GLOSSARY^213
viewfinder, optical A separate window that shows what would be included in a photograph,
but only approximately.
viewfinder, single-lens reflex A viewfinder whose image comes directly through the same
lens that will be used for taking the picture.
viewfinder, TTL (through-the-lens) A viewfinder that looks through the lens to use the same
image produced by the lens to create a photograph.
W–X–Y–Z
white balance An automatic or manual control that adjusts the brightest part of the scene so it
looks white.
white point The color that is made from values of 255, each for red, blue, or green in a cam-
era’s sensor image, a monitor, or a scanner. On paper, the white point is whatever color the paper
is.
wide-angle lens A lens with an angle of view between 62° and 84°.
xD Picture Card Weighing 2.8 grams and not much bigger than a penny (20mm ×25mm×
1.78mm), the xD Picture Card is used in Olympus and Fuji digital cameras. There are two types of
xD cards, M and H. Type H is the newer and faster of the two.
zone system A method developed by photographer Ansel Adams for setting exposure compen-
sation by dividing the entire grayscale range in 11 zones from 100% white to 100% black.
zoom, digital A way of emulating the telephoto capabilities of a zoom lens by enlarging the cen-
ter of the image and inserting new pixels into the image using interpolation. See also interpola-
tion.
zoom, optical A method that changes the focal length of a lens to change its angle of view from
wide angle to telephoto. Optical zoom is preferable to digital zoom.
zoom lens A lens that lets you change focal lengths on-the-fly.