Controlling Exposure

Swallowtail Butterfly on Lilac Bush
Garnet, Montana


Using Manual exposure mode can produce more consistent results than other exposure modes, especially when photographing a moving subject like this swallowtail butterfly. It was one of several different butterflies enjoying the sun and the nectar from the lilac blossoms. 

But as they flew from flower to flower the background brightness changed. This would cause a setting like Program or Shutter Priority, in which the camera automatically adjusts the exposure, to give varying results.

By setting the camera to Manual exposure mode and dialing in the ISO, shutter speed and aperture appropriate for the butterfly, I could follow it around the bush and still keep its exposure constant. A combination of ISO 200, 1/250 second shutter speed and f/8 aperture, let me take a series of pictures and have the exposures all be the same.

Learn to take creative control of your camera's settings in Mastering Manual Exposure, an online class beginning November 5, 2020, through the Lifelong Learning Center in Missoula, Montana. Click here to register.