In VPhot using the Time Series photometry there is the option to fix the aperture.
What settings do the sky annuli use as these have no option to change in TS?
I’m getting some differences between Single image photometry and TS in the measured mags for the same aperture.
The sky annulus settings in the Tools settings are used in TS. It is only the measurement aperture that will change IF you are using aperture = 1.5x FWHM? Yes, you may get some mag differences between single image and time series.
I usually inspect the Single image photometry(SIP) FWHMs and pick a fixed aperture to suit.
Right or wrong I have done similar in the Time Series and always used a fixed (number of pixels) aperture, not 1.5x FWHM. (I assume the latter adjusts each Co, Ck and target to 1.5x its FWHM.
This latter approach seemed rather different from SIP so I avoided it.
Should I use 1.5x FWHM in Time Series?