Jump to content

  •  

CNers have asked about a donation box for Cloudy Nights over the years, so here you go. Donation is not required by any means, so please enjoy your stay.

Photo

2024 Total Solar Eclipse (HDR)

Astrophotography
4 replies to this topic

#1 KBALLZZ

KBALLZZ

    Vostok 1

  • *****
  • topic starter
  • Posts: 161
  • Joined: 28 Dec 2015

Posted 09 May 2024 - 03:09 PM

53709842986_83c2e28c8a_b.jpg

 

2024 Total Solar Eclipse (HDR) by Andrew Klinger, on Flickr

 

This high dynamic range view shows off the intricate coronal detail that can only be observed during a total solar eclipse. The corona can be seen as long streamers reaching towards the edge of the frame as well as the loops and plumes closer to the sun's surface. They are affected by the sun's magnetic field which induces the twisting shapes and loops. Furthermore, the prominences (bright pink loops of plasma) can also be seen affecting the coronal structure. The charged particles that make up the corona have so much energy that they leave the sun's gravitational pull and become known as the "solar wind" contributing to phenomena such as auroras. The sun is currently in the peak of its solar cycle (i.e. solar maximum) causing an insane amount of coronal activity compared to the 2017 eclipse.

 

The moon is not a composite from a different image. It is illuminated by the light reflected off of Earth (i.e. Earthshine) and the features were barely captured in my 2" exposures.

 

Because a total eclipse ranges from uncomfortably bright to barely brighter than the background sky I had to capture exposures as short as 1/1000sec and as long as 2sec. We had a clearing of clouds for the last minute of totality and I was able to capture about 4 of these exposure loops.

 

To create this image I had to combine about 40 of these individual exposures. It is a unique task poses completely different problems when compared to deep space imaging. More info on that in the processing notes.

 

Observed and imaged on April 8th, 2024 from Joshua, TX. (Totality of 3min 4sec)

 

Processing notes and high res: https://astrob.in/j7hj95/0/

 

Equipment:
OTA: William Optics GT81 (478mm fl at f/5.9)
Mount: Orion Sirius EQ-G (HEQ-5)
QHYCCD PoleMaster

Imaging camera: Canon 6DmkII (unmodified)

 

Software:
EQMOD
SETnC (automated camera control for eclipse imaging)

PixInsight

 

Acquisition:
ISO100
4 x 1/1000"
4 x 1/500"
4 x 1/250"
3 x 1/125"
3 x 1/60"
3 x 1/30"
3 x 1/15"
3 x 1/8"
4 x 1/4"
4 x 1/2"
3 x 1"
3 x 2"
Total integration time: 12.777"
30 darks per exposure bracket

50 flats

 

Preprocessing:
Batch PreProcessing script to generate calibrated images
Typically would align by coronal details next but I was polar aligned from the previous night and called it good enough
ImageIntegration creating an average of each exposure bracket. No rejection or weighting.
LinearFit each stacked bracket to one of the RAW single exposures that made up the bracket.

 

Combining to HDR:
Loaded all 12 exposure stacks to the HDRComposite tool. Binarize threshold set to 0.4. Mask smoothness and growth set to max values. Set to generate 64-bit result.

 

NOTE: While I mainly write these steps for myself, keep in mind I iteratively create a new mask for nearly every processing step. The mask creation was 99% of the work while processing this image as the brightness ranges were

constantly being manipulated.

 

Processing:
DynamicBackgroundExtraction - 2 passes - Subtraction followed by Division
CloneStamp to remove a few dead pixels (probably a calibration error on my part)
ArcsinhStretch x3 followed by HistogramTransformation x8 using RangeMasks to manually perform iterative stretching
Deconvolution
HistogramTransformation x23 using RangeMasks to stretch into my HDR working image (note: controlling dynamic range as I stretched produced favorable results to stretching and then compressing. this was the most difficult and time consuming part)
LocalHistogramEqualization to display large-scale coronal details
LocalHistogramEqualization to display inner coronal details
GeneralizedHyperbolicStretch x2 to balance contrast
HistogramTransformation to balance background
MultiscaleLinearTransform to sharpen inner corona slightly
UnsharpMask to sharpen outer corona
UnsharpMask to sharpen inner corona
NoiseXTerminator on low signal outer regions
CurvesTransformation for color balance and saturation
SCNRGreen (while the corona did seem to have a natural green tint, it wasn't apparent naked eye and I made the choice to neutralize here)
LocalHistogramEqualization for slightly more contrast
BlurXTerminator only on stars to correct optic flaws
PixelMath to blend earthshine moon and prominences in from the unprocessed state of the image
LocalHistogramEqualization and CurvesTransformation to reveal moon details
IntegerResample to downsample 2x


  • PrestonE, Mert, tjay and 17 others like this

#2 alvarete

alvarete

    Viking 1

  • *****
  • Posts: 578
  • Joined: 14 Oct 2010

Posted 09 May 2024 - 03:35 PM

Fantastic image Kballzz!!,
A lot of work indeed. Thanks for sharing It with us.
  • KBALLZZ likes this

#3 Barlowbill

Barlowbill

    Vanguard

  • *****
  • Posts: 2,316
  • Joined: 05 Apr 2018
  • Loc: Tulsa, Oklahoma

Posted 09 May 2024 - 03:55 PM

Not exactly what I saw with 15X binoculars.  Duh!

Beautiful.


  • KBALLZZ likes this

#4 KBALLZZ

KBALLZZ

    Vostok 1

  • *****
  • topic starter
  • Posts: 161
  • Joined: 28 Dec 2015

Posted 09 May 2024 - 04:27 PM

Not exactly what I saw with 15X binoculars.  Duh!

Beautiful.

I'll take another look through binos vs having this image any day!


  • dan_hm likes this

#5 KMH

KMH

    Viking 1

  • *****
  • Posts: 585
  • Joined: 25 Apr 2014

Posted 10 May 2024 - 10:47 AM

Wow - that's amazing (and fascinating) detail you pulled out!  I think it's a terrific accompaniment to more "natural" looking images.

 

Kevin


  • KBALLZZ likes this



Reply to this topic



  

CNers have asked about a donation box for Cloudy Nights over the years, so here you go. Donation is not required by any means, so please enjoy your stay.


Recent Topics





Also tagged with one or more of these keywords: Astrophotography



Cloudy Nights LLC
Cloudy Nights Sponsor: Astronomics