White balance
Film users have no control over white balance. You buy a film balanced for typical daylight, and the only other option is to switch to a special ‘tungsten-balanced’ film for shooting under studio tungsten lighting. Digital cameras, however, can compensate for different-coloured lighting by altering the ratios of red, green and blue as the image is processed and saved. Alternatively, if you have a camera that can save RAW files, you can choose the white balance setting when processing the image on your computer. By default, digital cameras adjust the white balance automatically, but there will be situations in which you might want to override this automatic setting and choose the white balance manually, in order to preserve the colours of the scene, or to make sure that the colour compensation is correct.Quality issues Although you can change the white balance of your images later in your image-editor, it’s not necessarily the best time to do it. If you save your images as JPEG files when you shoot, the camera processes the sensor information before saving the file, and this processing will include white balance adjustment – the camera applies whatever white balance value is currently set. If you then go on to alter the colour balance on your computer, you’re in effect processing the image a second time, which introduces a degree of quality loss. It’s best to do one of two things: either set the correct white balance setting at the time of shooting, or shoot RAW (unprocessed) files and process them on your computer, choosing the white balance setting at that stage. | | Preset white balance |
 | | Auto white balance |
Auto vs preset You shouldn’t leave your camera set to auto white balance permanently, because it won’t always get it right. The camera will attempt to analyse the colours in the scene and ‘normalise’ them, but it can often fail to differentiate between the colour of the light and the intrinsic colours in the subject itself. In addition to this, it may attempt to compensate for atmospheric lighting conditions that are actually part of what you’re trying to record. Finally, where you do want to ‘normalise’ the colours, you’ll find that auto white balance systems often fail to compensate for extremes of lighting, such as the excessive warmth of domestic tungsten lighting or the pronounced ‘coldness’ of the light in deep shade. You may find it better to choose your white balance settings manually to suit the conditions, because at least then you’ll know how the camera is going to respond.Auto white balance systems aren’t infallible. They’ll often fail to correct adequately for shady conditions, leaving images with a cold, bluish tinge. Choosing the right white balance preset produces warmer, more realistic-looking colours. Warming things up Most people prefer shots to be ‘warmer’ rather than ‘colder’. Indeed, landscapes and portraits often benefit from a little extra warmth, rather than being rendered with technically ‘correct’ colours. There are a few ways of achieving this. One is to deliberately choose a mismatched white balance setting designed for cooler-toned lighting. For example, to warm up a sunset, try setting the white balance to Cloudy or Shade; this fools the camera into warming up the colour balance. You could also use a warm-up filter attached to the lens, but make sure you choose a manual white balance setting – if you leave it set to auto, the camera may attempt to compensate for the filter, leaving you back where you started. You can also warm up images once they’re on your computer, and the easiest way to do this is by adjusting the colour balance; try adding red and reducing blue in roughly equal quantities. | | Sunsets can prove disappointing
if you leave your camera’s white balance set to auto. The camera may attempt to correct for what it sees
as an excessively ‘warm’ colour temperature, leaving you with a rather dead and colourless image. |
 | | By switching the balance to the Cloudy setting(even though it,s not actually cloudy),you're telling camera to 'warm up' the colours(as if it is cloudy.This intensifies the yellows,oranges and red colours of sunsets very effectively. |
Getting creative You can add more extreme colour shifts in Photoshop to great creative effect. For example, to simulate moonlight, first darken the image to give a night-time effect, then shift the colour balance drastically towards blue. (Incidentally, moonlight isn’t actually blue. It’s as blue as daylight, but the artificial effect creates the impression of moonlight that we’ve all absorbed from countless Hollywood films.) Sunsets can often prove disappointing, largely due to the camera’s attempts to neutralise the colours. One way of restoring a sunset effect is to apply a coloured gradient to your image. You can do this on another layer, using the Multiply or Color blending modes so that the gradient overlays the image below, rather than covering it up. Why not experiment at the time of shooting, by choosing white balance settings that are completely ‘wrong’ for the conditions? We’ve mentioned the idea of shooting sunsets using the Cloudy/Shade setting, but try shooting daylight portraits using your camera’s Tungsten setting for an eerie, cold blue tone.
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