P120FB02: repeat at 4:1 with target moved from focal plane to near contact with first surface of lens 1. Outer dark green/dark cyan is the Stop. The dark gray "circle" is the interior wall of the Stop. The Target is red, white, blue, green 10 mm squares (20mm square total width). The yellow/magenta at the left of the Stop is the surface of the Pick- off mirror. The orange at the top is the Filter Housing.