How do people deal with having multiple bias, dark, and flat for a single target? Pixinsight can group images by keywords, I believe either in the file name or in FITS keywords. I prefer not to add anything to my file names - they are already too long.
Is there a way in SGPro to add FITS keywords, like B=20220808 for the bias frames taken on Aug 8, 2022? I didn’t see anything in the help file.
It is not necessary to store all info in the file name, you can store parts in the folder structure as well.
This is my setup:
%ds%tn%ft%fe_%dt_%tm_%bi_%el_%03
So, sequence start date, target and frame type are stored in the folder structure, while filter, frame timestamp, binning, exposure and frame number are stored in the file name.
Your image processing software can be pointed to the relevant folder for each frame type.
I wasn’t clear enough with my question.
If, for example, I have 2 sets of flats for a target and I name the flats with the date they were taken, how do I tell Pixinsight which flat to use with which images, without putting info in the file/path name? If there was a way in SGPro to embed FITS keywords, I’d embed the flat, bias, and dark dates and then group on them in Pixinsight. When ever I took new calibration frames I’d update the dates in SGPro.
Sorry, can’t help you there as I do not use PixInsight but AstroPixelProcessor instead. APP understands the concept of sessions where you can indicate which lights and flats are from which session and it will then calibrate those lights only with the relevant flats. Same for bias and darks, but those are likely be used as one for sets for all sessions regardless. Is this concept not available in PixInsight?
Pixinsight can group frames by fits keywords and by keywords in the path or filename. You can make subfolder in which you use for example “folder_BIAS-20220812” and then define in pixinsight keyword BIAS.
Edit: See also this What is the "variable" box at the bottom of the equipment other category?
@drvo, I agree with you that having the ability to add custom FITS fields would be nice, for the same reason you mentioned in the other post.
I’m aware of Pixinsight’s ability to group by directory/filename, but I’m trying to avoid that since the names get unwieldy when you add FLAT_YYYYMMDD, BIAS_YYYYMMDD, and DARK_YYYYMMDD. That also means in many cases I’ll need to manually separate images in a target.
I make BIAS and DARKs only once a year and I use keyword FSEQ for FLATS which I take every 1-2 weeks. I give the FSEQ keyword to the “Directory” path and after each day I copy the files to the processing PC to the “correct” folder. At this step I deletes bad images (high HFR, clouds). This eliminates many problems and manual sorting in preprocessing.
I generally calibrate all of my subs as soon as they are taken, using the appropriate flats/darks from that session. That way, when post processing, the calibration is already done and you just proceed direct to stacking. You could potentially automate this, by writing a script that gets called after each event in the sequence completes.
Rather than trying to imbed the image data in the file name, why not just use standard computer file management techniques? I image with two different cameras and three different scope configurations: QHY163M and QHY168C cameras; 130mm APO, 12" Meade ACF at F8 and at F6.
This requires an extensive set of flats and darks. Using directory names to group the calibration frames by category makes it easy to tell PixInsight what files to use when processing my images:
Charlie
Charlie,
I have my calibration frames in a directory structure similar to yours. The question is, how does Pixinsight know which calibration frames to use which each light?
PixInsight matches “lights” to darks based on exposure time. So if you have 600 second light frames, PI looks for 600 second dark frames. For flats, PI matches flats to lights based on filter name. Also, the binning levels must match. PI has a “Calibration Exposure Tolerance” value that can be used to force a match; eg, put 300 in the exposure tolerance if you have 600 second lights and only 300 second darks – not recommended. Of course, this might be acceptable if you are shooting 35 second light frames and have 30 second darks.
I have found it useful to have standardized exposure times; that is, I only shoot 300, 600 and 900 second exposures. This keeps the library of darks reasonable.
Charlie