relative luminosity การใช้

Ground mounted signals are rarely so critical for alignment ( hence ground mounting ) and are often used in tunnels where the relative luminosity of the aspects are much higher.
Deriving the relative luminosities of the two components from the profile of the O VI resonance line gives a luminosity of for the primary, but this would imply an unreasonably low temperature.
That seems a bit too strong, since it's linear speed, distance, direction, relative luminosity, and size all play a part . talk ) 17 : 29, 3 October 2014 ( UTC)
Typically objective lenses on early sights are smaller than modern sights, in these examples the 4?1 would have an objective approximately 36mm diameter and the 2.5?0 should be approximately 21mm ( relative luminosity is the square of the exit pupil as measured in mm; a 36mm objective lens diameter divided by the 4x magnification gives an exit pupil of 9mm; 9x9 = 81)