|MadSci Network: Physics|
A long focal-length lens will magnify more. Sometimes they are called "narrow field of view" lenses because they cover a much smaller angle of view than a "wide field of view" lens. A fish-eye lens has an extremely wide field of view (~180 deg). A telephoto lens and a telescope are examples of narrow field of view lenses. Both have very long focal-lengths. A typical 35mm camera uses a lense of between 30 and 50mm focal length for "standard" view (most like the human eye). Wide angle lenses are usually less than 30mm and telephoto are usually greater than 50mm. Todd Jamison Chief Scientist, Observera, Inc.
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