Difference between revisions of "Angle of view"
From ScienceZero
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| + | The angle of view is a function of the focal length of the lens and the dimension of the sensor. | ||
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d is the dimension of the sensor in the same rotation as you want to know the angle of view (horizontally, vertically or diagonally but any rotation is possible). f is the effective [[focal length]] of the lens. | d is the dimension of the sensor in the same rotation as you want to know the angle of view (horizontally, vertically or diagonally but any rotation is possible). f is the effective [[focal length]] of the lens. | ||
::<math>\alpha = 2 \arctan \frac {d} {2 f}</math> | ::<math>\alpha = 2 \arctan \frac {d} {2 f}</math> | ||
| Line 5: | Line 7: | ||
| − | As an example we calculate the field of view | + | As an example we calculate the field of view of a 30 mm lens on a Canon D20 that has a horizontal sensor dimension of 22.5 mm. |
::<math>\alpha = 2 \arctan \frac {22.5} {2 \times 30}</math> | ::<math>\alpha = 2 \arctan \frac {22.5} {2 \times 30}</math> | ||
That gives us a horizontal angle of view of 41.1° | That gives us a horizontal angle of view of 41.1° | ||
[[Category:Photography]] | [[Category:Photography]] | ||
Revision as of 04:03, 16 February 2007
The angle of view is a function of the focal length of the lens and the dimension of the sensor.
d is the dimension of the sensor in the same rotation as you want to know the angle of view (horizontally, vertically or diagonally but any rotation is possible). f is the effective focal length of the lens.
- <math>\alpha = 2 \arctan \frac {d} {2 f}</math>
(Arctan (Inverse Tangent) can be found as atan or tan-1 on some calculators)
As an example we calculate the field of view of a 30 mm lens on a Canon D20 that has a horizontal sensor dimension of 22.5 mm.
- <math>\alpha = 2 \arctan \frac {22.5} {2 \times 30}</math>
That gives us a horizontal angle of view of 41.1°
