I used 11X11 for ten cycles. It would most probably be different for the tiff. I would try 9x9 as well.
The good thing about RC telescopes is that the images they produce really only suffer from point spread function aberrations. That is Bessel Function due to diffraction. Gaussian is a good approximation for a Bessel Function at least for the zeroth order.
RC telescopes are as close to perfection as humans can make.
The good thing about RC telescopes is that the images they produce really only suffer from point spread function aberrations. That is Bessel Function due to diffraction. Gaussian is a good approximation for a Bessel Function at least for the zeroth order
Whatever this means Bert we believe you......where's that dictionery....lol
Thanks for the processing tips....we are always learning...thanks.
Hey Bert...where would you start with noise thresshold under the same settings....looks like default is 2 parts from the left...leave it their or adjust it.???
What that all means Tony that the original object ie a star is a point. When we image that point we get a diffraction pattern. If the aperture of the telescope is circular the diffraction pattern's intensity is in the form of a Bessel function. See pic below, recognize it?
Now all other points in an extended object (nebula) do exactly the same thing. Knowing this then the image we get can be deconvoluted to look more like the original. Because we know the mathematical relationships and with the power of modern digital computers,this is now a relatively simple exercise.
The planetary guys can get away with this with their Newtonians, as at the center of their optic the only aberration is diffraction. This is also why they collimate all the time! Further out they have coma due to spherical aberration.
RC optics don't suffer from this, a least over quite a good wide field.
Hope this makes sense. Just because I know a little (all right a lot) of science does not make me a teacher.
I forgot to mention, that as the aperture gets bigger, the central peak gets bigger in relation to the other peaks. The central obstruction in most common SC's and RC's puts more intensity into the secondary and tertiary diffraction rings and so on. That is why the refractor officionados are so so vehement about their chosen optic.They just simply ignore chromatic aberration.
There is no perfect optic. You use the best one for the job.
My 300mm lens cannot resolve what your 2500mm RC can. Your 2500mm cannot show as wide a field as my 300mm lens. We all take our pick.
That is why there is no point argueing. Make the best of what you have and push it to the limits.
Yeah, I'd say the one on the right is the original and the best; no dark rings around the foreground stars.
Just my opinion, and the original uncropped image is a beauty.
Hmmm jpeg artifacts?
here is a gif version sharpened with no dark halos. it is gif to get the file size down.
There werte no halos on the jpeg I downloaded from the supplied link.
Personally, I wouldn't want to sharpen an image as much as this, but for the sake of the exercise........................... .....
cheers,
Doug
Im going to set that image as my desktop wallpaper, as a reminder to stop goofing off on the PC, and pull my finger and finish the observatory, cant see a lot thru my lounge roof, and I cant move the scope without 2 others assistance, .
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