Information and settings for Andor/Apogee Alta CG16M

Camera parameters

  • Name: Apogee Alta CG16M
  • Gain: 1.45 electron/ADU
  • read noise: 9 electrons
  • dark current: 0.01 electron/pixel/sec typical, but there are hot pixels
  • linearity limit: 35000 ADU
  • Pixel size: 9 micron
  • Number of pixels: 4096 x 4109 (includes overscan)

Reduction settings

All images

  • Do not use the overscan
  • Trim to all of first axis, 4096 on second axis

Reducing bias images

  • Only need to trim

Combining bias

  • Choose sigma clipping, upper and lower bounds of 5.
  • Combine using mean/average

Reducing darks

IF THE DARK EXPOSURE TIME DOESN'T MATCH ANY OF The OTHER IMAGES:

  • Trim
  • Subtract bias

Combining darks

  • Choose sigma clipping, upper and lower bounds of 5.
  • Combine using mean/average
  • Group by exposure time

Reducing flats

  • Trim
  • Subtract bias
  • Subtract dark
    • Scale by exposure time

Combining flats

  • Choose sigma clipping, upper and lower bounds of 5.
  • Combine using mean/average first, BUT if there are stars in the combined darks then use median instead.
  • Scale before combining
    • by median
  • Group by filter

Reducing science (light) images

  • Trim
  • Subtract bias
  • Subtract dark
    • Scale by exposure time
  • Flat correct