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CHAPTER
NIGHT AND LOW-LIGHT PHOTOGRAPHY / All About Light and Exposure

Different light sources

There are a lot of different light sources out there,
and while you may think that shooting at night
or in low light would reduce the number of
sources, it actually increases them. Photograph
outside during the day when the predominant
light source is the sun, and take the same location
at night. The chances are that there will be a
variety of different light sources all competing
with each other and combining to illuminate the
scene. This can include sodium vapor streetlights,
newer fluorescent bulbs in signs and buildings,
the variety of illuminated building signs, car
headlights and taillights, neon, and even the
moon. Each of the different light sources has a
different color.

Color temperature and the Kelvin scale

The Kelvin scale is used to describe the color of a
specific light. It gives a constant measurement
that can be used to adjust the color of an image
either in the camera or in postproduction. The
Kelvin scale was created by the British physicist
William Thomson in the late 1800s. He heated
up a block of carbon and noticed that the block
changed colors as it changed temperature. The
color started out as a dark red and slowly changed
to a blue-white light as it got hotter. This became

the basis for the Kelvin scale: deep oranges and

reds are the lower temperatures and bright blue

and white are the higher temperatures. Because of

the Kelvin scale’s standard numerical description,

it is possible to tell the camera what the color of

the light in the scene is using the white balance

setting on the camera.

White balance

Setting the white balance on your camera is the

way to get the most accurate color when photo-

graphing under any light source. Check your

camera manual for the location of the white bal-

ance menu or button. Make sure you choose the

correct one before taking the photo so you get the

most accurate color.

The following list introduces the standard white

balance settings:

    ■   Auto white balance. Most cameras have an

auto white balance setting that allows the

camera to set the white balance for every

shot. This means that the camera looks at the

light present just as the shutter release button

is being pressed and tries to get the most accu-

rate results and the truest colors. The down-

side is that the white balance is different,

even if only slightly, for every photograph as

the camera makes slight adjustments, depend-

ing on the light. If you are taking a series of

photos in the same place at the same time,

this can cause each of the images to look a lit-

tle different. I have found that the auto white

balance setting works great in most situations,

but not all, and when shooting under multiple

light sources either indoors or at night, the

auto white balance is probably not the best

choice.

The Kelvin scale is used to describe the color of
the light and the white balance setting on the
camera.

One of the best reasons to shoot

using the RAW file type is so that you

can easily fix the white balance in postproduction.

tip