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Finally i did something decent in EAA - NGC 2438 - Planetary nebula 12" f/5 GSO Dobsonian


Tiago Ferreira

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YES! After a while with loads of fails each time i went with sharpcap live stack, today i finally managed to do something to start with.

This is the beginning, the night i've live stacked something.

It's been hard to figure live stack tricks, many things at the same time.

This was my image. OMG this jumped in a few seconds. No boring processing waiting, just point, live stack and finally SEE something fast stacked.

I also tooked a print screen hoping that you can help me to figure what i should change based on what you see. Please find it below and give me some hints for me to proceed.

I've noted when playing with histogram that half of the screen was brighter than the other half, not uniform.

The picture was "save as seen" in png

NGC 2438 - Planetary nebula

12" f/5 GSO Dobsonian
Geoptik Eartha Equatorial Platform
ZWO ASI224MC
Baader IR/UV cut L-filter
TS 0.5x Reducer spaced to 0.7x

117 frames
Gain=500
Exposure=1

Stack_117frames_117s_WithDisplayStretch.thumb.png.468f78cb4a3e3fdf09e1f19d045065d1.png

eaaprint.jpg

Edited by astrocanito
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  • 2 weeks later...

Hi

First of all, congratulations on your first live-stacked image. It gives a fine view of the PN and one that you will remember in days to come long after you have honed your skills further.

I'm fairly new to SharpCap too so please don't think that the following is in any way authoritative. You say that half of the screen was brighter than the other half. There could be a number of reasons for that including the possibility that stray ambient light was entering the telescope's view from off to one side. But the thought that more immediately comes to mind is that you may not have been using a flat-field image when doing your live stack. The right hand side of your screenshot of SharpCap's display does not extend down far enough to see if you were using a flat in the preprocessing section. If not, you would be well advised to try that. Doing so is quite easy – there are many articles on the internet showing various ways to set your telescope up to take flat images. In SharpCap you use the Capture menu to select Capture Flat … and then follow the simple instructions given there.

I hope that this helps. Keep up the good work.

David

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yeah not always happen which make me think it can be some intrusive subtil light. i can't  remember. i am aware about flats but i am too lazy to do that. i am working now only with darks to see how it goes. darks i don't like but i don't mind to capture but flatsare too boring for me to do.

18 hours ago, AusGuy said:

Hi

First of all, congratulations on your first live-stacked image. It gives a fine view of the PN and one that you will remember in days to come long after you have honed your skills further.

I'm fairly new to SharpCap too so please don't think that the following is in any way authoritative. You say that half of the screen was brighter than the other half. There could be a number of reasons for that including the possibility that stray ambient light was entering the telescope's view from off to one side. But the thought that more immediately comes to mind is that you may not have been using a flat-field image when doing your live stack. The right hand side of your screenshot of SharpCap's display does not extend down far enough to see if you were using a flat in the preprocessing section. If not, you would be well advised to try that. Doing so is quite easy – there are many articles on the internet showing various ways to set your telescope up to take flat images. In SharpCap you use the Capture menu to select Capture Flat … and then follow the simple instructions given there.

I hope that this helps. Keep up the good work.

David

 

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