Revised August 2006
Consider point-and-shoot cameras and single-lens-reflex (SLR)
cameras as specialized tools -- select the right tool to do the job
right. Point-and-shoot cameras automatically select the aperture
and shutter speed. SLR cameras give the photographer creative control
in creating the final image.
The simplest camera on the current market is the lens-shutter
camera, also known as a point-and-shoot camera. These cameras are
easy to use, give good results, and are extremely affordable.
Point-and-shoot cameras are very automatic: auto flash, auto
exposure, auto wind, auto rewind, and auto shutoff. Taking pictures
is a snap! Look through the viewfinder, press the button, and the
camera captures the picture. The camera selects the shutter speed
and aperture for you.
Point-and-shoot cameras have long been the favorite for family
and vacation pictures. The flash has a limited range, usually 10
to 15 feet, which is ideal for birthday parties and holiday celebrations.
In the corporate world, point-and-shoot cameras are ideal for ID
cards, employee newsletters, real estate brochures, and for loading
simple images on the Internet.
Single-lens-reflex (SLR) cameras
Single-lens-reflex (SLR) cameras provide capabilities not found
in point-and-shoot cameras; for example, interchangeable lenses
and other accessories which give the photographer greater control
and flexibility. SLR cameras allow photographers to visually check
image sharpness. The effects of changing lenses or adding attachments
are immediately visible in the viewfinder.
SLR cameras use the same lens to view and take a picture. Just
before the SLR shutter opens, a mirror which reflects the image
into the viewfinder flips up, and allows the image to fall on the
film (or the digital camera charge-coupled device) as the shutter
opens. This provides more accurate framing, especially when photographing
SLR cameras offer several advantages over their point-and-shoot
Most modern SLR cameras have "through-the-lens" (TTL)
metering to provide greater accuracy. The exposure is determined
from the amount of light actually passing through the lens which "takes" the
Parallax error is eliminated because the photographer sees
exactly what the lens will place on the film. This is especially
important when taking close-up photographs.
The camera can be attached to a telescope or a microscope,
or fit with diffusers or masks, to allow the photographer to see
the precise image the lens will produce on film.
The camera is very versatile. Lenses can be removed and
other lenses and accessories can be fitted to the camera body. Interchangeable
lenses provide views unattainable with standard or "normal" lenses:
Wide-angle lenses include more subject
matter in a frame.
Telephoto lenses appear to bring subjects closer.
Macro lenses allow for extreme close-ups.
Zoom lenses, a favorite of sports photographers and photojournalists,
offer precise framing and reduce the need to crop the final image.
The SLR camera offers a wide choice of shutter speeds.
Use a fast shutter speed to freeze action. Use a slow shutter speed
to capture an image in very low light or for artistic effect; for
example, to exaggerate running water or to interpret motion poetically.
The adjustable aperture of an SLR camera can affect depth
of field which represents how much of the foreground and background
are in focus. For example, the photographer might choose a shallow
depth of field for a head shot so the subject is sharp but the background,
which would distract the viewer, is blurred and almost abstract.
When shooting an image of hiking boots against the backdrop of a
river, photographers can choose a smaller aperture to capture the entire
scene in focus or choose a large aperture to focus only on the boots.
SLR cameras give photographers more control because the camera
can be adjusted to a variety of lighting and focusing situations.
For example, a backlit subject would confuse most automatic exposure
systems but a photographer would recognize the situation and compensate
by using a greater exposure. A window between the subject and the
camera would fool most infrared automatic focusing systems (the
window glass would reflect the infrared focus beam, and cause the camera
to focus on the glass). A photographer would use manual focus to
obtain a quality image.
SLR camera applications
SLR cameras can be equipped with powerful
flash units to light subjects from 60 or 70 feet away, which makes
them perfect for events or wedding receptions.
SLR cameras can be connected to or synchronized with studio-lighting
equipment for sophisticated portraiture exposures.
Image quality on the Internet now rivals that of high-end
print media. Superior image quality requires sophisticated lighting.
Photographers can attach SLR cameras to studio lighting equipment
and use soft lights or hot lights to create appealing portrait and
SLR cameras are an excellent choice for creating sales
flyers, online catalogs, and technical or training manuals.
Crime scene photographers often prefer the SLR camera's
precise focusing and ability to capture images in low-light situations.
The photographer can use different lenses and select the best shutter
speed and aperture to create the optimum final result.
Technical Information Bulletins provide information of limited or specific application. Responsibility for judging the applicability
of the information for a specific use rests with the end user.