ImPPG Brightness Normalization

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Jordan Konisky
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ImPPG Brightness Normalization

Post by Jordan Konisky »

Hello everyone,

Just wondering what settings folks use for the ImPPG brightness normalization setting for WL, Ha and CaK imaging. Or do you not use this feature at all?

Jordan


Jordan -
SkyWatcher ED100 Refractor with Diamond Steeltrack Crawford Focuser
Celestron CG4 Equatorial Mount
Daystar Quark H-Alpha Chromosphere
Lunt CaK B1800 Filter Module
Lunt White Light Solar Wedge
ZWO ASI174MM, ZWOASI1600MM Cameras
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Re: ImPPG Brightness Normalization

Post by GreatAttractor »

Hi Jordan,

I've added it to aid batch processing time lapses where the image brightness was slowly varying during capture, e.g. due to passing clouds, or just a sunset/sunrise as in this long lunar animation. (If you don't use batch processing, you can achieve the same normalization effect simply via tone curve adjustment.)

If you use it, I recommend setting the normalization range to 10%-90% or 20%-80%, as any subsequent sharpening usually expands the histogram.

Note that it won't work too well if the target's intrinsic brightness also changes, e.g. if a flare starts in an AR.


My software:
Stackistry — an open-source cross-platform image stacker
ImPPG — stack post-processing and animation alignment
My images

SW Mak-Cass 127, ATM Hα scopes (90 mm, 200 mm), Lunt LS50THa, ATM SSM, ATM Newt 300/1500 mm, PGR Chameleon 3 mono (ICX445)
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Jordan Konisky
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Re: ImPPG Brightness Normalization

Post by Jordan Konisky »

Thank you. Very helpful.

Jordan


Jordan -
SkyWatcher ED100 Refractor with Diamond Steeltrack Crawford Focuser
Celestron CG4 Equatorial Mount
Daystar Quark H-Alpha Chromosphere
Lunt CaK B1800 Filter Module
Lunt White Light Solar Wedge
ZWO ASI174MM, ZWOASI1600MM Cameras
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