when i use getpsf in zpl, the result mentioned that there are np data points, and spaced by micrometers apart. what does it mean? Is it the average position between the psf data points? also, the data spacing reduces as pupil sampling increases. do you have some references for me to better understand this results.
Best answer by Kevin ScalesView original
It looks like you're using the sample code from the GETPSF help page. In that example, the spacing is the exact size of the pixels in the resulting psf plot. The more sampling points you have, the finer the detail in the PSF will be, so the spacing will be smaller per pixel. The ZPL help page emphasizes the syntax of the ZPL keyword, but if you go to the help page titled 'FFT PSF' you can get all the details about the Fourier Transform based PSF function in general, including the sampling and spacing.