User Manual

104
Chapter 12: Taking Great Pictures
Microsoft Digital Image Standard User’s Manual
ISO Setting or Equivalent
When taking pictures on film, you have the opportunity to select different types
of film for specific uses. Films are available in different speeds that are more
sensitive or less sensitive to light.
The film speed is measured by ISO number. A high-speed film, such as ISO
800, is ideal for low-light situations or action photography, since the film
requires less light to properly expose the photo. Slow-speed films, such as
ISO 100 or ISO 200, are good for photographing in bright daylight, since they
require a lot of light. If you plan on using the same roll of film for multiple
settings and light levels, ISO 400 film is a good compromise and does relatively
well in most situations.
Faster films generally produce grainier pictures than lower-speed films. Some
of the newer varieties of professional grade high-speed films produce a finer
grain structure, which is less noticeable.
Since digital cameras use an image sensor instead of film, there is no way to
actually change the film speed. However, many digital cameras provide the
digital equivalent of an ISO. Sometimes called the sensitivity setting, this
feature, in effect, allows you to change the ISO setting. For example, if you are
in a low-light situation, you can switch from ISO 100 to ISO 400.
With most digital cameras, setting the digital equivalent of the ISO setting to a
faster speed can introduce noise into the picture. Similar to the graininess from
high-ISO film, noise is pixels of random color that mar the picture. Cameras
vary widely, so you should experiment with your digital camera’s ISO settings
and examine the results.
In low-light situations, consider turning off the flash and setting the camera to a
faster ISO setting. This might produce some noise in the picture. But that result
might be preferable to what you’d get by taking the photo at slower ISO setting
with the harsh lighting of the on-camera flash.
ASA versus ISO
If you have an older
camera, the film speed
dial might be labeled
ASA instead of ISO.
These film speed
ratings are the same,
and the ratings are
interchangeable.
Avoid sharpening
pictures that have
noise
Do not use the sharpen
feature in Digital Image
on digital photos with
noticeable noise;
sharpening accentuates
the inaccurate pixels.