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Lens Calculator

How to find the focal length

hobject vertical dimension
lobject horizontal dimension
Dobject distance from lens

How to find the focal length
Sensor format1"2/3"1/2"1/3"1/4"
Knowing the height of the viewed objectf= 9.6 D/hf= 6.6 D/hf= 4.8 D/hf= 3.6 D/hf= 2.4 D/h
Knowing the width of the viewed objectf= 12.7 D/lf= 8.8 D/lf= 6.4 D/lf= 4.8 D/lf= 3.4 D/h
How to find the object dimensions
Sensor format1"2/3"1/2"1/3"1/4"
To calculate the height of  the viewed object.h= 9.6 D/fh= 6.6 D/fh= 4.8 D/fh= 3.6 D/fh= 2.4 D/f
To calculate the width of  the viewed object.l= 12.7 D/fl= 8.8 D/fl= 6.4 D/fl= 4.8 D/fl= 3.4 D/f


Police Guidelines
Type of view   Height   This is based on...
Identification1.33m1.6m man = 120% screen height
Recognition3.2m1.6m man = 50% screen height
Detection16m1.6m man = 10% screen height
Monitoring32m1.6m man = 5% screen height