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Old 04-12-2016, 11:22 AM
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Spookyer (Brett)
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Suggestions with Processing NGC7424

Hi all, I have used about 10hrs of data on this target. I am using PI. I processed the Lum and the RGB. My Lum seems reasonable after integration, DBE, Atrous Wavelets and stretching. My RGB image however appears blotchy to me even after Background neutralisation, Colour Cal, Atrous Wavelets and Multiscale Linear Transform. I am not sure why it still looks so noisy compared to the Lum image. Any ideas to take this forward?
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Old 04-12-2016, 01:17 PM
brisen (Brian)
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Brett

Have you tried the SCNR process? I am still learning to use PI but I just quickly ran the process on the jpg version and it made some difference to the overall image.

The link here http://www.lightvortexastronomy.com/....html#Section3 outlines the SCNR process - it is in after colour calibration.

Brian
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Old 04-12-2016, 03:38 PM
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Brett,

I would hit that with ACDNR. Use a lightness mask, a small amount of Lightness nr and heavier on the Chrominance. You'll probably lose some colour, so apply a clipped luminance mask and boost the saturation afterwards.

With a dim target like that it's not unusual to have a lot of noise in the colour data. You can get away with pretty heavy noise reduction if you have separate luminance.

Cheers,
Rick.
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Old 04-12-2016, 04:52 PM
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Thanks Brian and Rick. I will give it a go.
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Old 08-12-2016, 08:48 AM
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the RGB looks OK to me. you do not need much colour info where the image is nearly black and you have nice colour in the brighter bits. I would give an LRGB a try with what you have. If it comes out too noisy, maybe ACDNR like others have suggested and then do a DBE, probably best with a subtract of the background. You could do those two operations on either the RGB image or the final LRGB image (deselect luminance and select only colour in ACDNR). The luminance image seems to have some structure remaining in the background, so, if you do not apply DBE to the LRGB image, it would probably be a good idea to use it on the luminance anyway, to flatten that out a bit.

It looks like it will be a really good image of a difficult object.
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