Jump to content

Stargazers Lounge Uses Cookies

Like most websites, SGL uses cookies in order to deliver a secure, personalised service, to provide social media functions and to analyse our traffic. Continued use of SGL indicates your acceptance of our cookie policy.

stargazine_ep28_banner.thumb.jpg.b94278254f44dd38f3f7ee896fe45525.jpg

gnomus

Eastern Veil - NB Tricolour

Recommended Posts

We were quite pleased with our snap of the Bat Nebula https://stargazerslounge.com/topic/280222-bat-nebula-eastern-veil-bicolour/ until, that is, we saw this masterpiece from Bill Snyder http://billsnyderastrophotography.com/wp-content/uploads/2013/11/Eastern-Veil-CFHT-Ha-OIII-SII-PS1-V4-CR.jpg

Mr Snyder had used all three NB filters, but it was not at all clear to us how he achieved the final result.  We captured a couple of SII frames and tried doing multiple different combinations and blends but got nowhere near.  So eventually @MrsGnomus  e-mailed Bill.  He got back to her fairly quickly and said that he started off with a reasonably conventional SHO (Hubble) mix.  He then started by following Bob Franke's method -  http://www.bf-astro.com/hubbleP.htm 

I got the SII - last night with a ludicrously bright 'supermoon' looking on.  It was noticeable just how much brighter our 'black' level was with the moon around even with the 3nm Astrodon filter.  Also the Veil is really getting a bit too low in the sky I think.  All told we got around 3 hours of SII last night to go with the 5 hours of Ha and 3 hours 40 mins of OIII.  I did a SHO combination - followed by the Franke method and then I got decidedly trigger-happy with the Selective Colour tool in PS.  I don't think I would be able to reproduce what I did.  I didn't get anywhere near the Snyder image, but the result was 'interesting'.  Our bicolour shot is better.  Nevertheless, I might try to get some better SII next year when conditions are more favourable.  

The main lesson we learned was not to try imaging during a near full moon even with 3nm filters.  (We simultaneously tried getting some 3nm OIII through our widefield rig - the individual subs looked OK but once processed, it was clear that there was a massive gradient running across the frame which DBE only partially eliminated.)

SHO_V9.jpg

Comments and criticism welcomed as always - this is certainly more of a work-in-progress than a finished effort ....

  • Like 9

Share this post


Link to post
Share on other sites

To be honest I have a bicolour version of this, and then recently I finally acquired some Sii to go with it.  When I put it together I did not like the result as much as the bicolour version, so I scrapped it. 

I think in your case too I prefer the bicolour version, somehow the Sii seems to make it less striking in both our images. 

Carole 

 

 

  • Like 1

Share this post


Link to post
Share on other sites

Hi Steve

So far I am with Carole the bicolour version was top drawer, SII has killed some of that lovely smoothness and detail you managed.  Maybe just a case of waiting for better SII.

Have you tried blending in PI?  I would start with -   R=s*.76+h*.24, G=h*.85+s*.15, B=Ox1.0 - Then SCNR (adjust SCNR to taste)

See what that looks like - I hope to have a go at part of the Veil my self shortly - no evidence the above will work, it just does when i try on most NB targets (can always tweak ratios a little if desired).  Unlike any PS method PI seems to blend it 'better' (that's today's technical reference covered :) )  

Paddy

 

 

Share this post


Link to post
Share on other sites

I will try to 'Blend it like Gilliland'.  Let you know how I get on.

Share this post


Link to post
Share on other sites

Interesting point - I have all three sets of NB data ready to process in PixInsight but my previous efforts with the Veil (with Photoshop) showed a similar dilemma.  The SII just didn't improve it.  I have lots of data to process and an enormous amount to learn as I get to grips with PI !!

Share this post


Link to post
Share on other sites

If you already have the 3nm HII filter, then maybe give the [NII] a go as well. On the occasions I've tried I've seen more [NII] than [SII]. In fact, although I'm not sure I have the sub, when I was looking at the Eastern Veil last I tried a [NII] image and saw quite a bit of signal. Unfortunately the sky clouded over before I could do a proper run and I never got back to it as my house was getting in the way.

Share this post


Link to post
Share on other sites

Create an account or sign in to comment

You need to be a member in order to leave a comment

Create an account

Sign up for a new account in our community. It's easy!

