The long camera provides a field of view of 15 x 15 arc-min2, at a plate scale of 9 pixels/arc-sec, or 0.111 arc-sec/pixel. The camera consists of six all-spherical elements, arranged in a [1-3-1-1] grouping.
The design parameters for the long camera are:
field of view: 21.48 arc-min dia. 362 arc-min2
focal length: 641.79 mm (25.2675 inches)
scale: 0.111 arc-sec/px 9 px/arc-sec
0.0074 arc-sec/micron 135 microns/arc-sec
number of elements: 6
number of CaF2: 2
max. CaF2 dia.: 300 mm (12 inches)