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)

5. How color is created
Debayering the matrix….. greyscale data converted to RGB image

6. Processing after demosiacing
Irreversible process best done on a computer and not in the camera

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 ( 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