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MattJenko

Unguided Andromeda galaxy from Kelling

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Here is my first effort at processing the vast amounts of data from Friday night at Kelling with some lovely skies for a few hours. TS60ED with an ASI1600 on a StarAdventurer. 229 x 30 seconds L and 90 x 10 second for each RGB, binned 2x2. Turned out rather nice. I threw away an awful lot of clouded out Lum subs, but my laptop was rather glad of that.

 

 

Andromeda_LRGB.jpg

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That's a fantastic image. Love the star colours as well. :) 

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That is rather lovely Matt, and with such a dinky little travel setup, albeit a top quality one. Glad you are getting some good skies. Just had a quick observe myself between scudding clouds, the rain has made it very transparent and a very still atmosphere too.

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Cheers Richard. Thanks Rob - the combination of short cmos subs, short focal length and mini mount does seem to work, much to my relief and happiness. Also, I took a rather large step in your footsteps and picked up an ex display RC6 at Kelling as well ;)

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36 minutes ago, MattJenko said:

Cheers Richard. Thanks Rob - the combination of short cmos subs, short focal length and mini mount does seem to work, much to my relief and happiness. Also, I took a rather large step in your footsteps and picked up an ex display RC6 at Kelling as well ;)

Fantastic, look forward to seeing it! :) 

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I think that's absolutely lovely.  The colour is spot on, to my eye anyway.  I'm amazed that you achieved such a great image from less than two hours of data ..... have I got that right?  

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..... I forgot to ask .... What did you use to process? 

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Thanks. There is just under 2 hours of Lum data and then 15 mins for each R,G,B channel, so the total integration time is 2.7 hours, so under 3 hours.

There are 0 calibration frames used in this. No flats, no bias, no darks. I used a Clone Stamp tool to remove a couple of dust artefacts.

Everything is processed in PixInsight - registering, stacking and post-processing.

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great image Matt and another + for the star adventurer

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I guess the ASI 1600 has proved itself--have you tried longer exposures...like 5-10 minutes.  I am thinking of using it for faint DSOs--narrowband nebula.  I understand that with 200+ subs, the high gain and 10/12 bit data smooths out and dynamic range is recaptured.  But how about longer subs, where so many subs are not likely--at 10 minute subs, 30-40 would be a good haul.

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WOW, that is an amazing result from just a heap of 30 second subs... 

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4 hours ago, Rodd said:

I guess the ASI 1600 has proved itself--have you tried longer exposures...like 5-10 minutes.  I am thinking of using it for faint DSOs--narrowband nebula.  I understand that with 200+ subs, the high gain and 10/12 bit data smooths out and dynamic range is recaptured.  But how about longer subs, where so many subs are not likely--at 10 minute subs, 30-40 would be a good haul.

5 min narrowband exposures works pretty well, although you have some amp glow to deal with when you do. Because the ASI is 14 bit, you also need lots of subs to get the dynamic range of a 16 bit CCD. For 5 min subs, you do start to require a lot of total integration time. When you do however, the results are great. Below is a 2 panel tri narrowband image of 6 hours per channel for about 38 hours total:

Heart_Soul_HST-X3.jpg

 

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8 minutes ago, MattJenko said:

5 min narrowband exposures works pretty well, although you have some amp glow to deal with when you do. Because the ASI is 14 bit, you also need lots of subs to get the dynamic range of a 16 bit CCD. For 5 min subs, you do start to require a lot of total integration time. When you do however, the results are great. Below is a 2 panel tri narrowband image of 6 hours per channel for about 38 hours total:

Heart_Soul_HST-X3.jpg

 

Looks good.  So for me, I have been taking 30 minute subs at f4.2 with an STT-8300 and 3nm filters.  With the ASI 1600, I think 10min exposures would be about right--maybe 8 min.  I think 5 might be a bit low,  so I would need allot of frames due to the 14 bit.  Right now I am taking 15-20 30 min subs per filter.  I am just trying to figure out if it will work.  I want it for the small pixels, it will provide the same FOV I get now at 2.06 arcsec/pix but it will give me 1.41 arcsec/pix.  Also--will 3nm filters work?  If it was 16 bit it would be a no brainer.

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Magnificent and spectacular images :)  I'm really looking forward to doing some serious imaging with this camera myself once I get sorted out :)

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Don't see why 3nm wouldn't work. Narrowband is not this cameras forte I would say, but it is doable, although really faint NB targets might be at the edge of possibility.

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That really is an astonishing M31 for the time and portable technology involved. As a Photoshop person I find myself positively twitching with the desire to give it a tweak here and there!!! It would be nice to lose those few spurious dark patches, for instance. But, blimey, a handy portable setup and - I had to read this twice before taking it in - 90 x 10 seconds per colour.

Gordon Bennett!

Olly

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11 hours ago, ollypenrice said:

As a Photoshop person I find myself positively twitching with the desire to give it a tweak here and there!!! It would be nice to lose those few spurious dark patches, for instance.

As a PixInsight user, I am curious as to how Photoshop can be used to address these? Also, I would advise purists and those prone to spluttering outbursts to skip this sentence, because the root cause of those dark patches is a complete lack of any calibration as I was too busy enjoying myself having clotted cream teas in Holt, chatting to new people and their remarkable solar scopes and drinking wine with friends to take them!

Edited by MattJenko
pedant

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5 hours ago, MattJenko said:

As a PixInsight user, I am curious as to how Photoshop can be used to address these? Also, I would advise purists and those prone to spluttering outbursts to skip this sentence, because the root cause of those dark patches is a complete lack of any calibration as I was too busy enjoying myself having clotted cream teas in Holt, chatting to new people and their remarkable solar scopes and drinking wine with friends to take them!

Very easy in Ps. You'd might make a bottom layer and open Curves. You'd put a marker on the line at the value of the healthy sky next to the mark, put in a couple of anchor points above that and then lift the part of the curve below them to brighten the dark patches. Then you'd erase the dark patches from the top layer and be burned at the stake by the Spanish Inquisition! Any residual dark pixels can be fixed using the clone stamp set to Blend Mode Lighten. This took three minutes on a screen grab. 

MattJ cosmetic.jpg

Better out than in, for me at least!

Olly

PS Bigamy rules. Or polygamy if you include such tempting lovelies as Registar and AstroArt...  I'll certainly be on the barbecue before the end of the week!!!

 

Edited by ollypenrice

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