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M31 First Light for...Everything!

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#1 Kriz1027

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Posted 18 September 2019 - 12:09 AM

Well, we will see how this goes with first light using new ASI1600 PRO & Filter Wheel, first time guiding using PHD2 and first time using SGP.  So far so good with decent guiding at around .60 RMS after the first hour and SGP is sequencing and auto focusing perfectly.  Hopefully the meridian flip will work and the moon will not impact the images too much.  Time to go to bed, we will see what I have in the morning.

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Edited by Kriz1027, 18 September 2019 - 12:09 AM.

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#2 jerahian

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Posted 18 September 2019 - 01:37 AM

Great work getting it all to hum along!

 

I do want to point out though, assuming I'm reading this correctly since I haven't used SGP for a while, your mean & median ADU is super high.  You're compressing your dynamic range towards the upper limit, and getting some significant saturation clipping with your 300s Lum.  Even though your image looks somewhat OK (galaxy core seems blown out), your histograms are telling a different story.  You might want to do 60s Lum to keep that histo peak as far left as possible.

 

Like I said, I'm hoping I'm reading the SGP stats correctly or, more precisely, I'm hoping I'm wrong.  I guess you'll find out in the morning...

 

-Ara


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#3 happylimpet

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Posted 18 September 2019 - 05:45 AM

Great its all working! But I would second the above....

 

I was going to point out that you could check to see if the recent bright nova is visible in your images:

 

https://www.flickr.c...06/48735063736/

 

but if theyre saturated as they appear it's lost in the core.


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#4 Kriz1027

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Posted 18 September 2019 - 07:46 AM

Well, that’s a bummer...looks like I’ll be reshooting tonight with shorter exposures. Aside from my exposure error everything else ran great and the scope was parked as it it should be this morning.

AP really is a trial by error process, hopefully I’ll work through the errors quickly and start taking some decent images soon.

Thanks for the heads up on the clipping issue, I’ve still got a lot to learn!
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#5 jerahian

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Posted 18 September 2019 - 12:10 PM

Well, that’s a bummer...looks like I’ll be reshooting tonight with shorter exposures. Aside from my exposure error everything else ran great and the scope was parked as it it should be this morning.

AP really is a trial by error process, hopefully I’ll work through the errors quickly and start taking some decent images soon.

Thanks for the heads up on the clipping issue, I’ve still got a lot to learn!

If you’re going to retry, make sure to also check the gain and offset values for your camera.  For the 1600MM Pro, the often used  values for LRGB are gain of 75, offset 15.

 

Also, last night was not a waste.  You probably picked up some faint details on the outer perimeter of M31 with your long exposures.  You can then do an HDR composite with PixInsight if you target your next set of images to properly expose the core of the galaxy.  If you haven’t done HDR composites before, you can follow along this tutorial from Kayron’s fantastic Light Vortex Astronomy site:  https://www.lightvor...-hdr-image.html

 

Do please share your final image when you have it.  I’d love to see how it turns out.

 

GL&CS,

Ara


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#6 Kriz1027

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Posted 18 September 2019 - 01:23 PM

If you’re going to retry, make sure to also check the gain and offset values for your camera.  For the 1600MM Pro, the often used  values for LRGB are gain of 75, offset 15.

 

Also, last night was not a waste.  You probably picked up some faint details on the outer perimeter of M31 with your long exposures.  You can then do an HDR composite with PixInsight if you target your next set of images to properly expose the core of the galaxy.  If you haven’t done HDR composites before, you can follow along this tutorial from Kayron’s fantastic Light Vortex Astronomy site:  https://www.lightvor...-hdr-image.html

 

Do please share your final image when you have it.  I’d love to see how it turns out.

 

GL&CS,

Ara

I am using 76 Gain and 15 offset (must of hit 6 instead of 5 by mistake).  Thanks for the suggestion on the HDR composite, I'll give that a try.  I will redo the Lum tonight and get additional RGB data and then start learning Pixinsight.  Might have something to look at by the end of October based on my current learning curve.


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