Calculate Objective Parameters

Author: Sebastian Rhode (Sebastian.Rhode at
History: 2008/09/10: First version
2008/10/02: Version 1.1
2010/06/22: Version 1.3
Installation: Download Calc_Objective.class to the plugins folder and restart ImageJ.
Description: This plugin calculates parameters of interest for an objective lens. Required Input Parameters are:
  • Objective NA
  • Magnification
  • Focal length of Tube Lens [mm]
  • Wavelength [nm]
  • Refractive index n1 (immersion medium)
  • Refractive Index n2 (medium; 1.33 (water) or 1.36 (cytosol))
  • Desired Fill factor of back Aperture (Beam Diameter = 1/e2) [mm]
  • CCD Pixel Size [microns]
Output parameters are:
  • Focal length of objective [mm]
  • Angle for Total Internal reflection [degrees]
  • Maximum working Angle of objective [degrees]
  • Rayleigh criterion [nm]
  • Spot diameter (1/e) [nm] ~ 0.78 * lambda / NA
  • Spot diameter (1/e) [pixel]
  • Effective Pupil diameter of objective lens [mm]
  • Required beam diameter (1/e2) for Fill Factor = 1 [mm]
  • Required beam diameter (1/e2) for Fill Factor = Desired Fill factor [mm]
  • Pixel Size in Object Plane [nm]