Astrophotography

Astrophotography

by Thierry Legault
Released June 2014
Publisher(s): Rocky Nook
ISBN: 9781492015611

Read it now on the O’Reilly learning platform with a 10-day free trial.

O’Reilly members get unlimited access to books, live events, courses curated by job role, and more from O’Reilly and nearly 200 top publishers.

Start your free trial

Book description

Today's photographic equipment allows amateurs to take pictures of the stars that far surpass images taken just a few decades ago by even the largest observatories-and this book will teach you how.

Author and world-renowned astrophotographer Thierry Legault teaches the art and techniques of astrophotography: from simple camera-on-tripod night-scene imaging of constellations, star trails, eclipses, artificial satellites, and polar auroras to more intensive astrophotography using specialized equipment for lunar, planetary, solar, and deep-sky imaging. Legault shares advice on equipment and guides you through techniques to capture and process your images to achieve spectacular results.

Astrophotography provides the most thorough treatment of the topic available. This large-format, richly illustrated book is intended for all sky enthusiasts-newcomers and veterans alike.

Learn how to:

  • Select the most useful equipment: cameras, adapters, filters, focal reducers/extenders, field correctors, and guide telescopes
  • Set up your camera (digital, video, or CCD) and your lens or telescope for optimal results
  • Plan your observing sessions
  • Mount the camera on your telescope and focus it for razor-sharp images
  • Polar-align your equatorial mount and improve tracking for pin-point star images
  • Make celestial time-lapse videos
  • Calculate the shooting parameters: focal length and ratio, field of view, exposure time, etc.
  • Combine multiples exposures to reveal faint galaxies, nebulae details, elusive planetary structures, and tiny lunar craters
  • Adjust contrast, brightness, light curves, and colors
  • Postprocess your images to fix defects such as vignetting, dust shadows, hot pixels, uneven background, and noise
  • Identify problems with your images and improve your results

