Light collecting power and obstruction

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In some cases it is of interest to check whether a refractor (lens telescope) is more efficient than a small reflector telescope with a secondary mirror.

Input of parameters for refractors (lens telescopes)
mm
mm
%
Resulting areas and diameters

Light collecting area of the telescope:          0 mm²

Equivalent light collecting area (taking into account the transmission):          0 mm²   (≙ D = 0 mm)

Input of parameters for reflectors (e.g. Newtonian) / catadioptric telescopes (e.g. SC)
mm
mm
%
%
Resulting obstruction (central shadowing by secondary mirror)

Area-related obstruction (describes the photon loss; A Secondary mirror * 100 / A Primary mirror):          0 %

Diameter-related obstruction (to illustrate the loss of contrast; linear specification: D Secondary mirror / D Primary mirror):          0 %
This specification has become established for planetary imaging. At values >30%, transitions are blurred / out of focus. (Image examples: http://www.damianpeach.com/simulation.htm)
Resulting areas and diameters

Light collecting area of the telescope (A Primary mirror - A Secondary mirror):          0 mm²   (≙ D = 0 mm)

Equivalent light collecting area (taking into account obstruction, reflectivity and transmission):          0 mm²   (≙ D = 0 mm)
Comparison of the effective light collecting areas from refractor to reflector

Light collecting area ratio (larger area / smaller area):          0

➥   0 0x 0

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