I don't use primary optics which are not made by myself.
48 Is the moon only 60 pixels? may 9 '14
25 Why is the Eagle Nebula so “static”? jan 6
18 Did we ever actually see the earth revolving around the sun? Is the geocentric model completely disproved? may 29 '14
12 First night on a telescope questions apr 19 '14
9 Why does a mirror bent 'like a potato chip' allow space telescopes to be smaller and have a wider field of view? nov 6
9 Can magnetism escape a black hole? jan 12
9 Do moons have moons? may 1 '14