Available Light Photography

By Tom Davenport, Prairie Photography

Prairie Home

 

ISO, Aperture and Shutter Speed are the three determining factors in proper available light image exposure.

 

ISO - The designation for the sensitivity to light of the film or digital sensor. The higher the number, the more sensitive to light the film or digital sensor is, the lower the number the less sensitive to light the film or digital sensor is.

  1600 ISO, VERY sensitive to light. Good for night sports in most gymnasiums or under the lights at most stadiums. A high ISO number will give you more grain or noise.

  800

  400

  200

  100 ISO LESS sensitive to light. Good for bright daylight.

 

Aperture – The amount of light the lens lets into the camera, designated by “f-stop”.  The smaller the aperture size or opening size, the larger the number.

    f-2.8 – Very large opening allows more light to the film or digital sensor. Less depth of field or depth of focus.

   f-4

   f-5.6

   f-8

   f-11

   f-16

   f-22 – Very small opening allows less light to the film or digital sensor. More depth of field or depth of focus.

 

Shutter Speed – Shutter speed refers to how fast the shutter cycles, designated in seconds or fractions of a second. On many cameras, shutter speeds from 30 seconds to

  1/4000 of a second are available. To freeze action, a minimum of 1/500th of a second is desirable. Not always possible, in fact never possible at night in any of the

  nearby football stadiums or gymnasiums.  

1/4000 of a second – Very Fast Shutter allows less light to the film or sensor. A fast shutter speed will freeze action.

1/2000

1/1000

1/500 - Minimum to freeze most action.

1/250 - Can freeze action, especially if it is coming to you.

1/125

1/60th of a second – Slow Shutter Speed. Action will be blurred.

1/30

1/15

1/8

1/4

1/2

1 Second

2

4

8

15

30 Seconds – VERY Slow Shutter Speed. A tripod is necessary. Action will be nothing but a blur.

 

A good general exposure for outside night sports in most of our local stadiums is ISO 1600, Aperture f-2.8, Shutter Speed 1/250th of a second. You will need to be able to set your camera to "MANUAL" or "M" mode to achieve these settings. This exposure is a general rule, applying to the middle of the field.

If the largest aperture you can get is f4 or f5.6, you will have a difficult time getting a clear, sharp picture unless you turn on your flash. And then, all bets are off because flash is a different animal all together and for another discussion!