PieterVuylsteke
Well-known member
Hi,
My first post on this interesting forum. First of all thanks for the sharing of information that can be found here.
My problem is as follows :
- I took 80 photo's with a Nikon Z7 and 300mm f4 PF lens and ioptron skyguider pro.
- image calibration, debayer, subframeselector with the weights of lightvortex website, staralign, and then imageintegration.
- Normalisation : Average, Normalisation : Adaptive normalisation, FITS keyword SSWEIGHT.
- Pixel Rejection : Linear fit (or winsorized sigma clipping) and adaptive normalisation.
- in fact, the first time I did the stacking, I had a star align with another photo from another session that was turned 90 degrees. The colored zones were not present, but there was another less obious blue zone. I thought a reflection, but that is not possible as on this photo it is not present. So the artefact changes in function of the content of the photo. That was with a previous version of PI.
- The two zones are also visible in the high and low rejection photo's.
- If I do not use Adaptive Normalisation, the artefacts are not present.
-Afterwards I simply stretched with an STF and then a HT with the parameters from the STF. No other processes were done on this picture. Resized for publication in photoshop.
Windows 10
PixInsight version : 1.8.8-7
Seems something goes wrong with the algorithm ?
The blobs seem analogous to what can be seen in this older posting :
My first post on this interesting forum. First of all thanks for the sharing of information that can be found here.
My problem is as follows :
- I took 80 photo's with a Nikon Z7 and 300mm f4 PF lens and ioptron skyguider pro.
- image calibration, debayer, subframeselector with the weights of lightvortex website, staralign, and then imageintegration.
- Normalisation : Average, Normalisation : Adaptive normalisation, FITS keyword SSWEIGHT.
- Pixel Rejection : Linear fit (or winsorized sigma clipping) and adaptive normalisation.
- in fact, the first time I did the stacking, I had a star align with another photo from another session that was turned 90 degrees. The colored zones were not present, but there was another less obious blue zone. I thought a reflection, but that is not possible as on this photo it is not present. So the artefact changes in function of the content of the photo. That was with a previous version of PI.
- The two zones are also visible in the high and low rejection photo's.
- If I do not use Adaptive Normalisation, the artefacts are not present.
-Afterwards I simply stretched with an STF and then a HT with the parameters from the STF. No other processes were done on this picture. Resized for publication in photoshop.
Windows 10
PixInsight version : 1.8.8-7
Seems something goes wrong with the algorithm ?
The blobs seem analogous to what can be seen in this older posting :
Adaptive Normalization - Where is all the detail?
So I got a decent couple nights and got quite a few subs of M31, thinking I would build up enough data that I had a really wide, detailed shot. I also wanted to try Adaptive Normalization as I had a few frames in there with very high thin clouds, and it sounded like that might help. I...
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