Trying to get better view of results

Discussions of Electronically Assisted Astronomy using the Live Stacking feature.
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givoly
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Joined: Tue Aug 31, 2021 9:01 am

Trying to get better view of results

#1

Post by givoly »

I'm fairly new to EAA and to SharpCap Pro.

However, my desire is to get as close as possible to the results of astrophotography - but not with hours of post processing, instead, to see it live in the field with EAA using SharpCap Pro.

What has been frustrating for me is that the same raw data (saved raw frames, calibration frames, etc.) can produce MUCH better results with a bit of processing in photoshop compared to how I see them on screen.

Is there something I can do within SharpCap Pro to get closer to the result after post-processing the same raw data?
I think alignment in SharpCap is perfect. Stacking and noise reduction, as well. The issue is post-processing the result for display. I don't have enough controls there. Only histograph, a bit of sharpening and (in-this-case-unnecessary) noise reduction.

As an example, here is what I see on screen with best settings I could figure out vs. after DSS+PS for same raw material (90x15sec subs with 10bias/10dark at ISO6400 on unmodified Canon T7i with 100mm/f/2.8 @ f/5.6 LAOWA lens placed on iOptron SkyGuider Pro).

On screen:
M22 sharpcap screenshot.png
M22 sharpcap screenshot.png (913.7 KiB) Viewed 3145 times
DSS (could just as well have been saved SharpCap frame) + a bit of PS (stretching/curves/camera raw filter - no brushes):
DSS M22b.png
DSS M22b.png (512.23 KiB) Viewed 3145 times
And, of course, this applies to all objects - I want to get more clarity, saturation, color separation, contrast, etc.

As you can see, "night and day" even though this comes from exactly the same source data - in fact, it's just the final image that is being post-processed to extract all the data.

Is this something I can do today with better configuration/settings of SharpCap Pro or is are additional post-processing features required?
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admin
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Re: Trying to get better view of results

#2

Post by admin »

Hi,

you should be able to significantly improve the display by manipulating the stretch, colour balance, saturation, etc in the 'Histogram' tab of the live stacking panel. Unfortunately I can't tell if you've tried this or not from your screenshots because you have collapsed the live stacking panel down to the bottom. See https://docs.sharpcap.co.uk/4.0/#Histogram%20Tab

cheers,

Robin
givoly
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Joined: Tue Aug 31, 2021 9:01 am

Re: Trying to get better view of results

#3

Post by givoly »

Robin, thanks for response. Yes, I have tried stretching on both histograms stack and display. This screenshot is the result after those stretches produced the best results I could get on screen… incidentally, in the second post processed image, after stretching levels, the filters I’ve done in photoshop were all in camera raw: dehaze, clarity, vibrancy, saturation, and a bit more curves, mostly.
I wanted to try to reconstruct this after the live session from the ascom-captured raw frames, but folder monitoring doesn’t seem to read raw/cr2 files. So I would need to convert all files from 40mb to 144mb tif files.

Any ideas for further boosting resulting image?
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Re: Trying to get better view of results

#4

Post by admin »

Hi,

there are some sharpening and noise reduction tools in the live stacking enhancements tab, but they will not have the same power as the ones you find in a dedicated application such as Photoshop (one reason is that they have to be relatively quick so that they can be applied in realtime to each image update, but also the goal of SharpCap isn't to do everything that Photoshop can - more to be able to do enough to make decent images easily achievable).

I still think there will be something to gain by adjusting the colour balance and saturation - you look like you have typical muddy yellow/green colours which come from the sensor sensitivity being strongest in the green - boost the red a bit and the blue more to get a whiter look and then try to up the saturation to bring out more colour.

cheers,

Robin
givoly
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Joined: Tue Aug 31, 2021 9:01 am

Re: Trying to get better view of results

#5

Post by givoly »

Thanks for the tips. I will try. When you say 'boost saturation', how do you mean? Also, is there a way to reprocess the raw .cr2 frames (my DSLR ASCOM saved these originals, but I don't see how to have SharpCap read them without converting them to TIFF, no longer raw...).
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Re: Trying to get better view of results

#6

Post by admin »

Hi,

the controls at the right hand side of the live stacking histogram allow you to adjust colour balance and saturation of the displayed image (note - this does not affect the actualy data in the stack, just the image displayed on screen and saved with 'save as seen'). See https://docs.sharpcap.co.uk/4.0/#Histogram%20Tab

Unfortunately reading CR2 files is not supported - you would need to convert to FITS, TIFF or PNG (PNG can be 16 bit, but not all software supports this - SharpCap does for both reading and writing).

cheers,

Robin
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