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...thanks for your feedback, Mike, Lee, Jase, Dennis, Rob, Felix, Ric
n' Nick.
to add all information I want to continue...
last year I acquired the frames in SX original software, applying some slight streching filters to them and color converting them before sorting them as 16 bit tiffs. these were aligned in images plus not using a dark frame or a defect map.
single frames were 2, 4 and 6 min subs...much too short - but I did not know that better...
the displaying mode in SX original software is somewhat different to astroart...in astroart you can read the "counts" telling you, what is perfectly exposed and what not - so this way you can find out the perfect exposure time for each object - or for star colors:
I did not have astroart4 at this time...
my processing knowlege and skill has "changed" over the time now...
this year I acquired the images in astroart (automatic routione while I am spleeping in the obs...(- and storing all files as 16 bit FITS.
preprocessing is sone in astroart including a defect map - but no dark...
reamining hotties werre eradicated by a global /r,g,b median filter)
this comparsion is not thought to be a highly sophisticated scientific study - it is more like comparing apples with strawberries,...but I wanted to demonstrate the "over all" difference...
anyway:
conclusions for me:
~10 min subs are very good for starcolors in my slow system
~a defect map is a handy feature to work the small amount of hotties you will get with this nice sony-color chip...the remaining hotties can be erased with a median filter (loss of stars possible...?)
~exposure time like 2-5 minutes is too little to gather data in faint objects
~preprocessing in AstroArt4 is much more powerful than in SX original software
~background improves a lot with increasing number of exposures that have a reasonable single exp time
~exp time less than (let`s say) 5-6 minutes in galaxy-like objects even lots of frames can not bring up faint structures.
good luck to all!
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