Ags

What problem are you having accessing the source code?

It took all day, but I calculated the diffraction patterns of 20 different telescopes (mostly variations of Newtonian). It's too late to upload all the results, but I did make a start on publishing the pictures of the diffraction patterns: http://opticsandalgorithms.blogspot.nl/2015/04/refractor-diffraction-patterns.html

Yes, firstly I was relieved when my simulator matched the Rayleigh formula for refractors, and also that it showed the slight resolution boost obstructed instruments enjoy :-)

No, the Rayleigh criterion is simply miscalculated for scopes with a central obstruction. The formula typically given for the Rayleigh limit applies specifically to refractors, which have more energy in their airy disc, but it is slightly broader than the same disk in an obstructed telescope.

The convention is to use the peak sensitivity of the human eye which is ~510nm at night. http://en.m.wikipedia.org/wiki/Spectral_sensitivity At higher frequencies, the Airy disc gets smaller. I think observers in the 18th century noted color fringing in diffraction rings.

I've had a thread going in the Physics section for a few years regarding diffraction and Airy discs. I was trying to calculate telescope resolution and contrast for different optical designs. I eventually cracked the problem and spent today feeding some telescopes through my simulator. Because a lot of work has gone into this, and it needs more explanation than a forum post allows, I set up a blog for myself. http://opticsandalgorithms.blogspot.nl/2015/04/calculating-diffraction-patterns.html At the bottom of the page you can find a table of various telescopes and their resolutions and contrast levels for different targets. Of course even if my maths is perfect (and I can't believe my lovely SE4 comes out as badly as it does) I do not take into account manufacturing errors, so my results may be more applicable to high-end instruments like TMB apos than more affordable instruments like an ST80.

Spaceboy... you have too many EPs! Are those all filled with Naglers?