What have you used when shooting at an outdoor stadium, when the lights are also on for supplemental lighting? When I try auto, it seems too cool, but none of the other preset values seemed to work well, either. I did some color correcting in Aperture to get a result I liked, which seemed to be right around 4000K. Can I translate this to a 'custom' WB in-camera then?
Camera is Canon 5D mark III. I don't have any of the tools like a lens-sock/cap to shoot a custom WB frame as I don't do this kind of shooting too often and until now the presets have all been satisfactory for my needs. The time of day was twilight (clear sky), moving through sunset then into darkness where the predominant source of light was the stadium lamps.
Also, are these usually mercury vapor lights? Obviously they're not high-pressure sodium as they don't have the orange tint.
Thanks to all for your help!
Most sporting events now use metal halide lamps
. As shown here
, they come in various CCTs. Another problem is the ballast used to power these lamps. Magnetic ballasts have a 60 hz flicker so their appearance at high shutter speeds can vary. Electronic ballasts drive the lamps at much higher frequencies and produce more uniform results. To test the temporal uniformity of the light you can take a burst of shots at a high shutter speed from a WB card and compare the color results.
Taking a white balance from a gray or white card can be problematic if you are in the stands and do not have access to the lighting on the field, in which case some type of integrating device (such as an Expodisc) over the camera lens could be employed.
You don't state if you are shooting JPEG or raw. The latter is preferred whenever there could be white balance problems, since the WB can be adjusted later with no loss of quality. Many sports shooters do use JPEG due to their high volume of shooting, so it is important in this case to get the WB in the camera right. If you do shoot raw, the files can be batched processed while you have coffee or go to bed, but this won't do if tight deadlines are present.