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For 1/3" CCD
using a standard 3.6mm lens
as supplied with most cameras
|
Object distance from lens |
Object horizontal dimension | Object vertical dimension |
|
metres or feet |
||
| 2 | 2.6 | 2 |
| 4 | 5.3 | 4 |
| 6 | 8 | 6 |
| 8 | 10.6 | 8 |
| 10 | 13.3 | 10 |
| 12 | 16 | 12 |
| 14 | 18.6 | 14 |
| 16 | 21.3 | 16 |
| 18 | 24 | 18 |
| 20 | 26.6 | 20 |
| 22 | 29.3 | 22 |
| 24 | 32 | 24 |
| 26 | 34.6 | 26 |
using a standard 4.3mm lens
as supplied with 27C camera
| Object distance from lens | Object horizontal dimension | Object vertical dimension |
|
metres or feet |
||
| 2 | 2.2 | 1.6 |
| 4 | 4.4 | 3.3 |
| 6 | 6.6 | 5.0 |
| 8 | 8.9 | 6.6 |
| 10 | 11.1 | 8.3 |
| 12 | 13.3 | 10.0 |
| 14 | 15.6 | 11.7 |
| 16 | 17.8 | 13.3 |
| 18 | 20.0 | 15.0 |
| 20 | 22.3 | 16.7 |
| 22 | 24.5 | 18.4 |
| 24 | 26.7 | 20.0 |
| 26 | 29.0 | 21.7 |
1/4" CCD
using a standard 3.6mm lens
as supplied with 2120 camera
| Object distance from lens | Object horizontal dimension | Object vertical dimension |
|
metres or feet |
||
| 2.0 | 1.9 | 1.3 |
| 4.0 | 3.8 | 2.7 |
| 6.0 | 5.7 | 4.0 |
| 8.0 | 7.6 | 5.3 |
| 10.0 | 9.4 | 6.7 |
| 12.0 | 11.3 | 8.0 |
| 14.0 | 13.2 | 9.3 |
| 16.0 | 15.1 | 10.7 |
| 18.0 | 17.0 | 12.0 |
| 20.0 | 18.9 | 13.3 |
| 22.0 | 20.8 | 14.7 |
| 24.0 | 22.7 | 16.0 |
| 26.0 | 24.6 | 17.3 |
How to find the focal length
 |
| f | focal |
|---|---|
| h | object vertical dimension |
| l | object horizontal dimension |
| D | object distance from lens |
How to find the focal length |
|||||
Sensor format |
1" |
2/3" |
1/2" |
1/3" |
1/4" |
Knowing the height of the viewed object |
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 of the viewed object |
f= 12.7 D/l | f= 8.8 D/l | f= 6.4 D/l | f= 4.8 D/l | f= 3.4 D/h |
How to find the object dimensions |
|||||
Sensor format |
1" |
2/3" |
1/2" |
1/3" |
1/4" |
To calculate the height of the viewed 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 of the viewed 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 |
