Depth of Field: Means of
describing the area of a photograph that is in focus. A photograph that shows the area
close to the camera and things far away all in good focus is said to have a large depth of
field. A narrow depth of field is when only a thin section of the scene, say from ten to
twelve feet away from the lens, is in focus. With a film camera, setting a large aperture
(wide open iris) gives narrow depth of field, and a small aperture (closed down iris)
gives a wide depth of field. Few cameras in the price range below $1500 can control depth
of field from user input. A change in aperture means that the camera should also change
the shutter speed to maintain correct exposure.
Digital Zoom: Uses digital technology to enlarge an image. Digital zoom does not
have moving parts. It is the electronic enlarging of the middle of an image. The pixels at
the center portion of the CCD are digitally doubled to make the image appear larger
on the display.
Existing data is interpolated to create new data. Resolution is reduced as the center
pixels are enlarged to fill the display. Image files are HALF size (smaller) and require
less space.
In some digital cameras the manufacturer makes the choice to not include an optical zoom
lens. This makes the camera quite a bit smaller as can be seen with some of the
pocket-sized digitals on the market. Some of those pocket cameras offer digital zoom. The
camera takes a portion of the image and magnifies it digitally. Unfortunately, these
images get fuzzy in a hurry because a smaller amount of information is being used to
create a larger image because the camera has to create the missing information.
|
Sony_Digital_Cameras
Kodak_Digital_Cameras
Canon_Digital_Cameras
Olympus_Digital_Cameras
Fuji_Digital_Cameras
Nikon_Digital_Cameras
About
Contact Us
Links
|
