Quote:
Originally Posted by davidpretorius
very interesting, I remember Stu's 5" tak with rings, but I am sure Asi, that I have never seen diffraction rings around stars when focussed in my 10"
doesn't it bugger up the view?
is it a certain magnitude star that shows up the diffraction rings?
ie does sirius show the brightest diffraction rings?
great thread by the way!
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Hi Dave
I find Sirius too bright so I use a mag 3 or 4 star but yes, Sirius would show very bright rings but there would be so much light in the centre dot, it could easily overwhelm the 1st or 2nd rings, especially in mediocre seeing.
In good seeing, I can see diffraction rings just slightly inside and outside of focus with my Vixen 4" refractor at x180 (5mm eyepiece) and My C9.25 at x235 (10mm eyepiece). They are certainly there at lower magnifications, and even more visible when you grossly defocus the image.
The attached image shows an example before the tube had cooled down.
Cheers
Dennis