来自Diffraction(Sbig) CEO的劝告

Basic Calibration
Keep it simple – same basic math as for CCDs.

  • Output Image = (Light – Dark) / Normalized (Flat – Flat-Dark)
  • Take all calibration and light frames at the exact same sensor temperature, including flats.
  • Use the exact same gain levels and sensor operating modes for all frames.
  • Do not use bias frames.
  • Do not use exposure scaling.
  • Take dark frames matching your light frames.
  • Take dark frames matching your flat-field frames.
  • Use lots of frames.
  • Calibrate your flats using matching master dark frames.
  • Calibrate your lights using matching master dark frames.
  • Try different flat-field exposure times (and flat-darks) and compare results quantitatively.
  • Finally, as described above, if you like to reuse calibration frames for a period of time, be aware that large ambient temperature changes or even a simple firmware update could potentially change the camera characteristics. This may require reshooting calibration sets more frequently than you are used to.

Doug George
President/CEO and Lead Engineer
Diffraction Limited