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Weird quality scores with Ha-OIII Extraction and failed Ha extraction
I have been shooting a mosaic of 6 panels of IC 1805 with an Optolong L-Enhance Filter over a period of time. I managed to create the mosaic with the Ha-OIII color algorithm. Then I wanted to separate in an Ha and an OIII image so I could merge them with a specific RGB palette. So I started to create 6 Ha panels and 6 OIII panels with the intent to create a single Ha Mosaic and a single OIII mosaic and then merge both images. Extracting the first 5 Ha and OIII panels went ok, but the 6th failed to create an Ha image. Then I went to have a look at the quality scores of the different extractions and noticed that the OIII quality scores were in line with Color quality scores, but that the Ha scores were almost opposite to the OIII and Color scores. I have created graphic of all three scores (great that we now have this information btw). Can anyone explain why the Ha data is behaving like this?
As a side note): my dew heater was no functioning properly., so when I came back in the morning there was dew on my lens. This may explain why the quality of the overall picture went down, but it only makes me curious why the Ha score then went up???
Hi Tom @tvanpeer,
Thank you very much for sharing this. I think I might know why this happens with the quality score, it has to do with data normalization. Can you check how the quality scores relate if you use another normalization method in 5) Normalize? Probably with additive, it will look more logical.
I would love to try the suggestion you mentioned, but the process already fails at registration, so before normalization.
Hi Tom @tvanpeer,
Oh, there was no mention in your initial post that even registration is not working? Did you enable the cosmic ray/noise reducer in 3) Analyse stars? Maybe that will solve it, APP might think that hot pixels/noise are stars and then registration will fail and the quality scores are not correct since stars are not detected properly. Set the noise reducer in 3) to a value of 10-16 and it should work. If it does not, please let me know.
This issue with locking on to noise instead of stars is on my list to fix.