I've read a lot about WB, but am a little confused.
In this article
Introduction to White Balance it talks about using a white or grey card.
1. Does it matter if it's white or greay?
2. The really confusing part is where it's held up to the camera to tell it what colour is white. Are you taking a shot of the card and using those readings to set your WB before recomposing and taking the shot?
3. What is considered neutral grey? Would that be halfway between darkest and lightest grey?
Thanks for any and all help with this.
Cheers