Better Available Light Digital Photography : How to Make the Most of Your Night and Low-light Shots

Basic exposure 41

easy to spot. Again, just because you’ve got blinkies doesn’t

mean the image is unacceptable. The bottom line rests with you,

the photographer, to be in fi nal control of the exposure.

If you’re working in Manual exposure mode and the photo-

graphs seem too light or dark (based on the histogram), you must

adjust either the shutter speed or the aperture to compensate. If

the image is too dark, you’ll either open the aperture to a faster

one (smaller number), allowing more light onto the sensor, or

you’ll use a slower shutter speed that also allows more light to

strike the sensor. Because most of us are using one of the other

exposure modes (Shutter Priority, Aperture Priority, or Program),

we’ll sometimes use the Exposure Compensation controls to

tweak the amount of light hitting the sensor, although Joe seems

to use it more. Cameras allow over- and underexposure control

in increments of 1/3 f-stops. Compare that to the f/16 and shutter

speed to ISO method, or the guidelines packaged with fi lm

(talked about earlier in the chapter). We now have precise control

over our exposure. Barry and many of his colleagues routinely

set their Canon EOS digital SLRs to a +1/3 or −2/3 setting for

much of their interior work. When Barry used Nikon cameras, he

often had the camera set to −1/3 exposure setting for outdoor

photography. To fi nd the best basic settings for your type of work,

you should take the time to perform exposure tests with your

specifi c camera. The beauty of digital photography is the ability

to take an unlimited number of images and study and learn from

them, without the expense of fi lm, processing, and prints. There

are no excuses for not mastering the functions of your camera.

The left side of the graph displays
information about shadows,
whereas the right side deals with
the highlights. Keep the data
within the left-to-right boundaries
of the histogram, although spikes
shooting above the top aren’t good
either. A perfectly exposed image
forms a good bell curve on the
histogram. It doesn’t spike any-
where along the top, nor does it go
off the graph on either side.
Underexposure can look like this
histogram, but keep in mind that
not all over- or underexposed
images are bad. You may want an
image with darkness and mood or
one with high key lighting.