of the K white- balance setting depends on what you want to achieve from your picture. You could, for example, make a cold wintry scene even more cool-looking or if you want a very warm portrait, that is perfectly easy too. THE FINAL OPTION There is another way of working with creative white-balance control and that is if you shoot your pictures in Raw format. If you shoot JPEG format youneed to get the effect right in-camera because there is not much you can do with the files produced. In Raw format, however, you can tinker with an image’s white-balance after the fact, so if you have existing pictures in the Raw format you can use your image-editing software to adjust white-balance.

Words & pictures byWill Cheung

The white-balance control of your camera is a very powerful feature and most us probably take it for granted, leaving the feature set to auto white-balance (AWB) delegating the responsibility of colour control to the camera. There’s nothing wrong in that at all because theAWB feature is usually very effective and so sophisticated it can deliver neutral results in all sorts of lighting types. It assesses the light in the scene and does its best to give a natural-looking result so a white subject comes out looking white. The human brain does a similar job and very effective it is too, keeping white subjects looking white in all sorts of different lighting. Most of us are probably unaware of it but the colour of light changes all the time depending on the time of day and the type of lighting. The colour of light is measured in Kelvin or K and without wishing to dig into the science of

AWB

3200K

8000K

Images Use Raw format and you can play with white-balance to your heart’s content during processing, and because it’s a Raw file the original stays untouched whatever you do to it. Expressed another way, Raw processing is non destructive.

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