Friday, July 28, 2006

Copying art - Colour Balancing

Balancing is probably a suitable word. It's a delicate balancing act and something that automatic modes on modern cameras can get wrong (although they do get it right very often). If you want certainty then you need to take some responsibility; which is a good thing, right?

If you are using film you have three options:

1. The film you buy and put in the camera is balanced either for daylight or tungsten.

Almost all film is daylight film so if you want to take images under tungsten light you may find it tough to find tungsten balanced film these days.

2. You can use a lens filter to correct the lighting to suit the film.

If you have tungsten lighting you need a filter to correct the yellow by using an 80B blue filter. If you are using fluorescent, green light, you will need a FL filter.

3. You can correct the light source to match each other and the film.

This is less likely when not in a studio with all the light sources being artificial and under your control. It is also useful to match different light sources to match each other.

If you are a digital user all three options still apply. However two new options become available (because digital is cool ok?)

4. Take a shot of a white (or grey) object and use it as a specimen for the camera to use for colour profiling. I like to use clouds in lanscapes as they are always 

This may be a calibration card, see your local camera stockist, or something you know to be white such as a piece of plain copy paper. Many pro-sumer and professional cameras will let you take a shot and specify it as the specimen for custom colour balancing.

5. As for option 4 but the colour correction is done in your computer afterward.

Photo editing packages such as Photoshop and Paintshop will allow you to remove colour cast by specifying an image as being white (or grey) and it will then balance other images using that colour profile.

Shooting in RAW mode on SLR cameras (and high end compacts) will require more colour control from you than when shooting JPEG or TIFF. This is because RAW has no colour information in it at all. It's 1's and 0's; your software for your computer needs to understand the RAW file format of your particular camera and it will also let you pick a colour profile or create one. This is where a shot of a calibration colour card is useful.

That's it, there is no more. Joke. It's very complex and once you get started you realise there is more to it. Practice makes perfect though so get out there and try some images and correct colour. Here's a hint. Blue sky is waaaaaaaaaaay too blue and images in shadow on sunlit days are totally wrong colour wise.

Remember if your lighting conditions change you have to re-calibrate. Your brain is brilliant at it but the camera is not so re-evaluate lighting regularly.