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Photographic film records light that is reflected off an object. If object is grey, how do we get image on film to be grey, if we don’t know what color light is that is hitting grey object and reflecting onto film? Film manufacturers have basically solved this problem by calibrating film to a certain color balance or color temperature. You have two choices, daylight (5500 degrees kelvin) or tungsten (3200 degrees kelvin). So if you are shooting film outdoors, you would choose daylight balanced film. If you are shooting indoors, you would choose tungsten balanced film. Any deviation in color temperature from these two standards would have to be corrected with a color correction filter.
A digital camera works pretty much same as film. The recording device in camera has to be calibrated to color of light in order to get a neutral image. Neutral meaning no color cast. A white will record as white. Different digital cameras use different methods of letting you choose color balance. Most digital cameras will have an auto white balance function. In most situations this works fairly well. However there are occasions when camera can be fooled. This is why a lot of digital cameras also give you a way of setting white balance manually. Either through a list of choices like daylight, shade or overcast, or a list of color temperatures such as 3200, 5500 and 6500. Some digital camera’s take it a step further and let you choose a custom white balance by having you photograph something white and use it as a reference for white balance.
By using white balance in your digital camera you can “set it wrong” to create different moods of light in your images.As an example, lets say you are photographing a field covered in snow on a sunny day but you want image to reflect fact that it is only 10 degrees outside. If you were to set your digital camera’s white balance at anything lower then 5500 degrees kelvin resulting image would have a blue cast to it making your image ‘feel’ cold. Experiment a little with it. Don’t just play around with aperture and shutter speed, play with white balance too.
Ken is a long time photography enthusiast who has created a web based publication on photography techniques. See more tips and techniques at www.explore-photography.com