Saturday, February 16, 2013

First image with new setup: M44

As my very first image, I chose M44 - I figured that an open cluster is a good start object. Because I still couldn't figure out how to control the filter wheel from TheSkyX, I had to move it between series manually :-(

I took LRGB images. All images have a lot of noise - I wonder if it is because of our light pollution here. And I needed new darks, bias, flats and dark flats. I ended up with:
10 Luminescence 60 sec
5 RGB 240 sec
20 Darks
20 Flats
20 Dark Flats
20 Bias

Taking the Flats turned out to be quite the challenge. The flat panel that I use is too bright for the color filters and I had to use such a short exposure, that the vignetting did not come out. I ended up waiting for dawn and took them then. Also, they had lots and lots of artifacts:

But on further inspection (and after taking a second set of flats and processing them) it turned out that my scope (the camera and the corrector plate) are really this dirty...

I also used this as an opportunity to try out CCDStack. It's much more manual then Deep Sky Stacker, but I think it's worth the effort. I'll have a month or so before I have to decide if I want to buy it.

After a day of learning and playing, I finally had my first LRGB combined image. I did some basic processing in Photoshop and ended up with this:

Overall, I'm pretty happy with this, the star colors are good (but not too saturated). The only problem I had was that the background was very noisy. If you zoom in, you can see that the stars have a pretty strong halo, but that it then drops off. I wish I could have done this better.

This was also the first time, that I used the OAG instead of the guidescope. And I had the same drift during guiding that I had before. The good news is, that the guidescope seems to be OK. The not so good news is that there is this drift. I hope that this will improve when I hypertune my mount (everything arrived yesterday!) Unfortunately, I won't have time to do it this weekend and next weekend.