I had my first imaging session of the new season on the array last night using the 200mm lenses and the ASI 2600MC Pro CMOS cameras.
The bright star Sadr sits in the centre and it also sits with the Butterfly nebula. Bottom right is the crescent nebula, and above Sadr, the blue region, is NGC6914 a reflection nebula (the only patch of blue in a sea of red as I call it). And that reflection nebula caused some issues.
Last night’s data was 12 x 20-minute subs (4-hours) with the ASI 2600MC Pro CMOS cameras and an Optolong L-Enhance filter. The Optolong filter is a superb addition to a one-shot colour (OSC) camera as it provides narrowband H-alpha AND OIII filtration. However, with this image this comes at a cost, as a reflection nebula is broadband blue, so the filter effectively removes the nebula from the image. What to do?
Fortunately I had previously taken unfiltered data of the region using an SX M26C OSC CCD, and in that image the blue reflection nebula was clearly seen. So I added the 3 hours and 20-minutes of earlier unfiltered data to last night’s 4 hours of filtered data, to get the result in the image.
I hope you like it.