Posted by Andrea Tasselli at 14:40 on 2012 Sep 10
Just to clarify further; IRIS does NOT use in any form or fashion 32-bit deep images nor it is capable to read them. It only recognizes 8 and 16-bit deep images and uses 16-bit *signed* FITS files (or PIC) up to 3 planes per image.IRIS (and all the software I know of) will happily align and stack calibrated and UN-calibrated frames, so it is up to the user decide what to do.As long as there are 3 stars shared between all the frames IRIS is more than capable to align and stack them. In fact they do not have to have been taken with the same hardware *at all*, as long as there are enough stars to perform trasformation (to a common scale), alignment (with possible morphing) and stacking.Andrea T.