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Iris Nebula during the summer slump- getting there!


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I have just completed a 3 day stint of imaging the iris nebula during these astro-dark devoid summer nights. The planets aligned and I got 3 nights in a row of clear skies, so I got red one the first, green on the second and blue on the last, due to my autofocuser having not arrived yet. It has come out quite nicely but I am missing a fair bit of data as setting my cam to cool at -10 or -20c caused the AR window to fog up after a certain amount of time, apparently in this 70%+ weather I can only do -5c at most. All in all I managed to get about 5 hours of exposure before the clouds and rain came back.

I'm quite pleased with the result, although I still have some work to do when it comes to either calibrating or background extracting properly, as I do have some odd colour gradients in the background that I had to fiddle around with post-RGB combination.

My guiding is still a little suspect in places, but having re-tightened the guidescope it did improve matters, so I suspect flexture is to blame. Either an OAG or a proper dovetail mounting for the guidescope+cam is in the future for this setup now.



I also re-processed to show the detail in the middle of the nebula better as well.

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Love it! Especially like the tight crop of the center. Makes the core feel "alive" and dynamic somehow.

1 hour ago, pipnina said:

my cam to cool at -10 or -20c caused the AR window to fog up after a certain amount of time, apparently in this 70%+ weather I can only do -5c at most.

Is this with the rising cam 571? Fitting a ZWO sensor window heater solves the issue, but actually no need to cool down so aggressively since the dark current produced is so low.

I have done some tests on mine and even at +10 it still takes 140s for every 1 electron of dark current per pixel to build up. Since astro darkness is out now, i reckon its safe to say you have enough sky brightness to swamp the tiny little dark signal to oblivion and back even from normally good skies and a much warmer sensor than you currently shoot at. At 0c the dark current buildup would be around 275s per 1e, at -5 its 510s per 1e and at -10 its a silly 1945s per 1e!

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