Matrox Iris GT MIL, Installation And Technical Reference, Page: 105 / 256

Calculating the required focal length 105
Calculating the required focal length
To calculate the required focal length, measure the distance from the smart camera
to the object, as well as the height (vertical size) and width (horizontal size) of the
object.
Use the following calculations to determine the required focal length for your
situation.
By selecting the smallest focal length from the vertical and the horizontal focal
length calculations, you assure that both the vertical and horizontal dimensions
of your object fit within the view of your lens.
The sensor chip type of your smart camera determines the horizontal and vertical
constants required in the above-mentioned calculations. Each type of Matrox
Iris GT smart camera uses a different sensor chip type.
and
Product name Sensor chip type Horizontal constant Vertical constant
GT300 1/3” 4.8 mm 3.6 mm
GT1200 1/3" 4.8 mm 3.6 mm
GT1900 1/1.8" 7.1 mm 5.3 mm
Matrox Iris GT
Lens
Distance from object
Height
of
object
Object
Vertical constant Distance from object
×
Vertical size of object Vertical constant +
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Horizontal constant Distance from object
×
Horizontal size of object Horizontal constant +
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