PSF photometry missing info

[stefanocovino]

Dear friends,

I have managed to derive reliable (hopefully) PSF photometry building an ePSF, however I think there could be additional pieces of information that could be profitable added to the documentations.

. First of all, unless I am very wrong, I think the total flux reported for the PSF photometry can be related to the real counts on the frame by dividing it with the oversampling factor**2 used to compute the ePSF. This is mentioned somewhere in the replies to these issues, however it is not a minor point.

. Second, and related to the first, in any case it might be useful, ad it can be don with DAOPHOT for instance, to have PSF photometry within a given radius. It might help for calibration, for instance. The only way I found for this, again if I am not wrong, is to compute circular photometry in the epsf.data array, using a radius multiplied by the oversampling factor. Given that the pdf is normalised to 1, the obtained flux is the aperture correction to have te PSF photometry within the chosen radius. Assuming what I did is correct, this could be a useful addition to the code.

Thanks anyway for your amazing work.

Stefano