Appendixes
151
Glossary
Vignetting
A reduction of an image’s brightness or saturation at the periphery
(outer edges) compared to the center of the image. Vignetting
can draw interest to subjects positioned in the center of an
image.
White balance (color balance)
An adjustment of the intensities of colors (typically the primary
colors red, green, and blue), in an image. The goal of adjusting
the white balance, or color balance, is to correctly render the
colors in an image.
Optical zoom
This is a general zoom which can enlarge images with a lens and
does not deteriorate quality of images.
Quality
An expression of the rate of compression used in a digital image.
Higher quality images have a lower rate of compression, which
usually results in a larger file size.
Resolution
The number of pixels present in a digital image. High resolution
images contain more pixels and typically show more detail than
low resolution images.
Shutter speed
Shutter speed refers to the amount of time it takes to open and
close the shutter, and it is an important factor in the brightness of
a photo, as it controls the amount of light which passes through
the aperture before it reaches the image sensor. A fast shutter
speed allows less time to let light in and the photo becomes
darker and more easily freezes subjects in motion.