Settings for stacked spectrums in different versions of Siril.

With Siril 1.03 using the one star registration setting and a small box around the zero point star, I could then sum stack mono spectra of stars taken with the slitless Star Analyzer filter and see the stacked spectrum in the spectroscopy software RSPEC.

With version 1.21 and the same stacking settings, the registering and stacking are reported by Siril to have worked correctly but the stacked fits image just results in two points with no spectra in RSPEC. A fits viewer (Astropixel Processor) shows that the stacked 1.21 spectrum image looks to be intact and I have checked and there appears no issue deriving from the file name itself.

When I wrote this query a few minutes ago I thought Siril 1.21 was somehow changing the properties of the registered or stacked fits files differently to Siril 1.03. But now that I have removed 1.21 and reinstalled 1.03, I am having the same problem so it seems to be some subtlety in the Siril registration or stacking setting although there is not many options there to get wrong.

A bit more progress on this issue, I find if I use a file converter to change the stacked Siril fits file into 16 bit format, it now seems to work in RSPEC (RSPEC is supposed to work with 32 bit files and I did have the RSPEC 32 bit option enabled)

Unless I have just been unlucky with my choice of stars or conditions I am not sure what I can do.

While I am here, this may well have been asked before but since Siril is fussy about numbering, it would also be nice if there was a functionality to convert a lot of camera image files to a numbered sequence or perhaps have an option for Siril be less fussy about differing characters (temperature etc) in the file names prior to the end number.


Without screenshots, or more illustrations, it’s very difficult to understand anything and help.

Ah yes, agreed, my post would not make sense to a general Siril user. I thought perhaps Siril Spectroscopy users might have been on top of the ins and outs. But when I started this post, even while I am a Siril beginner, it seemed clear cut there was a modern Siril issue, in particular since most spectroscopic stackers report only using old versions of Siril which cannot be ideal in the long run.

However the particular issue that is bothering me, I discovered as I wrote the post is related to Bit depth and I have become uncertain at this time whether the issue the reading of stacked files is in fact due to Siril or perhaps it derives an error in the current version of spectroscopic software Rspecs handling of 32bit files. Perhaps I should take this down post until I have explored more whether the error is RSpec related?