SECTOR STAR TEST CHART (36 SECTORS)

REFLECTANCE

The test chart consists of 9 sector stars, distributed equally over the picture area. The unresolved

center of the sector star is 10% of its outer diameter. Within the sector stars are two circular lines.

The inner one marks a 625 line structure, the larger circular line marks a structure of 312 lines.

The test chart is designed for

• adjustment of camera lenses

• checking back focal distance

• checking resolution over the picture area

With the aid of a low transmission filter and by means of low level lighting make sure that the

camera is not overmodulated with the aperture in the open position.

a) Optical focus: Adjust focus zoom lens at greatest focal length.

b) Back focus distance (lens): Adjust focus at shortest focal length by regulating lens

mechanically with adjustment screw and optimize alternatively with a).

c) Back focal distance (pick-up tubes): If focus varies from channel to channel between

greatest and shortest focal length, the individual pick-up tubes must be adjusted mechanically

in the optical axis.

1. Select white channel. Set optical focus at greatest focal length. With shortest focal length

and divergent focus adjust the pick-up tube in W-channel until optimum focus is achieved. If

necessary optimize by alternating with optical focus adjustment.

2. With unchanged optical focus adjustment and shortest focal length adjust the red and

blue pick-up tube until optimum focus is achieved. Image focus (focus adjustment) is maintained

at all focal lengths (zoom-in) and constant distance from object by means of back focal distance

adjustment.