38 Nebraskaland • June 2021
most of us, 1/60th of a second is about the slowest shutter speed we can
safely use when hand-holding a camera. With telephoto lenses, you want
to use a faster shutter speed number than the telephoto number (e.g. use at
least 1/300th of a second for a 300mm lens). Vibration reduction technology
in newer lenses can buy you a little leeway there, but it's still safest to follow
the shutter speed-lens length rule. These issues are why photographers
rely on tripods, which hold the camera steady when you need to use a slow
shutter speed in order to get the depth of fi eld you want in an image.
Deciding what combination of shutter speed and aperture to use for a
photo can be tricky, and you can't necessarily trust your camera to choose
the best answer. Your camera won't know that you want both the fl ower
in the foreground and the hills in the background of an image to be sharp.
Alternately, your camera can't anticipate that you want to blur out the
distracting background in a close-up photo of a bee on a fl ower. When you're
trying to make sure the eye of a bobolink is in sharp focus, your camera
won't know that you don't give a fl ip about depth of fi eld and just need all
the shutter speed you can get.
Setting the Camera on a Priority
One solution is to set your camera on either aperture priority or shutter
speed priority, in which you tell the camera which is more important to
you and let the camera work within that set of parameters. If you set the
camera on aperture priority, you can tell the camera to keep the aperture
set at a generous f/16, which will make sure you have adequate depth of
fi eld to make both the foreground fl owers and the background hills sharp.
Low light forced me to use a slow shutter speed for this photo, especially
because I wanted a small aperture to maximize depth of fi eld. I used a
tripod and a shutter speed of about ½ second. Note the eff ect of the slow
shutter speed on the small waterfalls behind the fungus.
ABOVE: A fast shutter speed of 1/640
second counteracted the breeze that
was moving these fl owers back and
forth.
