The following parameters are the most basic concepts of imaging and are important to understand when studying more advanced topics:
- Field of View (FOV): The viewable area of the object under inspection. This is the portion of the object that fills the camera’s sensor.
- Working Distance (WD): The distance from the front of the lens to the object under inspection.
- Resolution: The minimum feature size of the object that can be distinguished by the imaging system. Learn more in Resolution.
- Depth of Field (DOF): The maximum object depth that can be maintained entirely in acceptable focus. DOF is also the amount of object movement (in and out of best focus) allowable while maintaining focus. Learn more in Depth of Field and Depth of Focus.
- Sensor Size: The size of a camera sensor’s active area, typically specified in the horizontal dimension. This parameter is important in determining the proper lens magnification required to obtain a desired field of view.
- PMAG: The Primary Magnification of the lens is defined as the ratio between the sensor size and the FOV. Although sensor size and field of view are fundamental parameters, it is important to realize that PMAG is not.
PMAG = Sensor size(mm)/field of view(mm) (1)
Note: Typically, only horizontal values are used.
Fig1: Diagram of Fixed Focal Lenses