Willstrop telescope

Willstrop telescope

Willstrop telescope

(wil -strop) A compact three-mirror telescope with a very wide field of view, designed by Roderick Willstrop (see illustration). The focal plane lies at the center of the perforated primary mirror, which is approximately paraboloidal. The convex secondary and concave tertiary depart from sphericity. The system produces a high-quality image with very low image spread.