Calculator for Newtonian telescopes
(Please enter All Dimensions in inch or mm)
   
Primary Diameter    
Primary Focal Length (F1+F2)    
Internal Tube To Focal Plane (F3)    
Secondary to Front Tube (F4)    
Extra diameter on front Aperture for devergence Beams    
Full Illuminaded Field of View (Arcminute)
Circle Diameter of FOV (FP1)
Secondary Diameter
Tube Internal Diameter (D2)
Secondary ToFocal Plan (F2)
Secondary To Primary Mirror (F1)
Secondary Offset
FOV from Front Aperture (ArcMinute)
Circle Diameter on focuser base
From drop-down list choose:
A. "Secondary Diameter" if you already have the fixing diameter of secondary and need to calculate the Full Illuminated Field of View corresponding to the secondary diameter you entered.
B. "Full illuminated field" if you have decide the Full Illuminated Field of View you wish and need to calculate the secondary diameter in order to have the desired FOV you entered.
The program will calculate the Frond Aperture Diameter (Tube Internal diameter) needed to have the desired FOV but sometimes ATMs need an extra diameter to prevent loss of Illumination at the edge of the field.
In these case put the extra diameter in the text box (Extra diameter on front Aperture for divergence Beams) and the program will estimate again the Full illumination field that result from the summary of the frond aperture diameter. In this case the Full Iluumenated Field of View and FOV from Frond aperture will be diferent.