The apparatus includes a telecentric lens system positionable at a near end of a hole with {HEAD ~ an optical axis} of the lens system aligned with the axis of the hole to image {TAIL ~ the interior} of the hole 
The apparatus includes a telecentric lens system positionable at a near end of a hole with { HEAD ~ an optical axis } of the lens system aligned with the axis of the hole to image { TAIL ~ the interior } of the hole
OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH HEAD HEAD HEAD HEAD HEAD HEAD HEAD OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH TAIL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH