Just got a used orion xt10... won't focus... SQUARE diffraction rings : r/ telescopes
PHYS 3650 Observational Astronomy Properties of Light and
Telescope Reviews. The most comprehensive guide to choosing a telescope, telescope designs and brands, Optics, Optical Quality, Aberrations, Recommended telescopes
Diffraction rings/Airy disk/Spherical Aberration for LX200 and etx90
Diffraction pattern and aberrations
Pushing Limits: A Spring Sky Double Star Romp - Sky & Telescope - Sky & Telescope
Diffraction in astronomy (and how to beat it!)
A typical pattern of diffraction rings illuminated by laser beam of λ =... | Download Scientific Diagram