Hemisphere:  Northern  ·  Constellation: Andromeda (And)  ·  Contains:  Andromeda galaxy  ·  Great Nebula in Andromeda  ·  M 110  ·  M 31  ·  M 32  ·  NGC 205  ·  NGC 206  ·  NGC 221  ·  NGC 224
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M31, 



    
        

            Linda
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Getting plate-solving status, please wait...
M31, 



    
        

            Linda
Powered byPixInsight

Imaging telescopes or lenses: Stellarvue SV80-3SV

Imaging cameras: ASI294MC Pro

Mounts: Losmandy GM811G

Software: Pleaides Astrophoto PixInsight 1.8 Ripley  ·  Sequence Generator Pro

Accessory: Pegasus Astro Pocket Powerbox  ·  Dew-Not DN004 Dew Heater Strap  ·  Losmandy Lightweight Tripod  ·  Goal Zero Yeti 400


Dates:Dec. 18, 2018

Frames: 621x15" (2h 35' 15") (gain: 120.00) 0C

Integration: 2h 35' 15"

Darks: 100

Flats: 100

Bias: 500

Avg. Moon age: 10.23 days

Avg. Moon phase: 78.49%


Astrometry.net job: 2459416

RA center: 0h 42' 19"

DEC center: +41° 18' 25"

Pixel scale: 1.963 arcsec/pixel

Orientation: 116.924 degrees

Field radius: 1.138 degrees


Resolution: 3463x2330

Locations: Home, Broadlands, VA, United States

Data source: Backyard

Description

I've been having tracking issues with my mount that I'm still trying to track down so I thought I'd try an experiment in short exposure photography. This was 621 frames with 15 second exposures at gain 120 on an ASI294MC Pro.

Overall it worked better than I expected. It looks like my focus creeped a bit while I was sleeping (really need to get some automated focusing going) and the background looked a bit blotchy after running DBE but I was able to keep it under control for the most part.

I tried to be fairly gentle in the processing:

DBE

PCC

Luminance and chrominance noise reduction with MLT

iterative HT stretching

saturation boost with Curves (using a mask to not saturate the background)

mild LocalHistogramEquilization for some contrast enhancement

I really didn't want to do this with a nearly full moon in the sky but between a crazy work schedule and a record breaking year for rain there haven't been many opportunities in the last couple of months. I figured the experiment had value even if I didn't get anything useful from it. As it turned out, it was better than expected. Going to try using slightly longer exposures or higher gain or both to see if there is a sweet spot.

Constructive criticism always welcome.

Comments

Revisions

  • M31, 



    
        

            Linda
    Original
  • M31, 



    
        

            Linda
    B
  • M31, 



    
        

            Linda
    C
  • M31, 



    
        

            Linda
    D
  • M31, 



    
        

            Linda
    E
  • Final
    M31, 



    
        

            Linda
    F

B

Description: I ran PI's Dark Structure Enhance using default settings to help bring out the dust lanes a bit. Seems to help a bit.

Uploaded: ...

C

Description: This is a reprocessing that eliminates the background splotchiness and (mostly) tames the complex gradients.

Uploaded: ...

D

Description: A bit of cropping to remove some gradient edges.

Uploaded: ...

E

Description: A hopefully final revision. Ran the dark structure enhance script and shifted the color balance slightly warmer. It was coming across a bit harsh in the previous revision.

Uploaded: ...

F

Description: With the weather not cooperating, I decided to revisit this and see if I could do better. My goals were to minimize the background blotchiness and maximize detail in the galaxy. I may have pushed it a bit too far. What does everyone think?

Uploaded: ...

Sky plot

Sky plot

Histogram

M31, 



    
        

            Linda