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Old 03-09-2021, 09:33 PM
Mickoid (Michael)
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A bit of an experiment

I wanted to see what NGC 6744 in Pavo would look like on a ZWOASI120MM sensor using a shorter focal length telescope. I married it up with a 550mm Esprit 100 but from where I was located, it was heading straight into city light pollution. I kind of gave up on it, from Bortle 6 skies it's just too faint to get much detail out of it. This is a stack of 10 x 70 seconds, for each RGB filter, plus 9 X 70 seconds using a multiband filter for Luminance, no darks or flats, unguided. You could hardly see any evidence of the galaxy on the subs to a point that I was wondering if I had moved to the target at all. I was amazed to see the spiral arms come out in post processing, so it wasn't a complete waste of time.

I ended up moving to NGC 253 and this is what it looked like, as with NGC 6744, there is a small amount of cropping to remove stacking artifacts but that was all I did, this is basically the whole sensor. I used a multiband filter and shot 10 x 70 seconds subs, darks, no flats, unguided on an HEQ5 mount. A bit of fun experimenting on a warmish Wednesday night here in Melbourne.
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Old 04-09-2021, 06:24 AM
Startrek (Martin)
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Mick,
Great effort on difficult targets under light polluted skies
Well done !!
Galaxies under these conditions can be successfully imaged with shorter focal lengths and smaller aperture scopes, you just need to image during new moon period , if using a OSC camera just an IR / cut filter or luminance filter and heaps and heaps of short subs
Here my image of NGC 1365 great barred spiral galaxy ( magnitude 9 ) from last year under Bortle 8 Sydney suburban skies and Neigbours lights blasting my yard using my 6” newt and 2600MC which just has a IR / UV protective window ( I used no other filter)
180 x 50 sec subs plus 20 darks
Stacked in DSS
Processed in Startools
Your images are a great start , keep at it , just more data is needed
Cheers
Martin
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Old 04-09-2021, 09:21 AM
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PKay (Peter)
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Good one Mick
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Old 04-09-2021, 05:55 PM
Mickoid (Michael)
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Quote:
Originally Posted by Startrek View Post
Mick,
Great effort on difficult targets under light polluted skies
Well done !!
Galaxies under these conditions can be successfully imaged with shorter focal lengths and smaller aperture scopes, you just need to image during new moon period , if using a OSC camera just an IR / cut filter or luminance filter and heaps and heaps of short subs
Here my image of NGC 1365 great barred spiral galaxy ( magnitude 9 ) from last year under Bortle 8 Sydney suburban skies and Neigbours lights blasting my yard using my 6” newt and 2600MC which just has a IR / UV protective window ( I used no other filter)
180 x 50 sec subs plus 20 darks
Stacked in DSS
Processed in Startools
Your images are a great start , keep at it , just more data is needed
Cheers
Martin
Thanks for the compliments and advice Martin and that's a great image of NGC 1365 from bortle 8 skies by the way. In this case I was just interested in the image scale on a 100/550mm telescope using the 120MMS sensor. I realise I needed many more subs to make these look more attractive but on this occasion that wasn't my goal, it actually wasn't a very good night to be out taking shots at all - windy and rather warm. The experiment achieved its purpose in showing how these objects will frame.

Quote:
Originally Posted by PKay View Post
Good one Mick
Thanks Peter, it's a start if I want to take this any further than wondering how these objects would fit in the frame using this set up.
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