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

Success in Framing the Blue Horsehead & Rho Ophiuchi Nebulas

dslr dso astrophotography
  • Please log in to reply
10 replies to this topic

#1 BQ Octantis

BQ Octantis

    Vanguard

  • *****
  • topic starter
  • Posts: 2,367
  • Joined: 29 Apr 2017
  • Loc: Red Centre, Oz

Posted 23 May 2020 - 05:54 AM

I was considering going after the Blue Horsehead nebula with the 200mm last night, but I opted to improve my results through the 50mm. At least this time I had some idea of what was in the scene. My flat was also causing me trouble with reducing the light pollution, so I used one of the diffusers from my son's lighting set on the LCD TV set to ~40% gray output. I couldn't be happier with the result:

 

(Click for full size.)

1440x900.jpg

Capture details / 1800×1200 (.jpg, 48%) / Astrobin (.jpg, 100%)

 

Cheers,

 

BQ


Edited by BQ Octantis, 23 May 2020 - 09:14 PM.

  • Diego, Starman27, fishonkevin and 8 others like this

#2 BQ Octantis

BQ Octantis

    Vanguard

  • *****
  • topic starter
  • Posts: 2,367
  • Joined: 29 Apr 2017
  • Loc: Red Centre, Oz

Posted 23 May 2020 - 11:00 AM

Whoops…I completely forgot to turn up the reds and blues! Apologies…I'll try to update the larger sizes tomorrow.

 

(Click for full size.)

1440x900a.jpg

 

BQ


  • Joe G, shark-bait, Foc and 3 others like this

#3 Diego

Diego

    Viking 1

  • -----
  • Posts: 534
  • Joined: 29 Jul 2003
  • Loc: Cordoba, Argentina South America

Posted 23 May 2020 - 11:56 AM

BQ I'm becoming a big fan of your pictures!! Simply amazing!

I've noticed for most of your pictures you take many exposures of 30 to 60 seconds and was curious why you don't take longer exposures of say 2 to 3 minutes.

Any particular reason for multiple shorter exposures?

Thanks!

#4 sunnyday

sunnyday

    Fly Me to the Moon

  • *****
  • Posts: 6,568
  • Joined: 23 Sep 2019
  • Loc: Ottawa,Canada

Posted 23 May 2020 - 11:56 AM

BQ I'm becoming a big fan of your pictures!! Simply amazing!

I've noticed for most of your pictures you take many exposures of 30 to 60 seconds and was curious why you don't take longer exposures of say 2 to 3 minutes.

Any particular reason for multiple shorter exposures?

Thanks!

+1



#5 BQ Octantis

BQ Octantis

    Vanguard

  • *****
  • topic starter
  • Posts: 2,367
  • Joined: 29 Apr 2017
  • Loc: Red Centre, Oz

Posted 23 May 2020 - 07:27 PM

Thanks to all for the feedback and likes!

 

I use 30 second exposures because this is close to the star streak limit of my mount's unguided performance at 200mm. And 30 seconds is plenty at f/2.8 (the equivalent at f/4 is 60 seconds). The reason you often see much longer exposures is because better refractors (apos) tend to be at f/6-f/7, which require 5-6 times more integration time than an f/2.8.

 

As promised, I uploaded the updates—just follow the links to the larger images in the first post.

 

BQ


Edited by BQ Octantis, 23 May 2020 - 09:02 PM.

  • sunnyday likes this

#6 Diego

Diego

    Viking 1

  • -----
  • Posts: 534
  • Joined: 29 Jul 2003
  • Loc: Cordoba, Argentina South America

Posted 23 May 2020 - 09:11 PM

Thanks for explanation!!! Not to mention that the updated pictures are simply stunning!!! Great work!

#7 BQ Octantis

BQ Octantis

    Vanguard

  • *****
  • topic starter
  • Posts: 2,367
  • Joined: 29 Apr 2017
  • Loc: Red Centre, Oz

Posted 23 May 2020 - 09:13 PM

Thanks for explanation!!! Not to mention that the updated pictures are simply stunning!!! Great work!

No worries, mate!

 

Curiously, the 1800x1200 .png is not accurately portraying what I created. So I uploaded a .jpg with a color profile in its place.

 

BQ



#8 travishv

travishv

    Lift Off

  • -----
  • Posts: 21
  • Joined: 30 Jan 2020
  • Loc: Hamilton, Ontario

Posted 24 May 2020 - 12:09 AM

Looks amazing. Lots of detail and colour!



#9 shark-bait

shark-bait

    Viking 1

  • -----
  • Posts: 739
  • Joined: 01 Jun 2009
  • Loc: New Port Richey, FL USA

Posted 24 May 2020 - 06:54 AM

I really like what you have done here with modest equipment BQ. I assume you used no filter and only a single flat frame? I will definitely give that a try!


Also, do you combine two separate sets of images to increase the dynamic range? I have only shot at a single exposure setting and am curious.

Thank you and well done.

#10 BQ Octantis

BQ Octantis

    Vanguard

  • *****
  • topic starter
  • Posts: 2,367
  • Joined: 29 Apr 2017
  • Loc: Red Centre, Oz

Posted 24 May 2020 - 09:33 AM

Hi Shark Bait,

 

You are correct: no filter and just one ISO100 AWB aperture priority flat. RawTherapee just blurs the flat, so no more than that.

 

As to combining, I used a starless f/2.8 layer to enhance the f/4 image (specifically, as a screen layer with the opacity set to whatever gives me the minimum entropy I can detect with the eyeball with a normal layer). f/2.8 saves so much time, I'd use all f/2.8 if it weren't for its softness and bad stars!

 

Cheers,

 

BQ


Edited by BQ Octantis, 24 May 2020 - 09:33 AM.


#11 LuigiL

LuigiL

    Lift Off

  • -----
  • Posts: 19
  • Joined: 03 May 2020

Posted 24 May 2020 - 10:13 AM

Beautiful image! And 60" is not too much so that's a nice work! :)




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: dslr, dso, astrophotography



Cloudy Nights LLC
Cloudy Nights Sponsor: Astronomics