It has been known for some time that, if curved legs rather than the usual straight ones are used in the spider that supports the secondary optics in certain telescopes, the visible diffraction effect is reduced. Fraunhofer theory is used to calculate the diffraction effects due to the curved leg spider. Calculated and photographic diffraction patterns are compared for straight and curved leg spiders.
© 1984 Optical Society of America
John L. Richter, "Spider diffraction: a comparison of curved and straight legs," Appl. Opt. 23, 1907-1913 (1984)