RECENTERING GENERATING DUPLICATE FITS FILES

[MikeHuerto]

Hi Robin
This is very strange. I was Livestacking with recentering centering enabled, and SC started to generate 5 to 6 copies of each frame (FITS files). I was taking 60 sec exposures,starting at 11:50 pm and stopping at 12:08 (so i ended up with doxens of duplicate frames) . When I check the FITS header in Pixinsight, it indeed say they are 60 second exposures. When I rerun them through the SC camera folder, it also says they are 60 sec exposures. But it clearly impossible to have 5 x 60 seconds fit in 1 minute

I´ve attached a screen shot of the capture folder, and the log for that time period (11:50 pm, and the session immediately before, and it looks like its happening during the recentering action. Any idea whats causing this?

Ive been using your great software for over 4 years, and never seen this before - the only thing I can think of was, that I had a problem with the meridiam flip, and had been closing and restarting sharp cap repeatedlly. From a practical point of view, Ill just go through and delete the duplicates-

Best

Mike

[admin]

Hi Mike,

I think you just need to change the live stack setting for which frames are saved - during the recenter, SharpCap reduces the exposure to 2s to avoid having to wait for a 60s frame to finish when the recenter is complete. It looks like the 2s frames are being saved, which means that your 'Raw Frames' saving setting must be 'Save All', which does what it says... Change that setting to 'Save stacked' or 'Save except when paused/dithering' and it should be fine...

That is, unless you already have it as 'Save except when paused/dithering' and there is a bug which means a recenter is not treated in the same way as a pause/dither. If that's the case, I will need to fix it.

cheers,

Robin

[MikeHuerto]

Hi Robin
I did have it set to Save All. But the duplicates are not 2 sec exposures, they are 60 secs, according to both the FITS header and the visual intensity of the stretched image. Is it possible that there´s a bug that´s using the last image to recenter, and then saving a copy of that same image. Thats what seems to be happening. Here is a link to 3 of the 60 second frames all showing exactly the same time in the FITS header of 11:50 pm local time, or more exactly 04:49:01.6103964 UT. So they indeed appear to be duplicates. Sharpcap would not let me upload the files directly. It didn´t like the fits header, and/or they are too big at 22.3 MB.

There are a total of 10 frames, numbers 24 to 33, with exactly the same 11:51 pm time stamp in the FITS header, and then another 10 at 11:51, 4 at 11:52, 5 at 11:53, 8 at 11:54 etc etc etc. Each time they have the same time stamp as the first in the series.

https://www.dropbox.com/scl/fo/lk8yzgpt ... 579ja&dl=0

By the way, these image are of the Tarantula nebula and the LMC, taken with a Samyang 135 lens attached to an ASI294MC on a SW GTi SA mount. It makes a great travel rig ... while Im here in Peru!

Best

Mike

PS. This bug seems similar to that reported here: viewtopic.php?t=8388

[admin]

Hi Mike,

Ok, so the fact that you get the files saved is down to the 'Save All' option being selected, but it *is* weird that they are they full exposure frames rather than the 2s exposures that you would expect. Looking at the three files you sent, they are *identical* apart from two things...

* The comment on the 'SIMPLE' FITS header, which records the time at which the fits file was saved rather than the frame time
* The equinox header, which also looks like it records the time of the save (as a fraction of a year).

Looking at the SIMPLE comment, the timestamps are about 2s apart, which ties in with the idea of short exposure dither frames, also we see this sort of message in the log at about that interval while recentering

Code: Select all

Info   	23:50:14.445314	#27	Live stacking paused : Frame captured while recentering	
Warning	23:50:14.445570	#27	Frame not stacked because : Frame captured while recentering	

So I guess the question is... 'Why is the 60s frame being replayed multiple times at this point rather than the expected 2s frames'? I haven't got a good answer for that at this point...

Do you have a 'CaptureSettings.txt' from something that you saved during that live stack session? That should contain not only the camera settings but also the live stack settings that were in use - it would give me a good chance of setting up a very similar configuration to test with.

Good to hear that your travel rig is working nicely - I have heard good things about the Samyang 135 lens from a few people and was considering a GTI mount at one point for a lightweight setup. In the end I went with an iOptron SkyHunter, but mostly because I thought it would be useful to have an iOptron mount to test with rather than a second Skywatcher one.

cheers,

Robin

[MikeHuerto]

HI Robin

I have just placed 5 text files from¨Save Exactly As Seen¨ in the same Dropbox folder. I assume that it was you are asking for. They include all the settings used during Live Stacking. They should all be the same, except for number of frames captured and stacked.

Let me know.

Best

Mike

[admin]

Hi Mike,

first two things I noticed are

1) Your SharpCap version is from last August and there have been a lot of fixes/improvements since then. Please could you update to the latest and see if that helps the issue at all (even if not, at least when I try to debug it I will be debugging the same code that you are running).

2) The 'WithDisplayStretch' settings files from live stacking don't have the live stack settings in them! That's a bug that I will try to fix for next week, if you use 'Save with Adjustments' (or save as 16/32 bit stack) then that should create a settings file that *does* contain the info on the live stacking options that are set, which will be useful if the initial problem is still happening in the latest code.

cheers,

Robin

[MikeHuerto]

Hi Robin
Ok.will update.
I tend to think it was some kind of one off bug -

The earlier session I did from 8:30 pm to 10:30 pm did no show this behaviour. Maybe I accidently changed something - but either way will let you know if I see it again.

Best

Mike