When coupling a LT CL series Telecentric illuminator with its compatible Telecentric lens, which change occurs in the Telecentric Lens field depth?
A. The use of a collimated source increases the natural field depth of the telecentric lenses by approx +20/30%, but that also depends on other factors such as the lens type, the light colour, the pixel size and the method used to compute field depth. Since the illuminator’s output N.A. is lower than the telecentric lens object N.A., the optical system behaves as if the lens had the same N.A. as the illuminator in terms of field depth, while maintaining the same image resolution as per the actual telecentric lens N.A. Q.
