1 / 22

DSLR Astrophotograpy ….. My way

DSLR Astrophotograpy ….. My way. My camera. Why Canon?. Provides RAW files Not directly useable as an image “ Digital negatives”….unprocessed readout of pixels Well suited for dark subtracting and flat fielding…. not true of Nikon

prem
Download Presentation

DSLR Astrophotograpy ….. My way

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript

  1. DSLR Astrophotograpy….. My way

  2. My camera

  3. Why Canon? • Provides RAW files • Not directly useable as an image • “Digital negatives”….unprocessed readout of pixels • Well suited for dark subtracting and flat fielding…. not true of Nikon • Canon uses CMOS (complementary metal oxide semiconductor) sensor • Less sensitive than CCD, but cheaper to make • Generally consume less power than CCDs • Provide excellent color

  4. One shot color (Bayer Matrix) http://www.cambridgeincolour.com/tutorials/camera-sensors.htm

  5. How color is created Debayering the matrix…..greyscale data converted to RGB image http://www.cambridgeincolour.com/tutorials/camera-sensors.htm

  6. Processing after demosiacing Irreversible process best done on a computer and not in the camera http://www.cambridgeincolour.com/tutorials/raw-file-format.htm

  7. Other reasons to use Canon • Software readily available • Acquisition (Images Plus, Backyard EOS, Nebulosity, DigiCamControl • Processing (Images Plus, PixInsight, Nebulosity, Deep Sky Stacker • Gain from the experience of others • Yahoo Group Digital Astro • Yahoo Group DSLR Astro Image Processing • Cloudy Nights DSLR & Digital Camera Astro Imaging & Processing • Jerry Lodriguss CCD books are excellent and website • Books, adaptors, modifications, etc are widely available

  8. Why modify the canon sensor? Stock IR cut filter limits Ha response of sensor

  9. Modified camera is a must

  10. Downsides of modifying camera • Must use custom white balance • Auto mode will not work with custom white balance in older Canons… must use P or M mode • Canon Warranty is void and they will not service the camera • Cost is $200 - $300 (Hutech, Hap Griffin, Gary Honis)

  11. Comparing Canon Cameras

  12. APS-C sensor (advanced photo system)

  13. Lenses and telescopes that I use • 17-40mm f/4 Canon • 85mm f/1.8 Canon (Image scale 13.5 arcsec/pixel) • 200mm f/2.8 Canon (IS 5.4) • Borg 77ED refractor, f/5.5 (IS 2.5) • TAK FSQ 106 refractor, f/5 (IS 2) • TEC 140 refractor, f/7 (IS 1.1)

  14. Connecting to the telescope

  15. Image acquisition • Important to use a computer because it gives the best focus • Images Plus Camera Control • Many features….DSLR (Canon and Nikon), CCD, video • Autofocus control for motorized focusers; temperature compensation • $240, includes image processing software • Very good video tutorials • Backyard EOS • Only for Canon cameras • Manual focus aid plus framing aid, drift alignment, video, eclipse mode • Only $30

  16. Backyard EOS focusing

  17. Typical exposures • Usually stop down lenses a couple of stops • Always use ISO1600 (never go below ISO800) • Always collect RAW images (optional plus JPEG or TIFF) • Usually 3-4 minute unquided exposures • Total exposure time usually 1-2 hours (15-30 exposures) • Dark site is important

  18. Image processing • Images Plus • Dark subtraction • Debayering conversion to color FITS • Grading • File conversion to 16-bit TIFF • Could do everything in Images Plus

  19. Images plus

  20. Registar • Use for aligning and combining (usually) • Fool proof and very flexible

  21. CCDStack • Use for digital development (non linear stretch), creation of luminance image, deconfolution of luminance

  22. Photoshop for the rest of processing

More Related