How to calculate industrial lenses

 In the machine vision system, the main function of the industrial lens is to place the imaging target on the photosensitive surface of the image sensor, and the quality of the lens directly affects the overall performance of the machine vision system. Reasonable selection and installation of the lens is the key to the design of the machine vision system. important link. Here’s how industrial lenses are calculated:

1.WD object distance working distance (Work Distance, WD). 

2.FOV field of view (Field of View, FOV)

3.DOV Depth of Field. 

4.Ho: height of field of view

5.Hi: The height of the effective imaging surface of the camera (Hi represents the size of the sensor image surface) 

6.PMAG: Lens magnification 

7.f: focal length of the lens 

8.LE: Extended distance of lens image plane 

Camera sensor size:

1/4inch(3.2mm×2.4mm)；1/3inch(4.8mm×3.6mm)；

1/2inch(6.4mm×4.8mm)；2/3inch(8.8×6.6mm)；

1inch(12.8mm×9.6mm)

Camera and lens selection tips:

1. Main parameters of the camera:

Sensing area SS (Sensor Size)

2. Main parameters of the lens:

Focal length FL(Focal Length)

Minimum Focal Distance Dmin(minimum Focal Distance)

3.Other parameters:

FOV (Field of View) 

pixel pixel  

FOVmin=SS(Dmin/FL)

Such as: SS=6.4mm, Dmin=8in, FL=12mm pixel=640*480

Then: FOVmin=6.4(8/12)=4.23mm 4.23/640=0.007mm

If the accuracy requirement is 0.01mm, 1pixels=0.007mm<0.01mm