The illumination system includes {HEAD ~ a light source} for producing a beam of parallel light, and optics for directing the produced beam through the telecentric lens system along the optical axis thereof, and through {TAIL ~ the hole} 
The illumination system includes { HEAD ~ a light source } for producing a beam of parallel light , and optics for directing the produced beam through the telecentric lens system along the optical axis thereof , and through { TAIL ~ the hole }
OTH OTH OTH OTH HEAD HEAD HEAD HEAD HEAD HEAD HEAD OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH TAIL TAIL TAIL TAIL TAIL TAIL