Star Alignment on Lights Only Halpha, SII and OIII

Note: I'm not saying the registered HA frames are not registered - they definitely are registered. I'm saying that the HA integration is not an integration of the registered HA frames.
 
I don't know how I messed this up thanks again it looks better.

Do you know what would cause this? I circled these the two spots.

NGC2264.zoom2.jpg
 
I suspect that these are the integrated remnants of uncorrected hot pixels - to check look at this location in the unintegrated frames.
 
Would those be the reject frames?

I also noticed this error after channel combination. It did not cause the process to terminate maybe just a FYI?


ChannelCombination: Global context

Combining RGB channels: done

** Warning: Inconsistent Instrument:Filter:Name (FILTER keyword) value(s) - metadata not generated.

1.030 s
 
Tip: how to zoom in on the same location in another (aligned) frame (in case you haven't see this before). If you define a preview window zoomed in on the object in question in the source frame, then you can drag the preview tab to another (target) image, and a new preview will be defined at the same size / offset in the target frame.
 
sandconp said:
Would those be the reject frames?

I also noticed this error after channel combination. It did not cause the process to terminate maybe just a FYI?


ChannelCombination: Global context

Combining RGB channels: done

** Warning: Inconsistent Instrument:Filter:Name (FILTER keyword) value(s) - metadata not generated.

1.030 s
Click to expand...

ChannelCombination is trying to make one image from 3, and it's trying to preserve the metadata as best as possible. as you might expect, each input image has a different value for the fits keyword FILTER. since the new image is a 3-plane image, there's no one right FILTER attribute for it. so CC is telling you it couldn't come up with a FILTER keyword for the RGB image that made sense, and is not generating the FILTER fits keyword.

rob
 
sandconp said:
Would those be the reject frames?
Click to expand...
I'm not sure what you mean by "reject frames". If you mean the rejection map generated by ImageIntegration, then I would suggest that, with only two "real" frames to integrate you have no statistical basis for pixel rejection, so you should not enable pixel rejection.
For this particular artefact, three of the unregistered images have a hot pixel at (1967, 1850). When this pixel is interpolated (after registation), it is "spread out" into the "dot and ring" pattern.
 
yes with so few input frames you're going to have to rely on CosmeticCorrection to clean up those hot pixels before you go into StarAlignment...

rob
 
pfile said:
ChannelCombination is trying to make one image from 3, and it's trying to preserve the metadata as best as possible. as you might expect, each input image has a different value for the fits keyword FILTER. since the new image is a 3-plane image, there's no one right FILTER attribute for it. so CC is telling you it couldn't come up with a FILTER keyword for the RGB image that made sense, and is not generating the FILTER fits keyword.

rob
Click to expand...

that makes sense.
 
Running CosmeticCorrection on the raw images before alignment, with "use Auto detect" and both hot and cold pixels set to 2.0 sigma, followed by the same alignment, integration and channel combination as above, gives the right hand image (compared with the previous processing in the left hand image). Note that the "hot pixel" artefacts are gone, and the vertical band is reduced.
1611613526529.png
 
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