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gnomus

M31 - 'Read The Manual' - Rework of December Data

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I have been generally pleased with my Moravian camera and filter wheel.  However, I noticed I was getting some very odd results when trying to calculate filter offsets for my autofocus routine.  I found that the wheel was not rotating to the filter requested - indeed it seemed random.  Of course it was not random ....  

I have a 10 position filter wheel.  However, it seemed that the Moravian Ascom driver was convinced I had a 12 position wheel.  To get the Moravian wheel correctly configured, you have to run a configuration program.  It tells you to do this in the manual.  I just hadn't read the manual.  As you can imagine, this led to erratic results.  If I shot filters in sequence, things would go OK.  However, if I tried to go back to a filter I had shot before then it would not work.  Now, I shoot the flats from my 7 filters all in one go, BUT I test out the required exposure times first which means a cycle through all 7. So when I come to shoot the actual flats, I am shooting through the wrong filter or (sometimes) through no filter at all.  

I was never all that happy with the M31 I did back in early December 2016.  There seemed an odd gradient on the left side of the image: https://stargazerslounge.com/topic/282827-m31-revisit/  So, having got the wheel correctly configured, I redid the flats and recalibrated the data.  Lo and behold,  the bright patch on the left disappeared.  

Data:

Baader Blue 36 mm: 16x300"
Baader Green 36 mm: 16x300"
Baader Luminance 36 mm: 61x300"
Baader Red 36 mm: 16x300"
Chroma Ha 3nm: 6x1200"

0A_HaLRGB_Combo_Finx1920.jpg

Edited by gnomus
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Excellent! It's almost worth the pain of things not working properly to experience the delight when they finally do.

This one almost requires sunglasses, the colours are intense!

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Yes the colours are very striking. Great image :) 

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Beautiful image.

A fairly obscure problem that must have led to some hair-tearing before it was discovered. Sometimes the need for meticulousness overwhelms me. It doesn't sit well with my general seat of the pants, suck it and see approach!

Whether its hardware or software, we really do have to spend the time figuring out how it all works - sadly!

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Stunning and well balanced with all the detail preserved in the core!

It reminds me of the recent thread here that ended in a discussion of how much we were "allowed" to compress the dynamic range in order to show detail in both the dark and light areas. I am for total freedom there, and clearly M31, like M42, cannot be made pretty if we do not suppress the light in the brightest parts. Did you manage this without any shorter subs for the galactic centre?

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That's really nice Steve, i think a little more brightness night help with the highlighting of detail but that is being over picky.  Nice work Paddy

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7 hours ago, PatrickGilliland said:

That's really nice Steve, i think a little more brightness night help with the highlighting of detail but that is being over picky.  Nice work Paddy

A bit brighter....  (and less Acid house):

B_HaLRGB_LCE_Finx1920.jpg

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Fantastic image.  I've just followed the links all the way back to your first image of M31.  You've made fantastic progress over the years. 

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24 minutes ago, Ouroboros said:

Fantastic image.  I've just followed the links all the way back to your first image of M31.  You've made fantastic progress over the years. 

Thank you.  Did you really go ALL the way back? If so, I apologise for any distress caused by what you found.....  https://stargazerslounge.com/topic/230301-is-this-a-focus-or-dew-problem/?do=findComment&comment=2488473 

 

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Nice image (now)!

The worst aspect of astrophotography is that it's so difficult to get everything right.

The best aspect of astrophotography is the exhilaration you feel when you do get everything right!

If all else fails I tend to read the manual too.

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15 minutes ago, gnomus said:

Thank you.  Did you really go ALL the way back? If so, I apologise for any distress caused by what you found.....  https://stargazerslounge.com/topic/230301-is-this-a-focus-or-dew-problem/?do=findComment&comment=2488473 

I did! I'm now lying down in a darkened room. Only joking! :) It's very encouraging to someone like myself who is about a third way along the journey you have made. 

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57 minutes ago, Petergoodhew said:

....

If all else fails I tend to read the manual too.

Yes, but I always feel a sense of shame afterwards.....

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That's looking really nice Steve - I prefer the second slightly lighter edit :)

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Even better, version two is lovely. As for the thread with your first attempt, superb! Amazing what many thousands of pounds and a couple of years of making mistakes can do. Well worth every penny and every 'doh'!!

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Cool I was right (don't tell the other half she would not believe that statement :) ) I like second version more.  Looking back at that old image shows how well you have progressed, though I look back at those days myself and recall the excitement when that data first came down, it was a different experience altogether and one worth having.  Trying to be better all the time does become rally hard work :) 

Paddy

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Nice write-up Steve and a telling story that makes us all chuckle as we recognise our own behaviours and experiences.  Version two for me - wonderful.

Edited by Barry-Wilson

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