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Using obstructions during startest simulation
This page is made especially to show that the using the exact percentage of your telescope’s obstruction during simulations is very important. If you for instance want to compare a 1/8 Lower Spherical Aberration (LSA) for a 33% obstructed telescope you should not use 30% or 35% obstruction.

Why : look at the differences below !

Picture

30% Obstructed +1/8 wave LSA at 10 wave defocus

Picture

33% Obstructed +1/8 wave LSA at 10 wave defocus

Picture

35% Obstructed +1/8 wave LSA at 10 wave defocus

Markings

A: at this point the diffraction images of both 30% and 33% do show a pair of dark bands. These bands are nearly missing in the 35% image.

B: Especially the 33% image shows a clear bright ring in this position. This rings is less prominent in the 35% and missing in the 30%

C:A clear bright ring in both 30% and 33% that is missing in the 35%.

D: a dark band that is most prominent at 35% and 33% but clearly less at 30%

 

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