Is possible to calculate the focal length necessary to see an object placed to a certain distance by knowing the dimensions of the sensor ( 1 ", 2/3 ", 1/2 ", 1/3 ", 1/4 " ).
It is also possible to know the focal of the objective in use, by calculating the dimensions of what is seen.
The table which follows contains the formulas necessary for the calculations.
E' possibile calcolare la lunghezza focale necessaria per vedere un oggetto posto ad una determinata distanza conoscendo le dimensioni del sensore (1", 2/3", 1/2", 1/3", 1/4").
E' anche possibile, conoscendo la focale dell'obiettivo da usare, calcolare le dimensioni di quanto viene visto.
La tabella che segue contiene le formule necessarie per i calcoli.
f | Focal length (mm) |
h | Object Height |
I | Object width |
D | Object distance from the lens |
FOCAL LENGHT CALCULATION
CCD FORMAT |
1" |
2/3" |
1/2" |
1/3" |
1/4" |
Knowing the height (h) of the object to be seen. |
f= 9.6 D/h |
f= 6.6 D/h |
f= 4.8 D/h |
f= 3.6 D/h |
f= 2.4 D/h |
Knowing the width (l) of the object to be seen |
f= 12.7 D/l |
f= 8.8 D/l |
f= 6.4 D/l |
f= 4.8 D/l |
f= 3.4 D/l |
OBJECT DIMENSION BY FOCAL LENGHT
CCD FORMAT |
1" |
2/3" |
1/2" |
1/3" |
1/4" |
To calculate the height (h) of the object. |
h= 9.6 D/f |
h= 6.6 D/f |
h= 4.8 D/f |
h= 3.6 D/f |
h= 2.4 D/f |
To calculate the width (l) of the object |
l= 12.7 D/f |
l= 8.8 D/f |
l= 6.4 D/f |
l= 4.8 D/f |
l= 3.4 D/f |