Microscan HAWK MV-4000, Manual

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Appendix A
Selecting a Lens
A-2 HAWK MV-4000 Smart Camera Guide
Lens Selection
This section includes information on lens selection, an important consideration when
building your application. The HAWK MV-4000 comes accessorized with a variety of lens
types and sizes to aid you in solving your application challenges.
Choosing the Correct Lens Size for the Application
The primary consideration during lens selection is that the focal length of the selected
lens meets your application’s requirements. The choice of focal length, when combined
with the sensor size , determines the field of view the camera will see at a given distance
between the front of the camera lens and the object, which is called the object distance .
A simple formula can be used to compute any of the four parameters. The formula is:
Sensor Size / Focal Length = Field of View / Object Distance
Example: The application requirement is for a 75 mm wide field of view at an object
distance of 200 mm , using the 1.3 MP sensor. What is the required focal length of the
lens? Rearrange the equation as follows:
Focal Length = Sensor Size / Field of View x Object Distance
Focal Length = 6.144 mm / 75 mm x 200 mm = 16.38 mm
The closest lens to this in the price list is 16 mm .
The sensor sizes needed for the calculation above depend on the model of your HAWK
MV-4000 Smart Camera. The sensor sizes are listed below.
Model Horizontal Sensor Size Vertical Sensor Size
HAWK MV-4000-03, MV-4000-03C 3.072 mm 2.304 mm
HAWK MV-4000-13, MV-4000-13C 6.144 mm 4.915 mm
HAWK MV-4000-20, MV-4000-20C 9.216 mm 5.760 mm
HAWK MV-4000-50, MV-4000-50C 12.442 mm 9.830 mm