Canon White Balance Isn't Consistent

[eboyer7]

Hi. I have a Canon A720 IS and I was recently photographing a 360 by 180 degree panorama of a room in my house, so of course I set my camera to full manual control to make sure the exposure, aperture, white balance, etc are the same for every picture. The panorama turned out pretty good, except for the white balance. Even though I had set the white balance to "Tungsten", the white balance was moderately different from one picture to the next. Anyone know why this happened? Shouldn't the Tungsten setting (or any other white balance setting) set the white balance to a fixed value and not change from one image to the next?

After discovering this problem I instead used the custom white balance setting and, thankfully, every image had exactly the same white balance. So, I guess I'll be using custom white balance for now on when I need photos to have exactly the same white balance.

If anyone wants to see sample photos then I could upload them, but if you have a similar Canon then you can probably see this effect by setting the camera to a particular white balance and moving the camera from areas of very different lighting and colour (for example, I went from a bright, light blue area to a dark brown area and saw the white balance changing).

-Eric

 

[CraniumDesigns]

just shoot everything in raw and set the WB in post processing.

 

[CxThree]

I think you answered your own question. When you moved to different variables, the camera had to make a new estimation to select the white balance. If you want it to be more consistent, you need to set it manually. When I shoot at a location, I rarely set my WB to automatic. I pull out a gray card and have someone hold it at a little bit of an angle so it catches the light from above. I take a full frame picture of that card and use it to set my custom WB. I then use that setting for my shots with that lighting. If you allow the camera to make all the decisions, it will get some right and some wrong.

 

[Dao]

I agree. Even inside the same room, lights that arrive at the camera sensor maybe different. Wall color, shadow, light reflected from other objects etc.

 

[Big Mike]

just shoot everything in raw and set the WB in post processing.

The A720 doesn't record RAW.

 

[eboyer7]

The A720 doesn't record RAW.

That's true, although with the CHDK hack (which I have) it can shoot raw. But, I have no use for raw and don't want to deal with all the necessary post processing to use it, so I'm not going to bother.

Looks like I'll just stick to custom white balances. I still find it weird that "Tungsten" or "Daylight" or any of the other white balance settings aren't absolute (they change from one scene to the next). The way I see it those settings should have a particular colour setting that doesn't change, no matter the scene. But, maybe it wouldn't look as good that way.