Photo Help-Again-Updated

Are you using the Custom White Balance function of the camera?

Here's how it works. You set lighting, camera and everything up just like you will to shoot the coin. If you shoot tethered to the computer, don't tether it yet. Put a piece (or a few pieces, so the background doesn't come through) of white paper where the coin will be. The paper needs to fill the whole viewfinder.

Take a shot of it, onto the memory card of the camera. I hold a toothpick in the center of the frame, to give the camera something to focus on, and then remove the toothpick while holding the autofocus, before taking the shot. It's easiest if you currently don't have any other shots on the card. Current White Balance setting doesn't matter, because you're essentially going to tell the camera, "This is what white/grey looks like under this lighting," and the camera will know how to adjust.

Hit the Menu button, and arrow to the second icon from the left. The drop-down choices will include "Custom WB." Arrow down to it and hit Set; the viewfinder will start showing the pics you currently have on the card. Find the white/grey card shot you took and hit Set - it should ask you something to the effect of "Do you want to use this for Custom White Balance?" Tell it Yes, and from then on, it will use that example when you choose Custom for White Balance. As long as you do your lighting the very same way, each time, that setting will give you correct color.

I use either one, two or three identical halogen lights when shooting, and the same Custom setting works regardless of how many of them I use. If *anything* changes, even the angle of the sun (if any is getting into your shooting area), the Custom setting will no longer apply. For that reason, I usually shoot after dark.

I looked at the manual for his camera.

He's using a Canon T1i, the next generation after my XSi. The menu functions are essentially identical to mine, which is why I tailored my instructions so specifically.

I also tailored my advice, knowing the shortcomings of these particular cameras. They're notoriously weak with tungsten correction in both Auto and Tungsten WB settings, but extremely capable when using Custom. Although your advice concerning lighting of one color temperature is generally sound, I've found these Canon dSLR's (I've owned more than one in the series) to be quite capable of color-correcting with light sources of more than one type at the same time.