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Security Camera Viewing Angles
The focal length combined with the sensor size will give you're the viewing angle. A small focal length will
give a wide-angle view and a large focal length will give a narrow telephoto view. Wide-angle lenses have a
better depth of field than telephoto lenses. This means you can focus close up to the cameras as well as at
a distance. Telephoto lenses require a more precise focus adjustment. The calculation for focal length is:
f=h x D/H
Where h = Image Sensor value
1/4" Sensor: h=3.6mm
1/3" Sensor: h=4.8mm
1/2" Sensor: h=6.4mm
Where f = Focal Length
Where D = Distance
Also, if you wish to find the width of objects that you can see after a certain distance you can use this formula:
H=D x h/f
Example: What can I see at 10ft distance if I have a camera with 1/4" sensor and 4mm lens (fixed focal length)?
H=D x h/f
H=10 x 3.6/4
H=9ft
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