Well, here are 2 versions of my photos taken last week.
Esprit 100
ASI 183MC-pro
50 frames to start
40 sec each frame
Gain 186
HEQ5 Pro unguided
No filters
Sharpcap
DSS
Processed very amateurishly in Pixinsight
I didn't know when to stop processing, so stopped when it looked not too bad, then did another slightly set of processing thingoes.
I have great difficulty sussing out that all the work you guys (who are experts) do, ends up in just a few lousy kilobites of a JPEG file.......Millions of pixels, hours of exposures, lights, darks, bias, then a zillion hours in processing the image, then all to turn all that huge amount of data into a 150kbite file
There must be something honourable and mighty you all do with that data?
ANYWAY here are two versions of my first half decent photo PLEEESE comment how I can make the images better
Great effort mate. I don't count myself as one of the " experts " you refer to but I do appreciate your work. Number 2 is better than number 1 in my humble opinion.
P.s. - you made me smile when you said about converting all the hours of data collection into a 150kb file. Big reality check, you're spot on !
"Millions of pixels, hours of exposures, lights, darks, bias, then a zillion hours in processing the image, then all to turn all that huge amount of data into a 150kbite file "
lol. Well analysed!
Many have an account on astrobin.com which accepts more bytes - but it's still in no relation to the amount of time spent and bytes produced before the end result
I like how you played around with the star count (assumably), making DSS detect less stars in the 2nd version. The star count in between both versions would be interesting to see, as well.
From the colour: I like both.
The stars in ver. 1 look more alive due to less clipping of the background.
Your detailed info on frames, gear, and processing is helpful. Did you take any darks?
I'm far from being an expert on digital astrophotography [as opposed to
film], but it would seem that your stars are bloated, and/or your focus
is a little bit off. I have attached one of my early [black clipped] efforts
to illustrate my point. I've just seen that it looks very ordinary downsized.
Best viewed at about 75% screen.
raymo
Last edited by raymo; 17-10-2018 at 07:39 PM.
Reason: more text
...but it would seem that your stars are bloated, and/or your focus is a little bit off...
No Ray, the 183 has a much smaller chip compared to a DSLR so you get half the field of view / double the magnification. It makes stars look fatter by comparison.
I'm only too happy to stand corrected, but those stars are more than twice the size that I would expect to see in an image, so I assume that there must be a way to correct the situation during processing.
raymo
Yes, I had to crop the jpeg a bit to try and reduce file size to 200kb. I opened with Microsoft Paint, then hit "resize" to about 70%. The full size jpeg I printed out on an A4 sheet of photo paper looks good to me, but I admit, the stars do look a little bloated!
How do you know, Silv, how much my star count was? Very interesting! Yes I think i played about with that percentage setting in DSS - I had problems a while ago when DSS got cranky and couldnt find enough stars.
I like your rendition, Karlzburg. I used that process module ATrous in PI which supposedly gets rid of noise, but maybe I will fiddle more with those sliders next time. I used what I read in a tutorial - ie layer1, 3.000, 0.62, iterations 2
layer 2, 2.000, 0.62, iterations 2
layer 3, 1.0, 0.62, iterations 2
layer 4, 0.500, 0.62, iterations 1
All a mystery to me what that all means
Thanks to you all!
Oh yes, I forgot to mention I did not use darks, bias or flats. I did use the cooling on the 183 - it said minus 15 deg C. I still cant get DSS to recognise adding darks, and on that photo, I tried stacking in PI. but it kept coming up with errors, so I did it in DSS
I used that process module ATrous in PI which supposedly gets rid of noise, but maybe I will fiddle more with those sliders next time. I used what I read in a tutorial - ie layer1, 3.000, 0.62, iterations 2
layer 2, 2.000, 0.62, iterations 2
layer 3, 1.0, 0.62, iterations 2
layer 4, 0.500, 0.62, iterations 1
All a mystery to me what that all means
Thanks to you all!
Noise reduction is best applied through a mask that protects the bright parts of the image (where the noise is already low.) A black clipped lightness mask is usually a good choice: extract lightness if you have a colour image, clip the blacks with HistogramTransformation, apply as a mask and then invert mask.
Thanks, Rick! I will give that a go. I have been frightened to look at masks and still not too sure. Something to do with the brown tab isn't it - then inverting etc. I got into a right pickle in Startools with a mask and haven't been game to try in PI. I'm only just fathoming out stacking using Batch processing in PI, so onwards and upwards as they say
PLEEESE comment how I can make the images better
