I recently had the opportunity to go out to Farpoint on 2-4-2021. I was excited to use the club’s Starlight Xpress SXV-M25C camera. The object I decided to image was the Rosette nebula. A nebula in Monoceros east of Orion. It is a HII region, a region with lots of hydrogen that gets ionized by nearby stars. This camera does not cut hydrogen alpha light as much as my Canon DSLR. Even though HII regions are not just hydrogen alpha light, I thought it could still be a good use of the camera.
I spent over an hour polar aligning my mount and focusing the camera with a 200mm lens with a UV/IR cut filter in front. I started guiding and exposing taking 35×240 second exposures for a total time of 2 hours and 18 minutes. I ended up packing up a bit early because of cloud cover, however I wish I waited 20 minutes before packing up because it was clear half way through putting everything away. A couple days alter I processed the image by combining the exposures to get the image you see at the top.
I’ve had quite the adventure with this camera. Originally I had an issue with it not working with INDI (my preferred software). I had to find the cause and summit a patch to the project (https://github.com/indilib/indi-3rdparty/pull/11). Also color was a issue, I ended up making a color sheet with construction paper to help me figure it out. I found out that for this camera model, INDI writes out the bayer matrix in a odd order. I wrote a script to reorder the bayer matrix so other processing tools could be used.
As for the hydrogen alpha, not sure if the image really benefits from the extra hydrogen alpha sensitivity, but this image is a lot better than previous attempts of the object, and I don’t think it hurt.
Any member of the club can use the camera at Farpoint Observatory. I hope this shows a little bit what it is capable of.
– StarSync Trackers SSTEQ-25 Forkmount
– Meade 8×50 finder used as guide scope
– QHY 5IIM camera for guide camera
– Starlight Xpress SXV-M25C for main imaging camera
– Asahi Pentax Super Takumar 200mm f/4 (set at f/5.6)
– 3d printed Bahtinov mask