Save as FITS with Pre-Processing?
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metastable
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Save as FITS with Pre-Processing?
I'm wondering if this is possible or if there's another option that is similar? From the documentation it seems that the only way to save with pre-processing will also save with histogram adjustments, which I'm trying to avoid. I haven't tried this yet but maybe making sure to reset the histogram before saving with adjustments is the way to go?
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admin
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Re: Save as FITS with Pre-Processing?
Hi,
there is some subtlety here.
If you save the RAW frames from live stacking then they are untouched - data as it came from the camera, unaffected by anything in the SharpCap 'Preprocessing' controls or the live stack area.
The pre-processing (dark subtraction, flat correction, gradient removal, satellite trail removal, etc) is done as the individual frames are being added to the stack - that means that the data in the stack has these corrections applied, so any option that you choose when saving the stack will include those corrections.
If you save as a 16 or 32 bit stack, then that's what you get - the data in the stack with no adjustment from the histogram stretch or the live stacking 'Enhancement' controls like noise reduction or sharpening. I think this is what you are asking for.
If you 'Save with adjustments' or 'Save exactly as seen' then you do get the stretch and enhancements included in the saved image.
cheers,
Robin
there is some subtlety here.
If you save the RAW frames from live stacking then they are untouched - data as it came from the camera, unaffected by anything in the SharpCap 'Preprocessing' controls or the live stack area.
The pre-processing (dark subtraction, flat correction, gradient removal, satellite trail removal, etc) is done as the individual frames are being added to the stack - that means that the data in the stack has these corrections applied, so any option that you choose when saving the stack will include those corrections.
If you save as a 16 or 32 bit stack, then that's what you get - the data in the stack with no adjustment from the histogram stretch or the live stacking 'Enhancement' controls like noise reduction or sharpening. I think this is what you are asking for.
If you 'Save with adjustments' or 'Save exactly as seen' then you do get the stretch and enhancements included in the saved image.
cheers,
Robin
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metastable
- Posts: 45
- Joined: Thu Oct 26, 2023 1:24 am
Re: Save as FITS with Pre-Processing?
Thanks for the response. Then it seems what I was hoping for is already taking place. I wasn't aware that the pre-processing was done per frame. That clears it up for me. I've been saving and doing my post on the stack. I've really been enjoying the live stacking feature. Thanks for all the work!
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admin
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Re: Save as FITS with Pre-Processing?
Hi,
yes, the pre-processing such as darks/flats/satellite trails has to be done before the frame goes into the stack - otherwise the alignment with all the previous frames would ruin the match of hot pixels with the dark or shadowed areas with the flat etc.
Never try to do dark/flat/bias processing on the saved stack images - that won't work at all well due to the above. Stretching, noise correction, colour balancing, etc are the processing steps needed after the stack is saved.
cheers,
Robin
yes, the pre-processing such as darks/flats/satellite trails has to be done before the frame goes into the stack - otherwise the alignment with all the previous frames would ruin the match of hot pixels with the dark or shadowed areas with the flat etc.
Never try to do dark/flat/bias processing on the saved stack images - that won't work at all well due to the above. Stretching, noise correction, colour balancing, etc are the processing steps needed after the stack is saved.
cheers,
Robin