ChApter 1. digitAl CAmerAs & imAges
24 For more on textbooks in digitAl photogrAphy, visit http://www.photoCourse.Com
In this cutaway view
of a Canon SLR you
can see the mirror
that bounces light up
into a prism for the
viewfinder. The mirror
swings up out of the
way when you take a
picture. Courtesy of
Canon.
by various focal length lenses. You can almost always see more than the lens
will capture so you can make fine adjustments in composition and better
anticipate movement into the frame.- Electronic viewfinders use a small LCD monitor built into the viewfinder
to display the same through-the-lens image seen by the image sensor. Many
of these cameras let you switch between the monitor and viewfinder and both
show exactly the same scene and same information. Because these viewfind-
ers are electronic you can display menus and change settings without lower-
ing the camera from your eye. This is especially useful on bright days when
a monitor is hard to read because of glare. These viewfinders are also great
if you normally need reading glasses because you can use the diopter adjust-
ment control to bring menus and images into focus without first putting on
your glasses. The biggest shortcomings of these viewfinders are their refresh
rate and resolution. A slow refresh rate means that as you move the camera,
the image on the screen lags behind the scene you are pointing at. When pan-
ning, the screen seems to jump between frames. On some cameras the refresh
stops when you press the shutter button halfway down to lock focus so the
image you capture may be different from the one you see. The low resolution
of these viewfinders makes it hard to tell exactly what you are photographing.
You don’t see fine details, colors, or tones the way they actually are.
When considering a viewfinder, here are a few other things to think about: - With the exception of rangefinders where the viewfinder shows more than
the area that will be captured, most viewfinders only show about 95%. - Eyepiece covers are needed on SLRs to keep light from leaking through the
viewfinder when using a self-timer or remote control and you are not block-
ing the light by looking through the viewfinder. - Optical viewfinders on point and shoot cameras don’t display important
shooting information such as focus and exposure settings. - Fixed lens cameras with electronic viewfinders differ from SLRs in that they
don’t use a movable mirror to bounce light into the viewfinder. - You can connect some cameras to a TV while you are taking pictures and let
others see them as they are taken. This sets up lively interaction if there is a
group of people watching as you take pictures.
Slipping an eyepiece
cover over a viewfinder
blocks light from
entering and affecting
the exposure when
using a self-timer or
remote control.
Some point and
shoot cameras
have eliminated the
viewfinder so you have
to compose images
using the monitor.
Electronic viewfinders
are small flat-panel
displays inside the
viewfinder. Courtesy of
Zight.
The Leica M8 viewfinder
has lines that indicate
the coverage of a 24mm
and 35mm lens.