Table of contents

  1. Cover Page
  2. Title Page
  3. Copyright Page
  4. Acknowledgements
  5. Table of Contents
  6. Foreword
  7. Chapter 1 Astrophotography without a Telescope
    1. Cameras and Settings
    2. Camera Mounts and Settings
    3. Astronomical Subjects
      1. Planetary Conjunctions
      2. Constellations and the Milky Way
        1. The Fisheye: A Unique Lens
      3. Comets
        1. Increasing the Exposure Time
      4. Star Trails
      5. Meteors
      6. Zodiacal Light
      7. Polar Auroras
      8. Lunar and Solar Eclipses
      9. Artificial Satellites
        1. The International Space Station
        2. Iridium Flares
        3. Geostationary Satellites
    4. Processing and Touch-Ups
      1. Creating Panoramas and Mosaics
      2. Making Time-Lapse Movies
  8. Chapter 2 Cameras for Astrophotography
    1. The Sensor
      1. Sensor Structure
    2. Image Acquisition
      1. Exposure Phase
      2. Reading and Digitization Phase
      3. Quantum Efficiency and Spectral Sensitivity
    3. Color Sensors
    4. Types of Cameras
      1. CCD Cameras
      2. Consumer Digital Cameras
      3. Astronomical Video Cameras
    5. Computers
  9. Chapter 3 Image Calibration and Compositing
    1. The Components of an Image
      1. The Thermal Signal
        1. Electroluminescence
      2. The Bias Signal
    2. Uniformity Defects
      1. The Causes and Properties of Uniformity Defects
    3. Calibration of an Image
      1. Correction of the Thermal Signal
        1. Acquisition of a Dark Frame
        2. The Adaptive Dark
      2. Correction of the Uniformity Defects
        1. Making a Flat-Field Frame
        2. The Conditions for a Good Flat-Field Frame
        3. How the Flat-Field Correction Works
      3. Image Calibration
        1. Calibration of DSLR Images
        2. The Calibration of Video Images
    4. Noise and Its Reduction
      1. The Sources of Noise
        1. Noise Behavior
        2. Bit Depth and Noise
    5. Photosite Size and Image Quality
      1. Improving the Signal-to-Noise Ratio
    6. Compositing Methods
      1. Compositing by Sum and Median
        1. Compositing by Sigma-Clipping
    7. Reduction of Noise on a Single Image
    8. Advice for Image Calibration
  10. Chapter 4 Using Your Equipment
    1. Attaching the Camera to the Telescope
      1. Piggyback Attachment
      2. Prime Focus Attachment
      3. Increasing the Focal Length
        1. Amplification Factor of a Barlow Lens
        2. Amplification Factor of an Eyepiece Used in Projection
      4. Use of Focal Reducers
        1. Reduction Factor of a Focal Reducer
      5. Afocal Attachments
      6. Attaching a Photographic Lens to a Camera
        1. Attaching to a Video or CCD Camera
        2. Attachment of a Lens to a DSLR Body of a Different Brand
    2. Calculating the Field and Pixel Resolution
      1. Calculating the Field of an Image
      2. Calculating the Sampling and Size of Objects
    3. Telescope Collimation
      1. Tips for a Good Collimation
      2. What Adjustment for What Telescope?
    4. Focusing
      1. Focusing Tolerances
      2. Focusing Systems
      3. Tips and Tricks for Good Focusing
        1. Focusing in Live View
        2. Focusing on a Star
        3. Measuring the Focusing Position
        4. The Parfocal Eyepiece
  11. Chapter 5 The Planets and the Moon
    1. Telescopes and Resolution
      1. What Are the Limits of Resolution?
      2. Telescopes for Planetary Imaging
      3. Chromatic Aberration
      4. The Effect of a Central Obstruction
      5. Collimation
      6. Mounts and Tracking
        1. Fixed Mount
        2. Motorized Equatorial Mount
        3. Motorized Azimuthal Mount
      7. The Atmosphere
    2. Cameras and Settings
      1. Focal Length and Sampling
      2. Image Capture at the Telescope
    3. Processing the Images
      1. Select and Stack the Best Images
      2. Calibrating, Registering, and Combining Images
      3. Enhancement of Details
      4. Color Adjustment
      5. Animations
      6. Stereo Images
      7. The Purpose of Image Processing
        1. The Trap of Overprocessing
    4. The Planets and Their Satellites
      1. Mercury
      2. Venus
      3. Mars
      4. Jupiter
      5. Saturn
      6. Uranus and Neptune
      7. The Satellites of the Planets
    5. Photography of the Moon
      1. Lunar Close-Ups
      2. The Peculiar Movement of the Moon
      3. Photographing the Whole Lunar Disk
      4. The Earthshine
      5. Lunar Eclipses
      6. Lunar Occultations
    6. The ISS
  12. Chapter 6 The Sun
    1. The Sun in Broadband Light
      1. Using Broadband Filters
        1. The Aperture Filter
        2. The Herschel Wedge
      2. Cameras, Imaging, and Processing
        1. The Problem of Daytime Turbulence
        2. The Orientation of Solar Images
    2. The Sun in Hα
      1. The Hα Interference Filter
      2. The Calcium K Filter
      3. Cameras, Imaging, and Processing
