Description

Comprising a convex lens 38 mm diameter & 150 mm focal length, mounted in a plastic tube 400 x 50 mm diameter, & a double convex lens 50 mm diameter & 500mm focal length, mounted in a tube 400 x 55 mm diameter. The smaller tube is located in the large tube my means of foam plastic rings which provide an effective sliding light seal, with plano concave eye piece lens to provide erect image…..