Dear fellow astronomers,
On my lazy journey of OSC astrophotographer, I took my chance and bought the new Askar Colour Magic Sii+Oiii C2 filter, in the hope of adding some Sii signal to my images. I know that the perspective are limited and many poeple advised me that, at this point, I should consider moving to mono. I think that at 93$, adding Sii to all these image was a nice project, allowing to postpone the switch to mono by one year and to continue making the most of my OSC gears.
Well, here are some initial results. I tried with little success to integrate my new Sii layer extracted from the OSC data using SIRIL, just like I extract the Ha. Unsatisfied with the result when adding it to my NGC 281, and without much expercience with Sii layers, I ran a comparison between the two Oiii layers. Below, you find a crope of 15300s of Oiii using a l-ultimate on the left. On the right, you find 12000s of Oiii, same very well known region of NGC 281, using the Askar C2. Both images are captured using a TS UNC 200/800 newtonian and an ASI294MC pro. Subs are 300s long in both cases. I just croped the stacks and applied an autostretch in Pixinsight.
The comparison is clear. The C2 delivers very inferior results I am afraid. Note that running FWHM and exentricity tests in Pixinsight, the image capured using the C2 should be slightly better in sharpness.
Here are the Sii and the Oiii side by side, where one can immediately see that the Sii suffers from the same problems...
It is clear that the band pass are not comparable. Whereas the l-ultimate has 3nm, making it a high-end filter, the C2 has OIII：35nm±5nm/SⅡ：15nm±3nm
I have however difficulty to understand how the difference in spec could account for such a different result.
I wanted to share this, in case anyone is tempted. Any thought or hint to improve outcome is much appreciated.
Clear skies !
On my lazy journey of OSC astrophotographer, I took my chance and bought the new Askar Colour Magic Sii+Oiii C2 filter, in the hope of adding some Sii signal to my images. I know that the perspective are limited and many poeple advised me that, at this point, I should consider moving to mono. I think that at 93$, adding Sii to all these image was a nice project, allowing to postpone the switch to mono by one year and to continue making the most of my OSC gears.
Well, here are some initial results. I tried with little success to integrate my new Sii layer extracted from the OSC data using SIRIL, just like I extract the Ha. Unsatisfied with the result when adding it to my NGC 281, and without much expercience with Sii layers, I ran a comparison between the two Oiii layers. Below, you find a crope of 15300s of Oiii using a l-ultimate on the left. On the right, you find 12000s of Oiii, same very well known region of NGC 281, using the Askar C2. Both images are captured using a TS UNC 200/800 newtonian and an ASI294MC pro. Subs are 300s long in both cases. I just croped the stacks and applied an autostretch in Pixinsight.
The comparison is clear. The C2 delivers very inferior results I am afraid. Note that running FWHM and exentricity tests in Pixinsight, the image capured using the C2 should be slightly better in sharpness.
Here are the Sii and the Oiii side by side, where one can immediately see that the Sii suffers from the same problems...
It is clear that the band pass are not comparable. Whereas the l-ultimate has 3nm, making it a high-end filter, the C2 has OIII：35nm±5nm/SⅡ：15nm±3nm
I have however difficulty to understand how the difference in spec could account for such a different result.
I wanted to share this, in case anyone is tempted. Any thought or hint to improve outcome is much appreciated.
Clear skies !
