To determine the exact lens you need for your specific application, follow next steps :
• Measure the Field of View ( size of the image you need )
• Measure the working Distance (WD) - This is the distance between the top of the lens and the object.
• Look into the specs of the camera to find out which size of CCD chip they use ( 1/3 inch - 1/2 inch - 2/3 inch etc...)
Example Calculation Focal Length CCD chip ( also called sensor ) 1/3 inch with C-mount as mostly used on microscopes. The Working Distance is 200 mm The object size, is 30 mm ( Field Of View) Convert all sizes to mm ( 1 Inch is 25.4 mm )
Formula : FL = CCD x WD/FOV
Calculation in mm:
FL = 4.8 mm x 200 mm / 30 mm
FL = You need a 32 mm lens.
C-Mount Lenses for Megapixel Camera's
1/4 " Horizontal 3.2 mm - Vertical 2.4 mm 1/3 " Horizontal 4.8 mm - Vertical 3.6 mm 1/2 " Horizontal 6.4 mm - Vertical 4.8 mm 2/3 " Horizontal 8.8 mm - Vertical 6.6 mm 1" Horizontal 12.8 mm- Vertical 9.6 mm
Motorized Zoom lenses
Fixed-Focal Lenses
High Resolution Lenses