- Define the task – Is it presence/absence, dimensional gauging, or surface defect detection? Each demands different resolution.
- Map the FoV – Measure the largest part to be seen; add clearance for robot grippers or fixtures.
- Match sensor & focal length – Use a lens calculator to hit the required FoV at your WD without cropping.
- Budget resolution – Pixels ≥ 2× the smallest defect obey the Nyquist rule; pick glass whose MTF supports that spatial frequency.
- Stress-test lighting – If you must stop down for depth-of-field, verify that illumination still saturates the sensor.
Pro tip: keep a “test lens kit” (wide, normal, tele, plus one telecentric) in your lab—hands-on trials beat spec-sheet hunting.
