Measuring with telecentric lenses

[greif1]

If I measure a flat object using a lens, projecting onto a flat CCD, is there any value to using a telecentric lens? Or will a high quality enlarging lens, etc. do just as well?

 

[DanStro]

I think that as long as your object and CCD are not tilted with respect to the lens a high quality non-telecentric lens will work just as well.

 

[IRstuff]

The main advantage of a telecentric lens:
> Object size is nearly constant for changes in object distance -- If you are making measurements, this might be a big issue. You can compensate by always having measurement reference in the image, but that might not always be possible.

> Depth of focus is larger, so refocusing for object distance changing is minimized



TTFN

FAQ731-376