· Get a Cloudy Nights T-Shirt · Submit a Review / Article Click here if you are having trouble logging into the forums Privacy Policy | Please read our Terms of Service | Signup and Troubleshooting FAQ | Problems? PM a Red or a Green Gu… uh, User You are not logged in. [Login] Entrance · Main Index · Search · New user · Who's Online FAQ · Calendar Astrophotography and Sketching >> DSLR & Digital Camera Astro Imaging & Processing Previous   Index   Next   Threaded   Pages: 1 bluedandelion Carpal Tunnel Reged: 08/17/07 Loc: Hazy Hollow, Western WA M57 - Pixinsight reprocess       #5503347 - 11/04/12 01:50 AM Edit   Reply   Quote Quick Reply   M57, the Ring Nebula in Lyra. Captured in 2009 with a C9.25 at f/10 and a modified Canon 350D from a light polluted location. Total exposure was 45 minutes at ISO800. No filters were used. This is a center crop. Larger view on Flickr Ajay Post Extras:       mmalik Carpal Tunnel Reged: 01/13/12 Loc: USA Re: M57 - Pixinsight reprocess [Re: bluedandelion]       #5503390 - 11/04/12 04:07 AM Edit   Reply   Quote Quick Reply   Very nice looking Ring Nebula. If not too much to ask, would you be able to describe PixInsight processing in detail for learning/documentation sake? Post Extras:       srosenfraz Carpal Tunnel Reged: 03/06/11 Loc: United States Re: M57 - Pixinsight reprocess [Re: mmalik]       #5503764 - 11/04/12 11:22 AM Edit   Reply   Quote Quick Reply   That's an excellent Ring, Ajay. You have some great detail within the ring - nice job. Post Extras:       bluedandelion Carpal Tunnel Reged: 08/17/07 Loc: Hazy Hollow, Western WA Re: M57 - Pixinsight reprocess [Re: mmalik]       #5503771 - 11/04/12 11:28 AM Edit   Reply   Quote Quick Reply   Thank you Mike. There is actually more signal but I dare not stretch any more due to severe gradients due to light pollution. Here's my workflow: 1. Preprocess (i.e. Apply Flats, Flat Darks & Darks and Debayer) with Nebulosity 3. Everything else is done in PI 2. Register, Combine and Trim edges 3. Dynamic Background Subtraction 4. Color calibration 5. Noise reduction on unstretched image via Atrous Wavelets and Greycstoration Steps 2-5 are on the unstretched image. You can see what you are doing by using the Screen Transfer function. Noise is kept low because it is not stretched. 6. Stretch image via Histogram transfer 7. Improve dynamic range via HDR wavelets 8. Local Contrast Enhancement 9. Improve saturation via curves 10. A little Unsharp mask In some of these steps a Starmask or Luminance mask (or their inverse) was used. All these names make it sound daunting, but see Harry's tutorials for quick start recipes on most of these major steps. Ajay Edited by bluedandelion (11/05/12 10:52 AM) Post Extras:       petemumbower Pooh-Bah Reged: 07/12/09 Loc: West Michigan Re: M57 - Pixinsight reprocess [Re: bluedandelion]       #5504783 - 11/04/12 11:37 PM Edit   Reply   Quote Quick Reply   Great image Ajay, you have your C9.25 singing. Post Extras:       bluedandelion Carpal Tunnel Reged: 08/17/07 Loc: Hazy Hollow, Western WA Re: M57 - Pixinsight reprocess [Re: petemumbower]       #5505234 - 11/05/12 10:51 AM Edit   Reply   Quote Quick Reply   Thank you Scott and Pete. Ajay Post Extras:       Pages: 1 Previous   Index   Next   Threaded   Extra information 14 registered and 33 anonymous users are browsing this forum. 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