IT logistics

My current logistics regarding the astro pictures are quite simple, ad-hoc: just as I do with my usual photographs (actually, among them), I have a tree structure of directories - a root, under which I have the years, and in there the single days with the photographs. The names of the directories conform to the ISO standard for dates, i.e. YYYY-MM-DD. In the case of Astro stuff, I append “_Astro”, so my wife, and myself too, immediately knows what it's about (for my wife, it means she won't be interested).

Inside the day's directory, if I used separate equipment, I'll have subdirectories per camera (e.g. EOS450D, EOS500D). Under there usually reside the raw pictures, which may be regrouped by subject (e.g. IC405, flats, darks60s, darks120s, Pleiades, …). For the processed images, I'll create a “results” subdirectory in the day's directory, containing the intermediary TIFFs and the resulting JPEG files. In the day's directory, I'll also have a readme.txt file with the notes regarding that day's work - what the conditions were like, equipment used, techniques tried, target objects, which pictures depict which objects etc.

Of course, regular backups are made to an external USB harddrive. Pictures are erased from the camera's SD card only after the backup was made, so I always have at least two copies around.

Idea: instead of keeping the readme.txt's data as prose only, I might create a metadata structure at the start of the file, so as to list e.g. target objects, equipment used, maybe a rating of the quality achieved. This could easily be queried using classic UNIX tools such as find/grep, to locate e.g. when a certain object was pictured, using which equipment.

My current (end of 2015) processing workflow:

• stacking is done using regim, including darks, flats as available. (Note: I'll want to try adding bias frames). The result is stored as TIFF.
• gimp 2.9 is used to crop dark borders
• regim's “remove gradient” is used to flatten the background. (Note: I'm not very happy with the results, I often get strange blotches there).
• fitswork's “flatten background” features are used to flatten the background. (Note: much depends on which precise function is used and what the object is).
• gimp 2.9 is used to stretch the image (levels, curves) and work out the target object
• gimp 2.9 keeps being used for finalizing the image (contrast, saturation, de-noise, …, crop, scale) and exporting it to JPEG

My processing workflow as of end of 2016:

• stacking done using regim, including darks, flats and bias. The result is stored as TIFF. I have tried using DSS, which in some cases gets results where regim fails, e.g. when the ground is part of the picture (e.g. wide-angle with landscape). With DSS, if often get regions in the resulting picture where the stars are not properly overlaid, thus giving blurry results.
• to flatten the background, I use fitswork on Windows. I use “background gradient removal automatic”, then “flatten for nebulas” (or maybe for stars, depending on the subject). Finally, I use “lines to equal values” four times, with a 90° rotation between them.
• GIMP 2.9 is used to crop imperfect borders
• GIMP 2.9 is used to stretch the image (mostly levels, possibly curves) to work out the target object. It is important to not overdo the stretching, I've sinned there with curves especially.
• the “dechroma” plugin for GIMP is used to remove some of the noise and get back a smooth histogram
• final handling with saturation, contrast etc. is done in either RawTherapee or GIMP 2.9, with final exports to JPG

I want to have a more precise look at the LLRG tutorial to improve my workflow.

I also want to have a more detailed look at THELI and its workflow, even if it seems more oriented towards CCD imaging. Oli's THELI page should provide valuable insight, his results are certainly impressive. My own getting started on Theli page.

With the use of a planetary camera, I'm still experimenting, but so far (mid June 2018):

• capture using FireCapture (ASI120MC)
• Use AutoStakkert for the stacking
• run the result through Registax' wavelet filter
• final processing (crop, saturation etc.) in GIMP 2.10

There may be interest to first run the captured video through PIPP.