Focal length
When selecting a lens for a specific machine vision task, first of all, the focal length has to be calculated. This calculation is based on the following three parameters:
- the size of the object that has to be captured,
- the distance between this object and the lenses' leading edge and
- the size of the CMOS sensor or CCD sensor, expressed as format.
The article Lenses for industrial cameras shows how to calculate the focal length based on these three parameters.
Important: There are industrial cameras on the market whose resolution is variable. A typical example are the The Imaging Source One4all cameras. A variation of the resolution leads to a variation of the format and this in turn, affects the calculation of the focal length.
