Last night I had little hope for a reasonably good image of the Rho Ophiuchi region. Azimuth is only 13deg at maximum for this region from my location. It was visible only for one hour between a tree and our house. Plus there was a strong gusty wind and bad seeing. So it was basically hopeless.
I just took six images with my luminosity filter and five with the Halpha filter, 5 mins exposure each. After not seeing very much on each individual image I was tempted to throw them all away at dawn directly after the session.
However, today I went through the standard processing with Siril and found the stacked images not too bad. Thus I tried a little more processing:
- L and Halpha images were aligned and histogram calibration was performed
- Stars were removed from the Halpha image
- L and Halpha image were added with pixelmath (L + H/3)
- Standard Noise Reduction was applied
- Sirils Contrast-Limited Adaptive Histogram Equalization was applied with spectacular results for the dust patches
- Color Saturation was adjusted
- A Background Subtraction was performed based on the dark areas
I find the resulting image stuningly beautiful, especially taking into account that it has less than 1hour total imaging time and its not an LRGBH image, but only LH !
UPDATE 1: I had the opportunity to spent another hour observation time on the object in Halpha. It didnt improve the image a lot, still I include the image version as the new final image.
UPDATE 2: I moved the telescope to our balcony to south to add RGB data and more L and H data to the image. This was possible due to ASIAIRs new polar alignment algorithm which no longer requires any view to the north. Is this image with more than 6h observation time "better" than the first image with only L and Halpha data and just 1h observation time ? I am not sure, whats your opinion ?
Comments