I see far too many vision applications that should use telecentric lenses but don’t. I imagine this is because: (a) telecentric lenses are expensive, and (b) not many people understand what telecentric imaging can do for them. I can’t do anything about (a) but I can help with (b).
Opto-Engineering have on their website a telecentric tutorial titled, “TELECENTRIC LENSES: BASIC INFORMATION AND WORKING PRINCIPLES” (the capitals are theirs). This does it exactly what it says, so I suggest everyone take a few minutes to expand their knowledge by clicking on that link.
I may set a test, so study hard!