Register a new account

Sign in

Already have an account? Sign in here.

Sign In Now

  • Recently Browsing   0 members

    No registered users viewing this page.

  • Similar Content

    • By MarsG76
      Hello All,
      I'm going through some of my subs which I captured earlier this year, but did not have a chance to process. This is my "War and Peace" nebula RGB subs processed which I captured on 22 June 2020, after the nights of imaging this nebula in Narrowband.
      Imaged at f6.3, 1280mm focal length, through my 8" SCT, cooled and modded Canon 40D for about 4 hours exposure time.
       
      CS,
      MG
       

    • By Spacecake2
      Today at 3am (Australia) I woke up and I tried to observe the Orion nebula. It was pretty hard to image it since I don't have a camera adapter and a had 4 second exposures. But after 20 tries I finally got non-wobbly image. The camera could see more than my own eyes! 
      (I live in bortle 7) ☹️

    • By Stargazer33
      Taken on the night of 12 September. 
      NGC6826 - The Blinking Nebula.
      This on Wiki:
      NGC6826 is a planetary nebula located in the constellation Cygnus. It is commonly referred to as the "blinking planetary", although many other nebulae exhibit such "blinking". When viewed through a small telescope, the brightness of the central star overwhelms the eye when viewed directly, obscuring the surrounding nebula. However, it can be viewed well using averted vision, which causes it to "blink" in and out of view as the observer's eye wanders. A distinctive feature of this nebula are the two bright patches on either side, which are known as Fast Low-Ionization Emission Regions, or FLIERS. They appear to be relatively young, moving outwards at supersonic speeds.
      Right ascension: 19 h 44 m 48.2 s
      Declination: +50° 31′ 30.3″
      Distance: ~2000 ly
      Apparent magnitude (V): 8.8
      Apparent dimensions (V): 27″ × 24″
      Constellation: Cygnus
      Radius: 0.22 x 0.20 ly
      Designations: HD 186924, SAO 31951, Caldwell 15
       
      Equipment: 
      Imaging: C9.25; CGEM (diy hypertuned); ASI385MC; Baader neodymium filter; Astro Photography Tool
      Guiding: Travelscope 70; SSAG; PHD2
      Processing: DSS; Photoshop CS4 Extended 
      99 x 20" lights, of which 63 were stacked; 50 x darks; 50x bias; 50 x flats

      Looks like I'm going to have to have another go at my collimation. Very happy with this even so, as it's the first serious imaging I've done for sooo long! A lot more data is required to bring out the detail in the nebula. 
      Comments/suggestions welcome.
    • By stevewanstall
      Messier 57 is is just coming into a position for a decent look around 11 30 pm. IT is a colourful object and I thought it would give me a good target with which to practice my colour developing in PS/Lightroom. I have read so much about how to produce a LRGB image from the four stacked/calibrated luminance, red, blue and green images,  a lot seems contradicatory and some, when followed, gave me colour yes, but not as we know it. I am sure a fair chunk must be put down to me. Anyway, I now have a work flow which gives me colour, sometimes resembling what other people have obtained. Progess of sorts.
      This images is based on 114s subs at gain 139, offset 21.
      L 39, R 20, G 20, B 19
      Calibrated  and stacked in DSS (flats, dark flats and darks)
      Messier 57 Ring Nebula in Lyra
       

      NASA: M57, or the Ring Nebula, is a planetary nebula, the glowing remains of a sun-like star. The tiny white dot in the centre of the nebula is the star’s hot core, called a white dwarf. M57 is about 2,000 light-years away in the constellation Lyra, and is best observed during August. Discovered by the French astronomer Antoine Darquier de Pellepoix in 1779, the Ring Nebula has an apparent magnitude of 8.8 and can be spotted with moderately sized telescopes.
      Equipment: Celestron 9.25 XLT at F10,  Skywatcher EQ6 Pro GEM, ZWO 1600MM Pro, ZWO EFW with ZWO LRGB filters, QHY5IIC guide camera on Skywatcher 9 x 50 finderscope, Celestron Focus Motor
      Software: Ascom 6, Eqmod, Cartes du Ciel, AstroPhotography Tool, PHD2
       
×
×
  • Create New...

Important Information

By using this site, you agree to our Terms of Use.