Multi Night Stacking Question - Forums

Topic starter

Dec 20, 2022

I image with a DSLR and don't have a constant setup, I have to tear down every night. Often the "astro lens" comes off for day shooting. So I shoot new flats with every session. When I go to stack and have data from multiple nights, I want to combine it. I am currently using SIRIL and have yet to figure out how to use SIRILC for multi night shoots. Do I get the same effect by stacking each session and then stacking the resulting .fit files as I would get stacking everything at once?

Thanks,

Benjamin

dkamen

Dec 20, 2022 · Edited: Dec 20, 2022

If the stacks are approximately the same total integration and do not differ drastically in their gradients, yes it is the same effect. If you do background extraction on each integrated sub before stacking them, gradients are much less of an issue.

I use this technique a lot because it is the only practical way to address the gargantuan resource requirements once you go above 200 DSLR subs or so, especially with mosaics.

Another option, assuming your problem is just the different flats, is to save the calibrated subs and use those as your starting point. Many people do this anyway, especially if you change your masters frequently (so it may be difficult to remember which flat goes to which light etc if you revisit the data 1 month later).

Helpful Insightful Respectful

Nick Grundy

Dec 20, 2022

I haven’t used Siril much for stacking but use astro pixel processor for stacking and the multi session options are great. Makes it super easy to assign calibration frames for each night.

Rob Foster

Dec 21, 2022

Benjamin, as a DSLR user who has to setup/tear down nearly every night, I wish I could help you with your specific software; I remember those very same frustrations with other programs. I also shoot flats for every session, and while I don't know your software, I will share that some of these frustrations compelled me to take the plunge on PI for all processing. In PI, I can assign the designation "SESSION" to any folder from a given night (lights, flats, any calibration frames in that folder) and it will segregate the data in preprocessing to allow for inclusion of multiple nights for the final end-integrated image (assuming same camera). For example, one night it might be: 2022-12-20_SESSION_1_M31, and the night night might be …_SESSION_2_… and so on. It does not help your question with SIRIL or SIRILC, but this will allow you to take data from many nights and combine it into a single integrated master if you can assign a keyword to preprocessing similar to PI to segregate your pre-processing. I just shared a revised image of M51 from last year that incorporated data from different nights (and different cameras, though that is a different solution) and it does work! Sorry it does not answer your question, but perhaps others with more facility with your software can comment if that capability exists. Good luck! Rob

Helpful Respectful Engaging Supportive

Related discussions

Objective Way To Tell If I Have Enough Signal In My Single Exposures

Is there an objective way to tell if I am exposing long enough for good signal in my lights? I know the rule of thumb to expose so the histogram in NINA is just off the left side. But I want something more definite than that. I use the NINA Optimal E...

Exposure optimization relevant to multi-night imaging workflow and signal consistency.

Aug 6, 2024

Combining-stacking fit files from different nights

Does stacking two or three fit files, which were acquired using ASILive on different nights, generally produce the same result as one long session and one fit file? For example, if two fit files from different nights, with one having ASILive stacking...

Multi-night stacking with equipment teardown between sessions affects stacking consistency.

Jul 14, 2021

Keywording In WBPP For Multiple Nights, Flats And Dark Flats Not Taking Keyword Like The Lights And Darks

I always seem to have this problem where the flats and dark flats don't seem to take the keyword that the lights and darks do. I usually build my folder structure to include, for example, IC1396_N1, IC1396_N2 and so forth. When I do this the ligh...

Keyword organization directly addresses multi-night flat management in stacking software.

Aug 13, 2024