I don’t actually use this much these days, but it’s a handy option to have, especially in difficult to gauge situations. Setting white balance is easy; it’s as easy as taking a snapshot. Using it appropriately is tougher.
Setting white balance: go into the menu, like we did yesterday. This time, go to the far-right option (looks like a couple of triangles and a dot). Immediately, you’ll start seeing funny things going on, like in the pic to the right. That’s the custom white balance screen evaluating the balance based on… a black piece of paper. To set this as the white balance point, do what it says: press the MENU button.
So yeah, it’s easy to set white balance. but what should you use? Well, something white. Or non-tinted, at least – grey technically works pretty well, so long as it’s a dead gray. Snow works, so long as it isn’t yellow (and for us in Anchorage, so long as it isn’t break-up). Walls sometimes work – I’ve found decent results using grey construction blocks and the interior walls of my house (we painted it an almost flat white). Shoot, after a long winter in Alaska, I’m so pasty I can even use the back of my hand and get decent results.
These are all techniques that work in a pinch, but it’s better to use a real white balance card or something similar to get it right. When travelling, I usually carry a card with me. Running around town? Not at all. That’s why I rely on presets with the sd500.
What about my SLR? I usually use kelvin. That’s not an option on the sd500.