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First Light on Autoguiding w/ MGEN II

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#1 AKHalea

AKHalea

    Mariner 2

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Posted 20 March 2017 - 10:35 AM

I finally got my new standalone Autoguider Lacerta MGEN II to work with my Nikon DSLR. I shot the Rosette nebula last night with the guidecam attached to an Orion 9x50 guidescope. The autoguider also controlled my unmodded Nikon (with the right cable attachments bot separately). This is the first time I also used RD function (Random Displacement or Dithering). Here is the image I managed to get:

 

3-19 Rosette STCrIsoJ1.jpg

 

This was shot with my 80ED refractor (f7.5) and Nikon D5200 DSLR from my orange zone suburban backyard. No LP filter was used. Integration time was rather short as the nebula started going into the nearby city's LP dome after I took 48x120 sec subs (ISO 400). I used flats & bias calibration frames, but no darks. I used DSS for stacking & StarTools for post processing to remove LP & vignetting.

 

While I understand that total integration time is short, I thought I should get more detail. Perhaps I am not doing the post processing correctly. Maybe some of you might want to try your hand at the tiff file straight out of DSS (copied below) : 

 

https://www.dropbox....ette T.TIF?dl=0

 

Would an LP filter help? I would appreciate any feedback you can give me in terms of what I can do better. Thanks ..... Anil


Edited by AKHalea, 20 March 2017 - 10:44 AM.

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#2 AKHalea

AKHalea

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Posted 21 March 2017 - 08:46 PM

Hmmm. I guess the image is rather uninspiring, but I was hoping a few would try their hand at processing the linked tiff file. Let me know how that goes if you try. Thanks ..... Anil



#3 cyber

cyber

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Posted 23 March 2017 - 08:14 AM

The stars in the center of the image look good, so your auto-guiding seems to be working fine.

However, the major issue with this image is uneven illumination.

The image still has dust motes and huge reflections near the edge.

 

This autostretch of the data with only a color correction in the WIPE module, clearly shows the problem:

 

AKHalea rosette.JPG

 

Can you try to stack without any calibration frames? Maybe something went wrong with the flats.


Edited by cyber, 23 March 2017 - 08:16 AM.


#4 AKHalea

AKHalea

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Posted 23 March 2017 - 08:03 PM

Thanks for your response and taking the stack and processing it. I know the image has many dust motes even though I have tried to keep the optics as clean as possible. Springtime has its own perils in AP! Also, I used flats from the flat file library. I had figured old flats might be OK to be used, but the dust motes appear randomly and can change positions, so that was not such a hot idea.

 

I tried stacking without flats (& bias frmaes). There is amp glow, more severe vignetting and the dust motes are still there. So, lesson learned - must take flats every time! .... Anil




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