Glossary of Digital Photography Terms - From PHOTOS to ART with Photoshop - page 300

changeable Lenses) camera. This is somewhat misleading, since most of these cameras
have no Viewfinder at all - only an LCD Screen.
Negative A photographic master print from which Positive (Normal) Prints are made.
The tonal values are the exact opposite of the Positive or Print. In other words, white ap-
pears as black on the negative and black appears as white. Negatives can be glass plates,
photographic film, or digital files.
Neutral Density Filters A type of filter that screws onto the front of camera lenses.
These filters are gray glass that has no effect on color but reduces the amount of light en-
tering the lens. They are rated in stops so that they can easily be used to change exposure.
They are often used in bright sunlight to allow for longer Shutter Speeds or larger Aperture
Settings.
Neutral Gray Card An 18% gray card that is sometimes used to set White Balance. It
is difficult to define pure black or white, but easy to establish a shade of gray.
Partial Metering AE Exposure based on 9% of the frame and located in the center of
the frame.
Pentaprism A special type of lens that is unique to SLR Cameras, and whose only pur-
pose is to flip the image coming through the lens so that it can be observed right-side-up
through the Viewfinder.
Photosite A specific location on a photographic sensor where photons of a particular
color of light are collected, counted, and recorded.
Pixel A PIcture ELement or point of measureable color intensity and tone that is one
element of a Mosaic-like image composed of many such elements - often in the millions.
Prime Lens A Lens that has a fixed Focal Length. It has no Zoom capability.
RAW A file format for photographic images that saves ALL the image data that the cam-
era is capable of recording.
Rear Standard A moveable frame in Large-Format Cameras that holds the photograph-
ic media - glass plate, film or digital Sensor.