Deep-Sky Video Astronomy (eBook)

Deep-Sky Video Astronomy is a concise guide to using modern video cameras for deep-sky viewing and imaging with the kinds of modest telescopes available commercially to amateur astronomers. It is not a beginner's book, but it does include an introduction and brief history of the technology, camera types, etc. More importantly, the authors examine the pros and cons of this unrefrigerated yet highly efficient technology, which is already beginning to compete with expensive astronomical cooled-chip CCD cameras in quality and ease of use. The book also includes a thorough examination of the variety of accessories that are available and can be used to achieve a particular result. Examples of accessories are focal reducers, Barlow lenses, and optical filters. However, much of the book's focus is on the practical side of creating beautiful and detailed astronomical portraits using image-stacking software, picture enhancement tools such as Photoshop, and in creating color images using only a very sensitive black-and-white camera. Practical step-by-step examples, supported by tried and trusted tips, show how it is possible to achieve the best possible celestial deep-sky video portrait! There is also information on how this technology is being used for comet hunting, supernova patrols, lunar and Minor Planet occultations, astrometry, and meteoroid observations.

About the Authors 6
Contents 8
Introduction Deep-Sky Video Astronomy 11
Using Video for Astronomy 15
1.1 The Image Sensor 16
1.2 Efficiency in Astrophotography 18
1.3 Progressive Scan 18
1.4 Interlaced TV Images 18
1.5 Video Resolution 21
1.6 Low Light Performance 22
1.7 Hot Pixels 24
1.8 Color Versus Black and White 24
1.9 CCD Sizes and Image Scale 26
Cameras 30
2.1 Image Accumulation Cameras 30
2.2 Cameras Modified for Astronomy 33
2.3 Basic Camera Features 33
2.4 Camera Control 36
2.5 Shutter Speed 36
2.6 Signal Gain Control 37
2.7 Gamma Settings 38
2.8 Accumulation Mode 39
2.9 Video Cables and Connections 41
Video Capture 44
3.1 Digitizing Video 44
3.2 Software Capture Tools 45
3.3 Aspect Ratio 46
3.4 Capture Resolution 48
3.5 Image Quality 50
3.6 RGB Color Spaces 50
3.7 Recording Directly to DVD 51
3.8 Bright Object Smearing in Videotape Recordings 52
3.9 8-Bit Grayscale Images 53
3.10 Understanding Capture Rates 54
3.11 Storage Mediums 56
3.12 File Sizes 57
At the Telescope 59
4.1 Focal Reducers 59
4.2 Barlow Lens 60
4.3 Eyepiece Projection 62
4.4 Filters 63
4.5 Filter Selectors 63
4.6 Real-Time Video Observations 66
4.7 Creating a Video Portrait 67
4.8 Dark Frames 67
4.9 Flat Fields 68
4.10 Avoiding Dust Motes 71
4.11 Image Scale and Resolution 72
4.12 A Basic Plan for Your Imaging Session 73
4.13 Guiding and Tracking Corrections 78
4.14 How Many Images Should be Captured? 79
4.15 Framing Multiple Fields to Capture Large Objects 81
Initial Processing 83
5.1 Software for Initial Processing of Video Files 83
5.2 Stacking with Registax Direct from an AVI File 85
5.3 Manually Stacking Images 90
Final Processing 94
6.1 Calibrating Your Computer Monitor 95
6.2 Extracting the Detail 96
6.3 Vignette/Gradient Removal 101
6.4 Unsharp Masking 106
6.5 Making Color from Black 6 and White Images 114
6.6 Color Balance 118
6.7 Adding a Luminance Channel to RGB 123
6.8 Making a Simulated Green Channel 124
6.9 Adjusting Color Shift in Single CCD Color Camera Images 128
6.10 Removing Artifacts 128
6.11 Blending MultiField Images 137
6.12 Printed Video Images 141
6.13 Publishing Images to a Website 143
Other Video Applications 144
7.1 Lunar and Minor Planet Occultations 143
7.2 Astrometry 146
7.3 Supernova Searching 147
7.4 Meteor Observations 148
7.5 Video as a Guiding Tool 148
7.6 Manual Guiding 151
7.7 Automatic Guiding 152
7.8 Video Finderscope 153
7.9 Video Polar Alignment 155
7.10 Collimating with Video 155
7.11 Detecting Faint Planetary Moons 156
7.12 Near Infrared: Imaging the Unseen 157
The Gallery 160
8.1 Suburban Light-Polluted Skies 160
8.2 Dark Country Skies 171
Glossary 184
For Reference and Further Reading 189
Internet Sites of Interest 189
Index 191