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Odd Nikon Concentric Ring Question

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#1 nhmorgan79

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Posted 25 February 2024 - 01:48 PM

I currently use an ASI2600mm with a nikon 500mm f4 lens for my imaging rig. I own a luminance filter and SHO filters for it. Before I invest in RGB filters though, I have a z8 on hand that I can easily attach to the lens as well. Before I invest in RGB filters, I'm wondering if using the z8 for RGB then combining with the luminance data from the ZWO camera will address the concentric ring issue and allow me to collect RGB efficiently with the z8.  In theory this should address the issue of colored concentric rings from the nikon camera on heavy stretches, no?



#2 sharkmelley

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Posted 25 February 2024 - 06:54 PM

I don't have any evidence on whether or not the Z8 has the same concentric coloured rings problem as other Z-series cameras and many Nikon DSLR cameras.  However, if anyone has a Z8 then I'd love to see a set of raw files taken according to my test protocol described here.

 

For Nikon cameras that do have the concentric ring problem, the rings are embedded separately in the raw data of the red and blue colour channels, so combining the RGB data with unadulterated luminance data will not address the coloured concentric ring issue.

 

Mark



#3 nhmorgan79

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Posted 26 February 2024 - 01:24 PM

I don't have any evidence on whether or not the Z8 has the same concentric coloured rings problem as other Z-series cameras and many Nikon DSLR cameras.  However, if anyone has a Z8 then I'd love to see a set of raw files taken according to my test protocol described here.

 

For Nikon cameras that do have the concentric ring problem, the rings are embedded separately in the raw data of the red and blue colour channels, so combining the RGB data with unadulterated luminance data will not address the coloured concentric ring issue.

 

Mark

I looked at the protocol, but other than taking the shots I don't know how to do that kind of processing. If I uploaded some raws to dropbox, what would you need? The series of flats and a bias (or multiple) files?



#4 sharkmelley

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Posted 26 February 2024 - 02:03 PM

I looked at the protocol, but other than taking the shots I don't know how to do that kind of processing. If I uploaded some raws to dropbox, what would you need? The series of flats and a bias (or multiple) files?

I just need the raw flats.  I'm very happy to perform the analysis.




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