Quote:
Originally Posted by Satchmo
To guarantee optical and mechanical quality. 0.5 wave spherical aberration plus a 50% obstruction will probably have an Encircled Energy Ratio ( the Strehl value taking into account obstructive effects ) of less than 0.5... A low Strehl value does not render a telescope useless for imaging. Most of the worlds large RC's probably have 50% obstructions...their resolutions even with large obstruction are way below the seeing limit anyway.
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Hi Mark,
Thanks for that information.
Is there an online calculator which can provide an
Encircled Energy Ratio
& a
Strehl ratio for a given system - in theory assuming that it was perfect?
This is a link for an online calculator
http://www.wilmslowastro.com/software/formulae.htm
but it doesn't show the above calculations.
cheers
Allan