A number of weeks ago I stumbled upon a game changing piece of freeware, GraXpert. GraXpert's algorithm analyzes your deep sky image distinguishing stars and nebulosity from back ground sky and generates a background that eliminates gradients and reduces light pollution. A standalone app GraXpert is easy to use while offering settings that allow you to tweak the algorithm for better results. Prior to downloading this awesome piece of free software dealing with gradients, inherent to my ASI294MC Pro was a bit tedious. With GraXpert you just load the stretched image*, create the grid, calculate the back ground and save the processed image. That's it. You can adjust the sensitivity of the grid creating algorithm to background intensity and you can move, add or delete grid points to distinguish nebulosity from the background. Aside from reducing my workload the colors in my images have improved. Some recent images follow. Thor's Helmet nebula was actually imaged from my 3rd floor balcony in my heavily light polluted south of Boston suburban skies with 120 15s sub exposures.
*Stretching the histogram in Paintshop Pro seems preferable to the GraXpert stretching routine which seems to throw away black side data.
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| Comet C2022E3 ZTF (2/15/2023) |
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| Comet C/2022E3 ZTF (2/8/2023) |
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| Comet C2022E3 ZTF (1/30/2023) |
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| Comet C/2022E3 ZTF (1/27/2023) |
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| IC443, Sharpless 248, Jellyfish Nebula--Supernova Remnant. |
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| M42 Orion Nebula |
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| M48 --Open Cluster |
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| Flame Nebula (NGC2024) , NGC2023, Horsehead Nebula(B33) |
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| NGC2264 |
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| NGC2353 Open Cluster |
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| NGC2359 (Thor's Helmet Nebula) |
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| M46(NGC2437) Open Cluster + Planetary Nebula NGC2437 |
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| NGC2232 Open Cluster |
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| Messier 50 Open Cluster |
