Collimation tool (exptl)

[timh]

Hi Robin, Just to comment that I have been using this and it seems quite useful. The contour markings are a bit hard to see (yellow perhaps rather than red?)

Wonder whether the analysis might (depending on exposure length) sometimes be better applied to integrations of a few aligned frames rather than
individual frames? With the rather short frames that I was testing the results tended to be all over the place in terms of finding a pattern in individual frames -- but a pattern did emerge when I looked at stacked sets (using the folder camera and the SC stacked fit files).

It is called a collimation tool but I wonder whether it's potential use is more general than that ..i.e useful for detecting tilt and incorrect backspacing of flatteners with respect to the sensor? and whether then it might be better to also detect some function of ellipticity ? e.g. Maybe always have FWHM values based upon the most pessimistic long axis of any ellipse rather than averaged?

best wishes
Tim

[admin]

Hi Tim,

yes, I guess the name comes from what I was trying to achieve when I first wrote this code (it works too, until you add a coma corrector, after which it doesn't really work very well any more...). However, you can definitely use it for tilt detection etc in theory. I must admit that I like the idea of using it on a stacked image, which would reduce the variability that is often present unless a very strong signal is present in the star FWHM patterns. I will have to think about how that might happen.

cheers,

Robin