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.

sgl_imaging_challenge_banner_dslr_mirrorlesss_winners.thumb.jpg.9deb4a8db27e7485a7bb99d98667c94e.jpg

Recommended Posts

Nice, clear and moon-free last night so I was looking forward to getting some colour subs for various targets, in particular this one!

To add to my existing Ha for IC 1805, I gathered some 4min & 2min (lower ISO) subs; the idea of these being to try and maintain star colour on the brighter stars.

I combined this colour data with the Ha and came up with the following. This nebula is almost entirely Ha it seems, and it's suprising how little colour data is needed when you have a decent Ha layer for it! (I say this because it works pretty well when only comined with a few of these colour subs) Still, it takes the total integration time over 13 hours which is by far my record!

All comments & suggestiong are, as always, very welcome. I'm rather tired today so not sure my eyes are working properly!

Ha: 66x600s ISO-800

Colour: 23x240s ISO-800

Extra star colour: 18x120s ISO-400

Camera: Canon 450D, modded

Scope: Skywatcher 150PDS

Mount: Vixen GP

Guiding: Orion mini finderguider + SPC900 webcam (unmodded)

gallery_5051_1080_178861.jpg

  • Like 2

Share this post


Link to post
Share on other sites

13 hours..... thats a long time! Bet youre desparate to move on now! :D

The only suggestion I can think of with this one is a little bit of contrast enhancement for the Ha layer, other than that - its great! Well worth the effort put in.

Share this post


Link to post
Share on other sites

lewis thats awesome it looks very deep in the middle there and the star color is great well done!

Share this post


Link to post
Share on other sites

I like this very much - keeping nice star colours when combining RGB with Ha can be challenging but I like the balance that you have achieved.

Share this post


Link to post
Share on other sites

Great image, Lewis!

Stars are perfect May be just a bit of local contrast enhancements.

Mark

Share this post


Link to post
Share on other sites

I very much like this too - The nebula's got some lovely detail, but I particularly like the star colour you've captured / retained... and also the apparent lack of noise - Well worth the effort of 13 hours, and an excellent DSLR image...

Share this post


Link to post
Share on other sites

Superb data in there :) Really lovely image :) Here's a tweek in PS - hope you don't mind and hope you like it :)

post-13131-0-06433000-1347460326_thumb.p

Share this post


Link to post
Share on other sites

Thanks all :D

No I don't mind at all Gina. Perhaps the image could indeed be pushed a bit further at this scale.

I will see what effect a hint of local contrast enhancement does for it too - thanks for the suggestion Rob and Mark!

Share this post


Link to post
Share on other sites

Ok, here's my tweaked version. Improvement? As suggested, I've used some contrast enhancement and pushed the levels a little more.

I've tried to keep the reds looking red; they usually turn a bit pink when bringing Ha into the luminance. To compensate, I add the Ha in lighten mode first, then apply more Ha luminance to the red channel than the others. Not sure I have fully achieved that or not...

There are blueish regions throughout the nebula that are just starting to show here, but mostly the Ha washes them out - maybe one day I'll get an OIII filter and try that! :)

gallery_5051_1080_1032543.jpg

Share this post


Link to post
Share on other sites

And here's a cropped region of interest. It almost stands up to this scale...

gallery_5051_1080_319450.jpg

Share this post


Link to post
Share on other sites

That's is indeed an improvident, Lewis!

To remove pink cast you can also use selective color in PS.

Another way to preserve color is to add initial layer above the luminosity layer and change the mode to Soft light.

You can then play with opacity.

Mark

Mark

Share this post


Link to post
Share on other sites

That's great. No other way to put it.

I say this a lot, I know, but I think there is green noise in there which PI's SCNR green would nail as would Hasta La VIsta Green, free from Rogelio's Deep Sky Colors.

Olly

Share this post


Link to post
Share on other sites

Your keen eye was quite correct as usual Olly! I tried out HLVG and it worked its magic. I also improved a few dodgy stars in the central cluster.

