White Balance

[MarkP]

How often do you need to reset the white balance? If I move around a room that has different lighting conditions do I need to reset it each time the lighting changes?

Thanks.

[BBPhoto]

Mark - If you are talking about a custom white balance when you refer to a white balance 'reset', it really depends. If the 'different lighting conditions' you speak of are a different type of light source, then yes. That is, if you take a custom white balance in an area of the room where the subject is being lit with light coming in from the window, the light temperature might be very different in another part of the room where subject may be lit by overhead fluorescent or tungsten lighting. In this case, it would be prudent to do another calibration.

If the 'different lighting conditions' are varying intensities of the same light source, then you should be OK with a single custom setting. You can look at a custom white balance much the same way you look at the factory settings on your camera (i.e. sunny, cloudy, etc.). You try to match the factory setting to the actual light source. If it's cloudy outside, its the same setting for all your shots. If you go inside... time to change the setting.

A note on WB, if you aren't already aware, is that when calibrating a WB setting you are balancing for the white and not to it. I have found it best to take a custom WB reading off of an 18% grey card. Alternately, you could always shoot in RAW mode where you can change the white balance in post processing.

I hope this answers your question.

[SpecialK]

When the color of the light changes to one that is outside of the current camera setting is when you adjust the WB.

If, for instance, you are "moving around a room" that is only illuminated by window light, even though the exposure may change, the WB does not.

If you close the curtains and turn on the tungsten lights, the WB will change, Your camera should now be set for "tungsten" light if that is an option or AWB, or a custom WB setting if you feel critical about it.