Transcript Small Refractor CCD Imaging - Stargazing Network Main Page

Small Refractor CCD Imaging
David Haworth
http://www.stargazing.net/david/
Agenda

Equipment

Imaging session

Image processing

Advantages

Disadvantages
© 1999 David Haworth
Small Refractor CCD Imaging
Page: 2
Equipment
CCD Cookbook CB245 camera
 Orion ShortTube™ 80mm refractor

– 400mm Focal length
– 13 x 10 arc second/photosite

Piggy back on Celestron CG-11 SchmidtCassegrain telescope
© 1999 David Haworth
Small Refractor CCD Imaging
Page: 3
CCD Cookbook CB245 Camera
Interface to PC
Water Cooling
Spectra Astro Systems Shutter
Camera Head
IR Filter to Reduce Focusing Problem
CCD IC
Spectra Astro Systems Shutter
Santa Barbara
Instrument Group
IR Filter in
T-mount extension tube
Monitoring CCD Temperature
CCD IC
Thermistor
mounted
on CCD IC
Typical  from water = 62°F
Spectra Astro Systems Shutter
Shutter for Taking
Dark Frames
CCD Cookbook CB245 Camera
T-ring with
IR Filter
Spectra Astro
Systems Shutter
CCD Cookbook CB245 Camera Mounted
on Orion ShortTube Refractor
CCD Camera
T-ring Camera Support
T-ring Camera Support
Orion Piggy Back on Celestron CG-11
Imaging Session

On the driveway observing

Reducing setup & tear down time

Typical imaging session

Dark frames

Multiple images
© 1999 David Haworth
Small Refractor CCD Imaging
Page: 12
Telescope is Setup on a Dolly
Telescope is Lifted on Blocks
Astro Trailer
Computer Ready to Control the Camera
Ready for Night Time Imaging
Roll a way Table
With Dew Cover
Astro Trailer
CCD Cooling
Water
Cooling the CCD Camera
Water Thermometer
Open System
Cooling Water
Water Pump (12VDC)
Quick Disconnect Water Hoses
Image Processing

Richard Berry's software
– Multi245: calibration & stacking
– CB245: Kunihiko Okano's Digital Development
functions
© 1999 David Haworth
Small Refractor CCD Imaging
Page: 20
Multi245: Stacking Multiple Images
One 15 Seconds Image
31 - 15 Seconds Images
CB245: Kunihiko Okano's Digital Development
M13
Without
With
Image Processing

Software Bisque CCDSoft CCD Astronomy
software
– Brightness & contrast adjustment, rotating
image, resampling the image to correct aspect
ratio and saving the image as a JPEG file

JASC Paint Shop Pro software
– Image cropping & creating mosaics
© 1999 David Haworth
Small Refractor CCD Imaging
Page: 23
CCDSoft - Aspect Ratio Resampling
M42
242 x 252
187 x 252
Paint Shop Pro - Crop Star Blooming
M37
Uncropped
Cropped
Paint Shop Pro - M31, M32 & M110 Mosaic
M32
M110
Advantages

Large field of view
– 55 x 41 arc min. vs. CG-11 12 x 9 arc min.
– Large object imaging

M8, M33, M42, M78, etc.
Finding objects is easier
 Reduced polar alignment errors effects
 Reduced tracking errors effects

© 1999 David Haworth
Small Refractor CCD Imaging
Page: 27
Large Field of View 41 x 55 arc min.
M33
M78
Large Field of View 41 x 55 arc min.
M81 & M82
Horsehead B33
M11 & Dark Nebulas
M8
M17
Disadvantages

Small objects do not image very well
– M57, M72, M75, M76, etc.

Small 80mm aperture
© 1999 David Haworth
Small Refractor CCD Imaging
Page: 32
Small Objects do Not Image Very Well
M57
M76
Small 80 mm Aperture NGC7331
Zoom in NGC7331
14.7
?
15.2
16.9
14.5
10.3
STScI Digitized Sky Survey (DSS) 48-inch NGC7331
?
Other Images

70 Messier objects
– ITS ‘99 CD-ROM
– http://www.stargazing.net/david
© 1999 David Haworth
Small Refractor CCD Imaging
Page: 37