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NOTCam K' filter

NOT filter number:206
Dimensions:25-mm round.
Filter name:K'
Marking on filter edge:
Cosmetic defects:

on: 1.941 micron
off: 2.292 micron
FWHM: 0.351 micron

  • Transmission curves: gif image, ASCII data
    Note:These transmission data have been scanned from the manufacturer's hardcopy. They are probably good to a couple of %. Details of the scanning procedure are not known, but the scan was made at ambient temperature. A small shift to the blue will be effected at operating temperature.

  • Notes: Purchased as part of the Gemini NIR filter consortium.

  • About the K' filter: This filter was designed with the passband located a bit shortward of the standard K band in order to lower the thermal component of the background. See: Wainscoat & Lennox (1992, AJ 103, 332) for reference. Its short cut-on wavelength was intended to take advantage of the reduced water-vapour extinction above Mauna Kea (see: Handbook of IR astronomy, Glass, 1999).
  • Back to top Last modified: June 28 2023