When I get frustrated at my slow progress, it is always good to slow down and remind myself that the main reason I started this WordPress blog was to document that very progress. I more or less had written off this Messier 45 short integration for a laundry list of reasons, but my friend, Dave, reminded me that I could always go back and try to reprocess the data for a better result. I might not spend anymore time on this particular set of uncalibrated subs, but I think I got most of the visual ring out of the frame (pervasive artifact I’m dealing with at the moment) and you can make out what the target is supposed to be even if I lost a lot of the nifty nebulosity around the brightest stars.
The Pleiades, or Seven Sisters (Messier 45), is an open star cluster in the constellation of Taurus. Its nine brightest stars are made up of the sisters Sterope, Merope, Electra, Maia, Taygeta, Celaeno, and Alcyone, along with their parents Atlas and Pleione.
I forgot to mention in my last post that the night was cut short by smoke. I don’t know where the fire was or how large it was, but it devastated the seeing with atmospheric particulate. I had to cut the evening short due to this, but tried to get Messier 33, the Triangulum Galaxy, before it got too bad. I also took some subs of M45, but this weird optical issue made the Pleiades shots unusable. That will be great target to shoot again another time. The noise/vignette one-two punch strikes again! I am going to get this sorted. Seriously.
It has been nearly 3 months since my last imaging session. It feels weird to even type that, but it’s true. When you live in a red to white zone and don’t have any narrowband imaging capability, the nights of opportunity cycle with the moon phase and the cooperative (or not) weather. Between that and travel, I have successfully missed the last few decent windows of dark sky… and it shows.
When I first started reading about what steps I needed to take to venture into this hobby, it was last fall at the onset of winter. The targets fresh in my mind, from my vantage in North America, were Messier 31 – The Andromeda Galaxy and Messier 42 – The Great Nebula in Orion. By the time I actually got around to pulling the trigger on the purchase of an equatorial mount, they were gone for the season. I went out last night to the HAAS dark site and set up for what I thought was going to be an awesome and long night of clear skies and catching up on my learning process. We are just beginning to see the winter targets come back around, so I had to take a stab at our nearest galactic neighbor. I’m still very new at astrophotography and learning a lot every time I get out and image, but even with the little experience I have to date, I could tell I was really rusty getting started last night.
There are a few major issues I am trying to understand and work through with my equipment and process. The two largest ones at this point are the tremendous about of vignetting I get shooting a full frame 35mm sensor through my refractor and 1.25″ filter wheel prime focus set-up. I lose almost half the image (at the edges) due to loss of light. The other, and equally annoying, problem I have is noise. The images are so very noisy. Even with darks, I can’t seem to get a creamy smooth look and feel to my backgrounds. I’m sure some of this is my post-processing Fu, but a lot of it is shooting with an uncooled CMOS that wasn’t designed to be used for multi-minute exposures. Almost everything that I really want to shoot is hanging in the sky begging to go deep. Deep exposures are just something that is a tiny bit beyond my reach at the moment without sprinkling the salt and pepper all over my images. I seem to be doing a fair job at that already.