Calculate True Field of View, Magnification, and Optical Parameters
This calculator will estimate the field stop based on your eyepiece specifications and calculate all relevant optical parameters.
Dawes Limit = 4.56 / Aperture(inches)
The Dawes Limit estimates the theoretical resolving power of a telescope, representing the smallest angular separation at which two stars can be distinguished as separate objects.
True Field of View is the actual angular width of sky visible through your eyepiece.
Magnification is calculated as Telescope Focal Length ÷ Eyepiece Focal Length.
Exit Pupil affects image brightness and should generally be between 1-7mm for optimal viewing.
Relative Brightness estimates how bright objects will appear, with higher values indicating brighter views.