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

Corona in Eclipse photos?

5 replies to this topic

#1 MichaelJB

MichaelJB

    Vostok 1

  • -----
  • topic starter
  • Posts: 174
  • Joined: 01 Jan 2022
  • Loc: Lower Nazareth, PA

Posted 06 February 2024 - 10:28 AM

How are those pictures of the corona 'created' in those typical Total Solar Eclipse pics that we commonly see?

 

Does the Corona appear through white light filters? (Herschel Wedge?)

 

 Eclipse.jpeg



#2 CreatorsHand

CreatorsHand

    Ranger 4

  • *****
  • Posts: 387
  • Joined: 21 Jun 2022
  • Loc: Marquette, Michigan

Posted 06 February 2024 - 12:46 PM

The filter has to be removed to be able to photograph the corona, and to capture the Diamond ring effect and Bailey's Beads, which happen within 15 to 20 seconds either side of totality. You then take a series of images, ranging from something like 1/2000 second to 2 to 4 seconds (depending on your equipment and f/stop or focal ratio) and create a high dynamic range image from the individual images. In 2017 I captured 7 bracketed images 2 stops apart centered around 1/60 second or 1/30 second, and then used HDR software to combine them. I will be doing something similar this year, but plan to use Eclipse Orchestrator on at least one camera to allow me to capture images closer together in exposure.

 

Paul

 

2017 Solar Eclipse-5331G.jpg


  • R Botero, MichaelJB and Wolfwatcher like this

#3 MichaelJB

MichaelJB

    Vostok 1

  • -----
  • topic starter
  • Posts: 174
  • Joined: 01 Jan 2022
  • Loc: Lower Nazareth, PA

Posted 06 February 2024 - 01:47 PM

So this is done with no filter, natural light... no white light?

 

 

The filter has to be removed to be able to photograph the corona, and to capture the Diamond ring effect and Bailey's Beads, which happen within 15 to 20 seconds either side of totality. You then take a series of images, ranging from something like 1/2000 second to 2 to 4 seconds (depending on your equipment and f/stop or focal ratio) and create a high dynamic range image from the individual images. In 2017 I captured 7 bracketed images 2 stops apart centered around 1/60 second or 1/30 second, and then used HDR software to combine them. I will be doing something similar this year, but plan to use Eclipse Orchestrator on at least one camera to allow me to capture images closer together in exposure.

 

Paul

 

attachicon.gif 2017 Solar Eclipse-5331G.jpg


  • CreatorsHand likes this

#4 CreatorsHand

CreatorsHand

    Ranger 4

  • *****
  • Posts: 387
  • Joined: 21 Jun 2022
  • Loc: Marquette, Michigan

Posted 06 February 2024 - 01:59 PM

So this is done with no filter, natural light... no white light?

Yes, that is the whole point of going to the effort to be within the path of totality; that is the only time that you can see the Sun's corona, and the only time that you can look at the Sun without solar glasses. I should note that while you can photograph the Sun 30 seconds or less either side of totality, it is not safe to look at the Sun without solar glasses until after the start of totality. During totality, the Moon blocks the sunlight, allowing us to see and photograph the corona. With a filter still in place during totality, the corona is dim enough that you will get nothing in your images; just ask those that have forgotten to remove their filter. During an annular solar eclipse, such as the one last October, where there is no totality, or outside the path of totality, this does not apply and you cannot remove the filter or look without solar glasses. The closer you are to the center of the path of totality during a total solar eclipse, the longer totality will last.

 

Paul


  • R Botero, Celerondon and MichaelJB like this

#5 Cajundaddy

Cajundaddy

    Vanguard

  • *****
  • Posts: 2,264
  • Joined: 27 Dec 2016
  • Loc: Southern Idaho

Posted 06 February 2024 - 04:13 PM

Yes.  The photo in the OP is similar to my best single exposure from 2017.  The corona is roughly the brightness of a crescent moon so you can use the moon as a model to test exposures with your camera/lens setup.  Always best to shoot bracketed exposures for the best single image or to stack and create an HDR composite revealing the outer corona tendrils as well. 

Cheers!


  • lezrob likes this

#6 Alex McConahay

Alex McConahay

    Hubble

  • *****
  • Posts: 13,331
  • Joined: 11 Aug 2008
  • Loc: Moreno Valley, CA

Posted 19 March 2024 - 09:07 PM

Just to be more specific, all images taken during totality are taken without solar filters. 

 

And your question about Herschel Wedge?----No, you would not use one then. A Herschel Wedge is not too useful during a total eclipse expedition. You could certainly use it during the partial phases, but then in the very few seconds between partial and total, you would need to remove it and replace it with another diagonal and eyepiece, perhaps refocus---------and that is certainly something you do not want to be doing anywhere near totality. 

 

To get back to how the beautiful image in post #2 is made----it starts with a series of exposures taken at various exposure settings. They are processed to emphasize one area (brightness level) or another of the image. Then they are blended together. In the center, you use one of the shortest exposures, because it is brightest. Then overlay the next brightest exposure level, and so forth until you are overlaying the farthest out. In that one, the center is completely blown out, so you have to hide its center. And, of course, you do the same for every other level until you have blended them all together.  It is not much more complicated than that (in theory) but it takes patience and skill.  But, yes, the picture in #2 started as a set of simple white light exposures taken at different exposure levels.

 

Alex 


  • CreatorsHand 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






Cloudy Nights LLC
Cloudy Nights Sponsor: Astronomics