What you're looking for is the custom white balance feature on the EOS. I don't have an EOS, but this what I am presuming. On the D1X, I know it's a different brand, once I set my custom white balance and 'lock' it in, I can use over and over again. Although the D1X already has a 'tungsten' WB setting. Maybe the EOS has one too. Ask a Canon user or check out some Canon user group sites.