One of these days I'll get it right first time!

gallery_5051_1080_408933.jpg

Edited by Shibby

Share this post


Link to post
Share on other sites

An excellent rework - Until you posted the HLVG'd image I didn't notice the slight green cast at all... (Well spotted Olly!)

Share this post


Link to post
Share on other sites

Join the conversation

You can post now and register later. If you have an account, sign in now to post with your account.

Guest
Reply to this topic...

×   Pasted as rich text.   Paste as plain text instead

  Only 75 emoji are allowed.

×   Your link has been automatically embedded.   Display as a link instead

×   Your previous content has been restored.   Clear editor

×   You cannot paste images directly. Upload or insert images from URL.


  • Recently Browsing   0 members

    No registered users viewing this page.

  • Similar Content

    • By knobby
      Slowly dabbling with narrow band and the processing that is becoming more like art than science ūüôā
      I really am enjoying it though, Imaged this in my red zone back garden last night, it's 10 x  300 secs each of Ha Oiii and Sii ( no darks as they looked weird )
      Thanks for looking / feedback.
      DSS - Photoshop levels / curves - gradient xterminator - photoshop channel combine as per @swag72 tutorial - photoshop levels to balance colours to my taste - slight noise and star size reduction  (Noels tools)

    • By tooth_dr
      I scrapped all the Oiii and Sii data I previously took during a full moon (about 15 hours worth) and retook it all when the moon was a bit smaller at 76%.  Ha was taken during 98% and 67% moon.  All the lights were taken on the following nights: 12th, 19th and 20th September 2019.
      Integration times, all in 600s subs unbinned:
      Ha = 28.33 hours
      Oiii= = 5.67 hours
      Sii = 5.67 hours
       
      The Ha data is really nice, and unsurprisingly the Oiii and Sii is not as strong (or nice).
      I'm missing that (vital) step in my processing routine of getting the Sii and Oiii properly stretched to match the Ha, before combining.  I dont really know how to deal with the weaker data properly.  Any pointers would be appreciated.
      What I do currently:
      All the data is loaded into APP into separate channels/sessions.
      The data is stacked and registered against the best Ha sub
      This produces individual stacks of Ha, Sii and Oiii that are all registered
      Each channel is processed with DPP in APP and then saved as a 16bit TIFF
      Each is opened in PS
      Stars removed with AA and any remnants removed and tidied up
      I then open a blank RGB document in PS
      I paste Ha into Green, Sii into Red and Oiii into Blue
      Adjust the selective colour settings to get 'Hubble palette'
      Adjust levels, curves, saturation until looks ok
      All the Ha Sii Oiii data is then combined together in a single 'super' stack in APP using quality weighted algorithm to create a 'luminance'
      That luminance layer is adjusted using levels, curves, and NC tools such as local contrast enhancement and deep space noise reduction (using masks to apply as required)
      The luminance is pasted onto the above colour layer, and incrementally added using gaussian blur
      Cropped and saved.
       
       
      Here it is anyway   I haven't intended on any more exposure time for this one, but will consider it, if the expert opinion dictates otherwise!
       
      CS
      Adam
       


    • By Star101
      Taken 27 July 19. from my ROR Garden Shed.
      I did take the stars out using Starnet but prefered the stars in
      30 x 300s SII,Ha,OIII - 2.5Hrs
      TS65EQ with Atik EFW2 and ZWO AOG, Lodestar X2 guidcam.
      Mesu 200 mount
      ZWO 183mm pro at -20C 200 Gain.
      Processed in Pixinsight.
      Thanks for looking.

    • By StaceStar
      Hi still learning the ropes with my new Hypercam 183c pro
       
      i took this image of the heart nebula the other evening, and now I realise I want a scope with a shorter focal length haha.
       
      22x 240s stacked and calibrated in PI. Final touch up in PS 2018
      SW ED80 DS pro with Altair light wave 0.8 reducer. Heq5 pro, Altair astro hypercam 183c pro. Guided. 
       


√ó
×
  • Create New...

Important Information

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