Glossary
Appendixes
164
Optical zoom
This is a general zoom which can enlarge images with a lens and does not degrade
the 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.
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.
