Difference between revisions of "Focal length"
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| − | The focal length of a lens element is the distance from the lens to where a set of parallel rays entering the lens [[focal plane|focuses to a point]]. This distance is measured in millimetres. Longer focal length gives higher magnification. A zoom lens often change in size when zooming to reach the desired focal length. | + | The focal length of a lens element is the distance from the lens to where a set of parallel rays entering the lens [[focal plane|focuses to a point]]. This distance is measured in millimetres. Longer focal length gives higher magnification. A zoom lens often change in size when zooming; to reach the desired focal length. |
[[image:Focallength.png|left|512px]] | [[image:Focallength.png|left|512px]] | ||
[[Category:Photography]] | [[Category:Photography]] | ||
Revision as of 15:33, 29 April 2007
The focal length of a lens element is the distance from the lens to where a set of parallel rays entering the lens focuses to a point. This distance is measured in millimetres. Longer focal length gives higher magnification. A zoom lens often change in size when zooming; to reach the desired focal length.
