reflectors articles
What primary optical defect do reflector telescopes largely eliminate compared to simple refractors?
What shape is the primary mirror typically ground in a Newtonian design?
At what specific angle is the flat, elliptical secondary mirror positioned relative to the optical axis in a Newtonian setup?
What is a frequent maintenance requirement for Newtonian reflectors due to their open tube design?
What characteristic defines the secondary mirror used in the standard Cassegrain configuration?
How does the Cassegrain configuration physically benefit observers compared to a Newtonian of the same focal length?
What is the primary optical benefit of the Ritchey-Chrétien system over a standard Cassegrain for wide-field imaging?
What optical element distinguishes the Ritchey-Chrétien system from the standard Cassegrain?
If the secondary mirror in a standard Cassegrain is not perfectly calculated for the primary, what specific aberration is likely to degrade star images?
What is the typical reflectivity percentage achieved by modern protected aluminum mirror coatings?