Saving Idividual Frames

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CraigG
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Joined: Thu Nov 29, 2018 11:37 pm

Saving Idividual Frames

#1

Post by CraigG »

Hello all!

Before starting a live stacking session, I check the "Save Individual Frames" box so I can process the raw frames later in DSS and Nebulosity. This selection has always worked for me. Unfortunately, after finishing my session last night, I was unable to find more that a couple of saved frames in the usual " Capture" folder for yesterdays date.

I did try it a few minutes ago with the Test Camera 1 and the individual frames saved just fine in the Capture folder. Still not saving when using my Horizon OSC.

So, not sure what I dId wrong if anything. I haven't changed any settings that I know of and I obviously would like to solve this before heading out again. Any thoughts?

Thanks!
Craig
chongo228
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Re: Saving Idividual Frames

#2

Post by chongo228 »

Only easy answer I know of is frames that SC can't align and drops will not be saved....even if they look fine. With the new dithering reduced exposure method It might be had to know if your drop framed count was due to dithering of actual dropped frames.

I had this happen a few times...I adjusted settings and finally fixed it. SC was picking up plenty of stars but I believe it would sometimes lock onto very bright stars that were bloated and wouldn't be able to align properly. I lost a lot of data until I fixed it. I backed the maximum star size down to 12 (I think....on my work computer). I also moved the min star size just above default. This cuts the outliers out leaving only stars in the middle. I think I also raised the black level slightly. I remember the night I was adjusting everything my star count went from 400-500+ to around 130-150.
CraigG
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Joined: Thu Nov 29, 2018 11:37 pm

Re: Saving Idividual Frames

#3

Post by CraigG »

Thanks Chongo228!

That makes sense and would explain why my camera won't save individual files when testing indoors without any allignment. However under the stars last night my sub frames were aligning and stacking just fine with only one or two dropped over about a half hour session. Nothing seemed to be out of the ordinary from all of my other sessions where the individual files saved as expected with the same star detection criteria, etc. It seems like maybe there's some type of limit on the number of individual files that are complied in the Capture, Raw Files folder when using my camera? It's weird because I haven't changed anything that I know of to cause it to go kitty wampous!

Thanks,
Craig
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admin
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Re: Saving Idividual Frames

#4

Post by admin »

Hi,

Are you sure about this? As far as I can see from the code the raw frames are saved before the decision about whether or not to stack each frame is made, so really they shouldn't be skipped if a particular frame doesn't make it into the stack. The only thing that disables the saving of the raw frames is if the stacking is paused (either manually or due to dithering being in progress).

Cheers, Robin
mAnKiNd
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Re: Saving Idividual Frames

#5

Post by mAnKiNd »

As a parenthesis, there seems to be a discrepancy in the documentation here:

http://docs.sharpcap.co.uk/3.2/16_LiveStacking.htm

And here:

https://docs.sharpcap.co.uk/3.2/#The%20 ... 0Interface

"Save Individual Frames – when enabled save each frame as a separate file (FITS/PNG). Note, that only the stacked frames are saved. The individual frames will be found in a folder like YYYY-MM-DD\Capture\HH_MM_SS\rawframes"

Cheers,
Minos
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Re: Saving Idividual Frames

#6

Post by admin »

Hi Minos,

Thanks for pointing that out – that's now the documentation bug. The behaviour there changed back in September 2016 to address an issue where the so-called raw frames were actually partially processed. The most appropriate fix was to change the saving point for them to be before the processing happens, which means that they no longer only include those that are included in the stack.

The current code will save all raw frames if saving of them is enabled except while the stack is paused.

I'm tempted to introduce a more comprehensive option here – the choice between saving all, all except when paused, stack frames, or none. Comments welcome.

Cheers, Robin
mAnKiNd
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Re: Saving Idividual Frames

#7

Post by mAnKiNd »

Cheers Robin,

I for one would greatly welcome a "save only stacked frames" options, as I find the FWHM and brightness filters a powerful utility, the former of which I tend to tweak and fine-tune during live stacking and the latter left on auto to reject cloudy frames. This filtering advantage is lost when all individual frames are saved, as you have to perform double duty and filter through them again when selecting which ones to stack and process offline.

Having a "save only stacked frames" throughput would save on space and time (no fabric of the universe pun intended), because of less frames to deal with during offline processing. For example, ASI183MM-P frames are 40mb each at Bin1x1 and space gets eaten up pretty quickly after a few sessions and the time it takes to calibrate and stack all these frames is lengthy, couple of cups of tea at least...

Kind regards,
Minos
CraigG
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Re: Saving Idividual Frames

#8

Post by CraigG »

An update...

Had a successful imaging session last night with the Stack Individual Frames function working flawlessly! I suspect the previous nights failure may have been due to my Horizon OSC being starved for power. I switched out the car starter jump box that I've been using without incident for a couple of years to a full size deep cycle marine battery. Could it be that the camera had enough power to provide an image to stack but not enough to save while starting another frame?

Anyway, we're back in business and I really appreciate everyone's input. Take care!

Craig
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Re: Saving Idividual Frames

#9

Post by admin »

Hi,

I've been looking into this problem this morning and discovered some interesting things. One is that although every frame (except while paused) is saved, if you have used {StackedFrames} in the filename template for your raw frames and haven't included something like a time stamp then frames will overwrite each other at times when the frame is not being added to the stack (basically if a frame is not added then the stacked frames count doesn't go up, so the next raw frame will be written over the previous one). The workaround for this is to either include the time or to use {Index} or {TotalFrames} instead of {StackedFrames} in the raw filename template. I am changing the default raw filename template to use {Index} to avoid this problem in the default configuration in future.

I have also added a drop down to allow you to choose which raw frames to save – the choices are

Save All : does exactly what it says – all raw frames saved without processing
Save except when paused/dithering : saves all frames except those that arrive while the stacking is paused or dithering. This will include saving frames that do not pass the FWHM or brightness filter.
Save Stacked : only saves those frames that are added to the stack. Frames that arrive while paused or dithering, or frames that do not pass the filtering do not get saved.
Save None: doesn't save any raw frames at all

Additionally, I think I may have been unable to fix the problem where occasionally a short frame captured during dithering was being saved as a raw frame. I'll need user feedback to confirm whether that fix is a complete one or not.

Cheers, Robin
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Re: Saving Idividual Frames

#10

Post by mAnKiNd »

🍻☺️👍
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