When it comes to white balancing, making white white is not always the best approach - though there are some situations in which in can be the target. Let me offer one example and may be point to some related ones.
If you shoot snow under a blue sky, especially if the snow is in shadow, the camera \"sees\" the snow as being quite blue. In fact, it can be essentially the same blue as the sky itself. However, when your eyes/brain literally see this scene in person, a more complex perceptual process takes place. Roughly speaking, your brain \"knows\" that snow is white, so despite the objective evidence that this snow is the color of a blue sky you still see it as white.
So you might think that simply color balancing to make the snow white would be the answer. However, if you try that you\'ll likely discover that the correction went to far and that truly white snow - despite what your brain told you above - looks phony. So what is the right \"white balance\" for the snow? This turns out to be a largely subjective issue. It is likely somwhere between the sky blue that the camera recorded and the pure white that we imagine snow to be. Here a \"correct\" white balance will simply look wrong.
To expand on this a bit. Let\'s say you photograph under a canopy of autumn leave because you like the effect of the warm coloration of the light. White balance that photograph and the very thing that attracted you to the light is removed from the image! Fail to make adjustments and the coloration in the photograph will seem more extreme that you perceived it to be while on location.
In your example of shooting under tungsten (or sodium vapor, or fluorescent, etc) light, you may well not want an \"accurately\" color balanced image. One thing we find attractive about subjects photographed under tungsten light is the warm quality it provides - i.e. we like the \"inaccurate\" color balance. If you color balance to the point that, once again, \"white is white,\" then that warmth is lost. Yes, in certain types of photography that could be desirable, but in many others \"correctly color balanced\" would be undesirable.
Again, it isn\'t about finding the one \"correct\" way to do this. It is about understanding principles about color balance along with principles about perception and also understanding how applying these principles can obtain the particular aesthetic outcome you are after.
The idea that perfect white balance is something to be desired in all photographs is unfortunate. Now I can think of some situations in which such accuracy is perhaps necessary - for example certain types of commercial, advertising, fashion, etc photography in which consistent and objectively \"correct\" color is more critical.
Dan
cgardner wrote: gdanmitchell wrote:
\"White balance\" here doesn\'t quite make sense to me. WB is only relevant when you shoot jpg, where the WB settings have a significant effect on color balance and alter it in ways that are only controllable in the most general sense. When you shoot raw you more or less get the sensor data without these color balance alterations. If you mean \"refine WB\" in the sense of making better guesses about how to set it automatically in jpg mode, why not? But the problem cannot really be completely solved since the camera can only make generalizations about the overall scene.
Regardless of shooting RAW or JPG tungsten light has less blue energy than daylight or flash and the light reflecting off a white surface into the RGB sensor sites has much less signal in blue.
To achieve WB - render the white object as white - in tungsten light the blue channel must be amplified more than R and G. For JPG that amplification occurs in the camera. In RAW it occurs when the RAW file is displayed on the computer — ACR or whatever RAW editor you use amplifies blue/yellow channel in the RAW file more than it would in a shot taken in daylight.
Given the same shot in RAW and JPG the RAW will look better because the conversion process is more sophisticated in ACR vs. the camera
When it comes to white balancing, making white white is not always the best approach - though there are some situations in which in can be the target. Let me offer one example and may be point to some related ones.
If you shoot snow under a blue sky, especially if the snow is in shadow, the camera \"sees\" the snow as being quite blue. In fact, it can be essentially the same blue as the sky itself. However, when your eyes/brain literally see this scene in person, a more complex perceptual process takes places. Roughly speaking, your brain \"knows\" that snow is white, so despite the objective evidence that this snow is the color of a blue sky you still see it as white.
So you might think that simply color balancing to make the snow white would be the answer. However, if you try that you\'ll likely discover that the correction went to far and that truly white snow - despite what your brain told you above - looks phony. So what is the right \"white balance\" for the snow? This turns out to be a largely subjective issue. It is likely somwhere between the sky blue that the camera recorded and the pure white that we imagine snow to be. Here a \"correct\" white balance will simply look wrong.
To expand on this a bit. Let\'s say you photograph under a canopy of autumn leave because you like the effect of the warm coloration of the light. White balance that photograph and the very thing that attracted you to the light is removed from the image! Fail to make adjustments and the coloration in the photograph will seem more extreme that you perceived it to be while on location.
In your example of shooting under tungsten (or sodium vapor, or fluorescent, etc) light, you may well not want an \"accurately\" color balanced image. One thing we find attractive about subjects photographed under tungsten light is the warm quality it provides - i.e. we like the \"inaccurate\" color balance. If you color balance to the point that, once again, \"white is white,\" then that warmth is lost. Yes, in certain types of photography that could be desirable, but in many others \"correctly color balanced\" would be undesirable.
Again, it isn\'t about finding the one \"correct\" way to do this. It is about understanding principles about color balance along with principles about perception and also understanding how applying these principles can obtain the particular aesthetic outcome you are after.
The idea that perfect white balance is something to be desired in all photographs is unfortunate. Now I can think of some situations in which such accuracy is perhaps necessary - for example certain types of commercial, advertising, fashion, etc photography in which consistent and objectively \"correct\" color is more critical.
Dan
cgardner wrote: gdanmitchell wrote:
\"White balance\" here doesn\'t quite make sense to me. WB is only relevant when you shoot jpg, where the WB settings have a significant effect on color balance and alter it in ways that are only controllable in the most general sense. When you shoot raw you more or less get the sensor data without these color balance alterations. If you mean \"refine WB\" in the sense of making better guesses about how to set it automatically in jpg mode, why not? But the problem cannot really be completely solved since the camera can only make generalizations about the overall scene.
Regardless of shooting RAW or JPG tungsten light has less blue energy than daylight or flash and the light reflecting off a white surface into the RGB sensor sites has much less signal in blue.
To achieve WB - render the white object as white - in tungsten light the blue channel must be amplified more than R and G. For JPG that amplification occurs in the camera. In RAW it occurs when the RAW file is displayed on the computer — ACR or whatever RAW editor you use amplifies blue/yellow channel in the RAW file more than it would in a shot taken in daylight.
Given the same shot in RAW and JPG the RAW will look better because the conversion process is more sophisticated in ACR vs. the camera
Nov 08, 2011 at 04:34 PM
Previous versions of gdanmitchell's message #10068582 « Canon's native ISO »
