1. Front Yard CCD Astrophotography
January 11, 2007

2. My Recommendations for starting
Learn!
Purchase/read “The New CCD Astronomy” by Ron Wodaski
Purchase/read “Photoshop for Astrophotographers” by Jerry Lodriguss
SBIG users group
Websites:
(Russell Croman)
(Robert Gendler)
(Jim Misti)
Club expert/mentor (John Boudreau)
Webcam and planets/moon

3. What can I do? Start: Photographs of the moon and planets Webcam
Registax
Good scope
Moderate tracking ability
Works from light polluted areas (bright objects)
Good results with minimal investment obtained from stacking hundreds of images

4. What can I do? Deep-sky objects from Andover
Light pollution effects photograph quality (increased sky background noise )
Long exposure times >5 hours/object
Practical implications of seeing conditions
Good to high level quality equipment produce better quality photos (expense/investment)
Produce good quality photographs
Digital Development Processing algorithms (DDP) and photo-processing “workflows” can correct many problems

5. Deep Sky CCD – Mount Selection
Spend 60% of money on Mount
Periodic error correction (PEC)
30 sec exposure less important
30 min exposure requires good PEC and tracking (auto guiding)
Telescope focal length significant factor
Accurate auto-guiding
Worm-gear design
Motor design

6. Deep Sky-Mount Suggestions
I use Astro-Physics 900 GTO
Mounts others have used
Losmandy (G11 and Titan)
Takahashi
Paramount
Mountain Instruments
Meade (RX400, LX200)
Celestron (CGE)

7. Learn characteristics of your mount-Auto-guiding
Balance
“Slight” east weighting
Appropriate selection of weights to center moment arms
Adjust worm gear / mesh
Software or mount firmware PEC correction

8. Deep Sky CCD – Telescope Focal Length (ref: “The New CCD Astronomy”)
Seeing
Aperture
Targets
Flexibility
Rarely
3-6”
Big targets
Good-add Barlow
A consideration
5-10”
More targets
Good if focal reducers available
Always matters
8-16”
Many more targets

9. Deep Sky – Telescope Selection
Better optical quality provides sharp correct color round stars
Recommend match telescope with CCD camera (ref:
Telescope Field of View
CCD chip size
CCD chip pixel size
Flat field needed
Adapter for telescope (field flattener)
Optical design with flat field (modified Petzval)
Astro-Physics sells adapter for SBIG cameras that fits in front of camera ( -CCD Telecompressor (CCDT67))

10. My Deep Sky Telescope Selection
Takahashi FSQ 106 N
APO fluorite refractor
Modified Petzval - 88mm circle flat field image
4” focuser
3600 camera angle adjuster
Aperture 106mm
Focal length 530mm
Compatible with large CCD chips currently on market

11. Modified Petzval Design

12. Deep Sky-CCD Camera Selection
Anti-Blooming Gate (ABG)
Easier to use
Less sensitive
Non-Anti-Blooming Gate (NABG)
More sensitive
Careful planning of exposure time needed (experience)
Minor blooming can be fixed
Software
Photo Processing takes more time

13. Camera Designs One-shot color camera Black and white with filter wheel
Filters located on chip – no filter wheel
Easy to use –good example is planets via webcam
Less flexible
Black and white with filter wheel
Flexible – can use many different types of filters
More complex to photo-process to color image
Better control over quality and composition of color image

14. Match Camera, Telescope and Mount
Telescope focal length (ref:
Ability of mount to track and guide effectively
Compensate for longer exposure times needed for ABG
NABG better if short exposure times are needed to match mount capability
Light pollution-NABG offers advantage

15. Auto-guiding options Separate CCD and scope for guiding
Camera with built-in guide chip (Santa Barbara Instrument Group, Inc (SBIG))
Don’t guide
Webcam
Short exposures (30 sec) and stack 50 – 200 images
Improve signal to noise

16. My Camera Selection SBIG ST-2000XM (ref: SBIG website)

17. My Camera Selection SBIG ST-2000XM (ref: SBIG website)

18. My Camera Selection SBIG ST-2000XM

19. My Camera Selection SBIG ST-2000XM

20. Photo Session-Focus Maxim DL Software
View of star size and number of small faint stars
Optimize for maximum intensity for star (signal)
Optimize for Full Width at Half Maximum (FWHM)

21. Focus Zen-Maxim DL Gross focus with imaging chip at 2 bin
Fine focus small selected area of CCD at full resolution 1bin
Set exposure time at >2 sec so that changes in seeing are not major factor
Watch temperature
FSQ in focus range is 35 microns
Temperature change >20F causes stars to bloat and loss in signal
Focus-aid: Plan to purchase Robo-Focus

22. Photo Session – Object Study object
Size (mosaic will need to be planned)
Color
Brightness
Globular cluster uniform
Galaxy Bright core faint outer region
Nebula have strong narrow band emissions
Filter selection
Luminance for white light detail (L)
Red, Blue, Green (RGB) for color
Halpha ( nm) narrow band filter for red nebula
Narrow band filter composites
Match filters to object and combine (LRGB, RRGB, HalphaGB, LHalphaRGB)

23. Photo Session – Frame and Lock
Locate object
Roughly frame object on image chip
Find suitable guide-star (>25000 ADU for filter transmitting lowest signal – Halpha)
Finalize object framing
Lock on guide star
Auto-guide

24. Photo Session-CCD Camera Correction Frames
Dark Frames. Correct for dark current that increases as a function of time and temperature (Thermal signal)
Bias Frames. Bias that occurs when pixel is read by camera (Zero light exposure)

25. Photo Session – Flat Field Correction for Optics

26. Taking Flat Field Frames