White Balance is a concept that is a little hard to explain. Not because Its a very complicated subject because its not. Its a very simple topic which a little hard to be described in words.
Ever noticed how colors in a picture look a little different depending upon the atmosphere the shot was taken in? For example, shot taken under bright sun will have a slight orange / yellowish feel to it whereas If you took an evening shot of a beach, the overall shot will have a slight bluish touch with it. For a better understanding, try taking a few shots, preferably of the same place or subject, under different light settings. You will notice how overall effect on the image changes. Daylight effect will warm your picture up a bit whereas the shade will add a slight cool bluish effect to it.
Human eyes are very good and precise at judging what is white, no matter what the lighting effect is. You will know that a color is white even if there was a red light falling upon it. Digital cameras however have a great difficulty rendering it because the light that is reflecting off the subject may be creating a green blue or orange cast. You may have taken a shot that looked different to your eye but when you looked at the final image, colors were looking different. We change the white balance setting in order to get the colors in an image as accurately as possible or rather as pleasing as it can look to us. White balance is the process of removing unrealistic color casts, so that objects which appear white in person are rendered white in your photo. Let us say that you clicked a picture of a white subject in candle light. Do you think that the subject will have the same white color in image as you saw it in real? It will not because the candle light reflecting off the subject will turn it slightly orange or yellow in the photo. In order to correct this, you may tell the camera to cool down a bit so the warm orange effect gets reduced significantly.
White Balance Presets:
Modern day DSLRs come equipped with presets that can help you change the white balance just by moving the dial a bit or at press of a button. Lets take a look at what some of these presets are and what effect they create.
1. Auto – As the name suggests, you leave it for the camera to decide the white balance for each shot.
2. Tungsten – This setting generally cools down the colors in photos and is mostly used for indoor shoots, such as bulb lighting and hence it is symbolized with a bulb.
3. Fluorescent – This compensates for the ‘cool’ light of fluorescent light and will warm up your shots.
4. Daylight/Sunny – It kind of averages out the overall effect, to more of a normal mode.
5. Cloudy – This setting generally warms things up a touch more than ‘daylight’ mode.
6. Flash – The flash of a camera can be quite a cool light so in Flash WB mode you’ll find it warms up your shots a touch.
7. Shade – The light in shade is generally cooler (bluer) than shooting in direct sunlight so this mode will warm things up a little.
Manual White Balance Adjustment
In most of the cases, the above mentioned presets do a fine job but there can be times when you will find your camera still confused and not rendering white as white. In this case, you will have to hold out a white object, like a piece of paper, to tell the camera what color white is and then take the shot. Take a look at the shots below.
The first image was taken in Auto white balance mode. Notice how the camera added an overall warm effect to the image. Second shot however was taken in manual white balance adjustment mode. A white piece of camera was held in front of the camera to tell it what color white is. Notice how the color cast in the second image appears.