        1. Disk or Prominences?
        2. Colorization and Animations
        3. Mosaics
    3. Solar Eclipses
    4. Solar Transits
    5. The Characteristics of a Solar Transit
    6. Equipment and Settings
  13. Chapter 7 Imaging Deep-Sky Objects
    1. Telescopes for Deep-Sky Photography
      1. Focal Length and Focal Ratio
      2. Field Coverage
        1. Photographic Lenses
        2. The Newtonian Telescope
        3. The Refractor
        4. The Cassegrain Family of Telescopes
        5. Other Optical Formulas
    2. Collimation
    3. Mounts for Deep-Sky Imaging
      1. Fixed Mounts
      2. Motorized Alt-Az Mounts
      3. Motorized Equatorial Mounts
        1. The German Mount
        2. The Fork Mount on an Equatorial Wedge
        3. The Dobsonian Telescope on an Equatorial Wedge
    4. Polar Alignment
      1. Using a Polar Finder
      2. Computerized Polar Alignment
      3. Alignment with the Telescope Finder
      4. Refining the Polar Alignment
        1. The Bigourdan Method
        2. The King Method
    5. Tracking Errors
      1. Periodic Drive Errors
      2. The Other Tracking Errors
    6. Guiding the Exposure
      1. Parallel Guiding
      2. Off-Axis Guiding
        1. Autoguiding
        2. Cameras and Software for Autoguiding
        3. The SBIG Adaptive Optics (AO) Systems
        4. Is Autoguiding Mandatory?
    7. Deep-Sky Objects
      1. Stars
      2. Diffuse Nebulae
      3. Planetary Nebulae
      4. Galaxies
      5. Comets
      6. Asteroids
    8. The Atmosphere
    9. Color, Black and White, and Filters
      1. Broadband Filters
      2. Narrowband Filters
      3. Light-Pollution Filters
      4. DSLRs: Infrared-Blocking Filters and H-Alpha
    10. Selecting and Setting the Camera
      1. DSLR or CCD Camera?
      2. What Exposure Time?
      3. The Other Settings
    11. Finding Objects
      1. Centering with a Finder
        1. Centering through the Telescope
        2. Centering with Coordinates Circles
        3. Centering with a GOTO System
    12. Imaging
      1. Preparing for the Imaging Session
      2. The Dithering Technique
    13. Processing the Images
      1. Calibration
      2. Registration and Stacking
      3. Gradient Removal
      4. Levels and Curves
      5. Improving Sharpness
      6. Noise Reduction
      7. Cosmetic Touch-Up
      8. Mosaics
    14. Color Processing
      1. Processing the Colors of Stars and Galaxies Photographed with a Color Sensor
      2. Processing the Colors of Stars and Galaxies Photographed with a Monochrome Sensor and LRGB Filters
      3. Processing the Colors of Emission Nebulae Photographed with a Color Sensor
      4. Processing the Colors of Emission Nebulae Photographed with a Monochrome Sensor Using RGB or Narrowband Filters
  14. Appendices
    1. Appendix 1: File Formats and Operations
      1. Common File Formats
        1. TIFF Format
        2. JPEG Format
        3. GIF Format
        4. RAW Format
        5. FITS Format
        6. Proprietary Formats
        7. AVI Format
        8. SER Format
        9. Format Conversions
      2. Displaying Images
      3. Common Operations on Images
        1. Arithmetical Operations
        2. Resizing
        3. Inversions
        4. Windowing
        5. Rotations
        6. Translations
    2. Appendix 2: Astronomical Cameras and Software
      1. Video and CCD Cameras
        1. Apogee
        2. Atik Cameras
        3. Celestron
        4. Finger Lakes Instrumentation (FLI)
        5. IDS Imaging Development Systems
        6. The Imaging Source
        7. Lumenera
        8. Point Grey
        9. Quantum Scientific Imaging (QSI)
        10. Santa Barbara Instrument Group (SBIG)
        11. Starlight Xpress
      2. Filters and Photographic Accessories
      3. Astronomical Software
    3. Appendix 3: From the Sensor to the Image
      1. Readout of the Image
      2. Obtaining a Color Image
      3. Black-and-White Mode with a Color Camera
    4. Appendix 4: Uniformity Defects—Causes and Remedies
      1. Vignetting
        1. Vignetting Caused by a Camera Adapter
        2. Vignetting Caused by a Filter
      2. Dust
    5. Appendix 5: Checking and Adjusting an Equatorial Mount
      1. Measuring the Periodic Error
      2. Adjusting the Mount
    6. Appendix 6: Making Eclipse Sequences
      1. Preparing for Imaging
      2. Assembling the Frames
        1. The Orientation of the Disks Taken in Equatorial Mode
        2. Lunar Beads Centered on the Shadow of the Earth
    7. Appendix 7: Optimizing the Camera Settings
      1. Optimum Individual Exposure Duration for Deep-Sky Imaging
      2. Optimal DSLR Deep-Sky ISO Setting
      3. White Balance Coefficients Applicable to DSLR (RAW) and RGB Imaging
    8. Appendix 8: Meteor Showers
  15. Footnote

Product information

  • Title: Astrophotography
  • Author(s): Thierry Legault
  • Release date: June 2014
  • Publisher(s): Rocky Nook
  • ISBN: 9781492015611