Posted in Astrophoto Log on September 12th, 2008 by Northwest Astro
Ring Nebula
Took the scope out again last night, and decided to try imaging using my 0.5 reducer on M13 and M57. Unfortunately, I picked the wrong order, and so things were not as fruitful as I expected. I started on M57 before trying to image M13, and so M13 was entering the trees by the time I got to it. The end result is that I might as well have been imaging without the reducer at all. It was a total bust, and the colors were off, possibly from stray light off the treetops.
M57 turned out a bit better, but now I fully realize just how much light comes out of these nebula along the hydrogen emission lines. With the stock IR filter on the sensor, it blocked most of the red color, and no amount of post-processing could get it back.
This was also my first night seriously trying to use dark frames, and I think so far the dark frames have been doing what they need to do and reduce noise. Also, I realize this particular focal reducer is not what I want to be using. It exaggerates the curved field to the point where there is a very small area to image with. I should probably sell the 0.5 reducer and get a 0.63 reducer/corrector instead. Although I might keep the reducer for visual observing, as the extreme curvature isn’t as noticeable there, and the views are still rather impressive.
