Getting it white
- — 01 June, 2006 11:44
Despite your best efforts to shoot good footage from the outset, you can often be let down by your camcorder, or even the situation itself. You don't always have time to configure elements such as lighting and camcorder settings optimally if you want to catch a family moment before it's over - nor would your family appreciate the faffing about, in any case. The end result will sometimes be video that needs a bit of work before you can even think about moving on to editing and special effects pizzazz.
Colour inaccuracy is a common problem with footage shot in an ad-hoc way. Taking the time to set your camcorder's white balance (sometimes described as colour temperature) can avoid excessively blue or yellow tones created by artificial lighting, but you still can't be sure your camcorder will give you a consistent look across varying lighting conditions (see Figure 1).
There will be many occasions when you simply don't have time for manual setup, and automatic white balance has improved considerably over the years. However, if things go wrong in this respect, software can often help you considerably.
Virtually all editing applications have some form of colour adjustment filter. At the most basic level, you'll be able to tweak red, green and blue channels manually. Ulead VideoStudio 9.0, for example, offers this level of control (see Figure 2), while the same company's higher-end Media Studio Pro 8.0 gives you more detailed histogram views and control over highlights, mid-tones and shadows.
However, getting colours right using either method is a matter of trial and error. You'll have to keep fiddling with settings until things look right. It works, but can be laborious.
Getting the point
Colour correction can be made a lot easier than this, though, by using a single reference point. This is usually white, but black is also used in professional circles. The method works on the principle that if you know something in the frame is supposed to be white, the software filter can adjust the full chromatic range accordingly.
Some software will pick this out for you automatically - in particular, Adobe Premiere Elements 2.0. This program has some manual image control ability, which you can access without even applying a filter - the Properties panel gives direct access to hue, saturation, brightness and contrast controls. But to fix really dire colour, the Auto Levels filter will be much easier and more effective - see Figure 3.
