Astrophotography Skills – Calibrating and Stacking Images Page

Page not written yet

Outline of what it will contain:

• What problems are we solving?
  • Noise
    • Camera noise
    • Atmospheric noise
    • Unwanted objects
  • Uneven light
    • Non-flat optics
    • Dust spots
• Calibration Techniques
  • Bias frames
    • What are they
    • How to collect them
    • How many?
    • Pre-combined masters
    • Temperature libraries
  • Dark frames
    • What are they
    • How to collect them
    • How many?
    • Pre-combined masters
    • Temperature libraries
  • Flat frames
    • What are they
    • How to collect them
    • How many?
    • Pre-combined masters
    • Libraries don’t apply
  • Stacking
    • Combining multiple exposures to
      • Detect and eliminate spurious light
      • Average-out background noise
      • Increase effective exposure
• Usual order of operation
  • Bias-adjust Dark frames
  • Dark-adjust all exposures
  • Flat-adjust all exposures
  • Stack exposures
    • If filtered monochrome: stack groups per filter
    • Steps
      • Reject bad images
      • Align images
      • Combine images
        • Selection of math formula
  • Colour combination
    • If filtered monochrome, combine colours last
  • Post-processing
    • Move to image processing software and fine-tune
    • Some prefer to do 3- or 4-colour combine in the image processing software