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Old July 1st 04, 02:24 AM
Bob
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Default what does the focal distance actually mean?

On Wed, 30 Jun 2004 22:36:49 +0100, "scott" wrote:

When you see a 200mm lens, what is the 200mm actually a measure of?


Focal length.

You know when you take the lens off of your camera and use it burn ants on the
sidewalk by using light from the sun?

The focal length is the distance from the center of the lens to the ant...



I assume it's something to do with how much "zoom" there is, but surely
measuring the angle that is shown by the image would be better?
Eg a
wide-angle lens would be a 90 degree field of view but a telephoto one would
be maybe 5 or 10 degrees.

Is it possible to work out the field of view in degrees from the focal
length?

TIA

Scott