Table of Contents
Advertisement
Glossary
Appendix >
Exposure
The amount of light allowed to reach the camera's sensor. Exposure is
controlled by a combination of the shutter speed, the aperture value,
and ISO sensitivity.
Flash
A speed light that helps to create adequate exposure in low-light
conditions.
Focal length
The distance from the middle of the lens to its focal point(in millimeters).
Longer focal lengths result in narrower angles of view and the subject is
magnified. Shorter focal lengths result in wider angles of view.
Histogram
A graphical representation of the brightness of an image. The horizontal
axis represents the brightness and the vertical axis represents the
number of pixels. High points at the left (too dark) and right (too bright)
on the histogram indicate a photo that is improperly exposed.
H.264/MPEG-4
A high-compression video format established by international standard
organizations ISO-IEC and ITU-T. This codec is capable of providing
good video quality at low bit rates developed by the Joint Video Team
(JVT).
Image sensor
The physical part of a digital camera that contains a photosite for each
pixel in the image. Each photosite records the brightness of the light
that strikes it during an exposure. Common sensor types are CCD
(Charge-coupled Device) and CMOS (Complementary Metal Oxide
Semiconductor).
ISO sensitivity
The sensitivity of the camera to light, based on the equivalent film speed
used in a film camera. At higher ISO sensitivity settings, the camera
uses a higher shutter speed, which can reduce blur caused by camera
shake and low light. However, images with high sensitivity are more
susceptible to noise.
141
Advertisement
Table of Contents
