Jump to content

SkySurveyBanner.jpg.21855908fce40597655603b6c9af720d.jpg

Comet C/2015 V2 Johnson


Recommended Posts

Image of comet C/2015 V2 Johnson currently in the constellation of Hercules, acquired on the night of Saturday 22 April 2017.  Taken with a Canon 450D attached to a Evostar ED80 Pro.  It's a composite image processed twice in DSS, firstly to register the stars and secondly to register the position of the comet.  Stretched and processed a little in PS.  

comet + stars 4 cropped.png

Link to comment
Share on other sites

10 hours ago, happy-kat said:

Getting a hint of a tail. Nice. How long were your exposures?

It was a bit stubbier than I expected somehow.

Exposures: 16 x 300s at ISO 400, dithered, no darks, bias frames and flats. 

Link to comment
Share on other sites

21 hours ago, tooth_dr said:

Super image. Composite sounds tricky to do 

"Composite" is a posh word for some processing I made up as I went along. :)

 I started out with two images from DSS. One registered and stacked on the stars (showing fuzzy comet) and the other registered and stacked on the comet (showing fuzzy stars).

In PS I stretched both images by the same amount so I could see some detail. I then placed the sharp star field image as a layer on top of the stacked comet image. I then used the  eraser tool to carefully remove the fuzzy comet in the top layer to reveal the sharp comet image underneath. I had to be careful not to remove the stars close to and even shining through the comet's tail.  I suppose it's a bit of a cheat really. 

I then stretched the flattened image a tad more, and neutralised the background sky a bit too.  

I've no idea whether there are better ways to do it. Suggestions welcome. 

It occured to me afterwards that it might be better to get some images guiding on the comet itself, then get some images guiding on the background star field, and finally combine the two. This might have given me a slightly sharper looking comet. 

Link to comment
Share on other sites

  • 2 weeks later...

Thanks for this Sub Dwarf. I've been wondering how to approach getting shots of Johnson. This is a really good start. I'd be interested to hear about other people's strategies too. I was wondering about going back a week later and reshooting the starfield but I guess that really would be cheating!

Link to comment
Share on other sites

Archived

This topic is now archived and is closed to further replies.

  • Recently Browsing   0 members

    • No registered users viewing this page.
×
×
  • Create New...

Important Information

We have placed cookies on your device to help make this website better. You can adjust your cookie settings, otherwise we'll assume you're okay to continue. By using this site, you agree to our Terms of Use.