These numbers are standard ball-park guesses, a bit vague and arbitrary. Warm white fluorescent 3000В°K White Fluorescent 3700В°K 4000В°K 3800В°KД¬ool white fluorescent 4200В°K Day white fluorescent 5000В°K Direct Sunlight 5200В°K 5200В°K 5500В°KДaylight fluorescent 6500В°K High temp mercury vapor 7200В°K Shade (varies greatly) 8000В°K 7000В°K 7500В°K Sodium vapor lamps 2700В°K Incandescent / Tungsten 3000В°K 3200В°K 2850В°K The camera provides the following White Balance choices to match the color of the light in our photo scene. We learn that lowering White Balance Temperature makes the Color appear more warm. So we learn there are the two concepts, of Temperature, and of Color, which seem to run backwards of each other. Which seems very reasonable to us, however, science eventually learned that numeric Color Temperature of heated black bodies in physics is measured to run opposite, which while the 'color' blue may appear cool in art, but in physics, blue is instead a higher 'temperature' than red, which is a relatively cooler Temperature. Historically, the art world thinks of blue as a cool color (water and ice), and red and orange are warm colors (fire or Sun). These temperatures are used to describe the colors of light, and color is used to describe the temperature. The surface of our Sun is 5800В°K, which is between the red and blue, which we call White. Black body temperature can go much higher than red, to white, and then blue. Other sources like fluorescent lamps are not black bodies nor heated, but their color is described as the temperature of a black body that would generate the same color of light. Same idea for tungsten filaments of incandescent bulbs, and for our Sun. In the way that steel or lava becomes red hot at high temperature, their colors of red light are described by the temperature of the source radiator. In physics, color temperature (see Wikipedia) is the color of light radiated by an ideal black body heated to high temperature. Some definition seems required before we start. This image is repeated here from the last example at bottom of next page. The sliders are discussed on the next page, but the Temperature slider had a large effect, the Tint slider much less here.

The 'equal' aspect is root of the 'balance' we seek. As the WB is adjusted up towards 5300, the red and green and blue components converge to equal, and white, and perfect white balance (perfect because the card is known to be right, and the equal RGB result is white). The large data spike toward the right end of this histogram is a white card in the photo photographed with flash (the 5300K result). White is a bright gray tone where neutral is defined as equal RGB components, no color cast (specifically, white is defined as bright and equal RGB components). Because we have the known white card in the photo, we can see that in the histogram. We can't see the photo here, but an image 'too blue' is made less blue and more red, to become white. Red and blue channels are shifted oppositely, here to align (balance) the RGB component peaks of a white card (which we know should be white) to remove a blue color cast. ThisВ animated histogram at right shows the concept of what White Balance actually does (the image is from page bottom of page 2). It is a difficult problem, but we have ways to make it easy. White Balance is just a fact of life in Photography. :) But once we start learning, and start seeing good color, correct color will become extremely important to us. IMO, they have not realized yet that it's not. Some users think their camera always gets color right. It's not difficult, but it is something we must tend to. This article is about how you can fix it and salvage a perfect picture. So this subject of White Balance Correction is about when you set the camera right, and still get poor colors (color at least a little wrong is very common, it's not an exact system). Auto WB does try to fix this, halfway well, but it has no clue about the right color either (Auto WB is just making some guesses, which may not be correct). There's a big difference, which photographers have to deal with.

But cameras have no brain, and they do see and capture the color of real life, which we then can see incandescent is orange, which becomes a problem in our photos. This (and more) is named the Land Effect, explained by Edwin H Land (of Polaroid fame). So when we come indoors, from out of cloudy 6000В°K sunlight into incandescent 3000В°K light, we don't realize that incandescent is orange. Humans recognize the color that subject things should be, and we often see what we expect to see. Or rather, our brain amazingly knows to adjust our own white balance, and it can ignore these differences (in common situations).

White balancing exposure x