Top: The formation of a virtual image using a diverging lens. Bottom: The formation of a virtual image using a convex mirror. In both diagrams, f is the focal point, O is the object and I is the image, shown in grey ... Source Wikipedia
Top: The formation of a real image using a convex lens. Bottom: The formation of a real image using a concave mirror. In both diagrams, f is the focal point, O is the object, and I is the image. Source Wikipedia
In an imperfect lens L, all the rays do not pass through a focal point. The smallest circle that they pass through C is called the circle of least confusion. Source Wikipedia
This is a major advantage for solar telescopes, where a field stop (Gregorian stop) can reduce the amount of heat reaching the secondary mirror and subsequent optical components. Source Wikipedia
In the Gregorian design, the primary mirror creates a real image before the secondary mirror. This allows for a field stop to be placed at this location, so that the light from outside the field of view does not reach the secondary mirror. Source Wikipedia
The classic Cassegrain telescope has a parabolic primary mirror and a hyperbolic secondary mirror Gallery Tutorial TRAIL: Webel SysML Parsing Analysis example: Optical telescopes from Wikipedia: Structure and port-based light flow model Section Slide kind SysML Block Definition Diagram (BDD)
The Newtonian telescope has flat secondary mirror and a paraboloid or spherical primary mirror Gallery Tutorial TRAIL: Webel SysML Parsing Analysis example: Optical telescopes from Wikipedia: Structure and port-based light flow model Section Slide kind SysML Block Definition Diagram (BDD)
In optics, the f-number of an optical system such as a camera lens is the ratio of the system's focal length to the diameter of the entrance pupil ("clear aperture"). It is also known as the focal ratio, f-ratio, or f-stop Source Wikipedia
The Gregorian telescope employs a concave secondary mirror that reflects the image back through a hole in the primary mirror. Gallery Tutorial TRAIL: Webel SysML Parsing Analysis example: Optical telescopes from Wikipedia: Structure and port-based light flow model Section Slide kind SysML Block Definition Diagram (BDD)
A curved primary mirror is the reflector telescope's basic optical element Gallery Tutorial TRAIL: Webel SysML Parsing Analysis example: Optical telescopes from Wikipedia: Structure and port-based light flow model Section Slide kind SysML Block Definition Diagram (BDD)