Nov 23, 2006
After a nice T-day at Karl's, the skies were so crystal clear following a cold front that I had to do some astrophotography. I had with me the 8" f/4 LXD75 reflector and ST2000XCM. Trouble with the battery power, and by the time I got set up my planned target - the Veil Nebula - was too low. I settled for IC 1396 complex, near Mu Cephei, I spent valuable time trying to compose this faint and unfamiliar subject and it was now getting pretty low too. Add in bad post-cold front seeing, low altitude, and the dodgey rack/pinion focuser / camera connection leading to strong coma and poor focus... and the results aren't great, but it'll help me plan my next attempt. I decided to hope the same focus and calibration would work for the nearby planetary nebula NGC 7139. A single shot of 5 minutes and I was pretty cold and ready for sleep.
IC 1396 in Cepheus. 9x5min stack (Registax3), and post-processed in Photoshop CS2: Curves, AstroTools actions - 5x 'make stars smaller', 'enhance DSO and reduce stars', brightness, contrast. No cropping. This is a small part of this 3 degree wide nebula - it is the region closest to Mu Cephei. The red H-alpha emission on the surface of the dark nebula on the left is on the far right of this exquisite image from the web. |
NGC 7139 in Cepheus. Single 5min experimental shot. This tiny 80" planetary nebula is magnitude 13.3 and nearly lost in the 90' field of view. It required a heck of a lot of yanking to pull it out of the noise. Photoshop CS2 + AstroTools actions: 5x 'make stars smaller',contrast, levels, magnetic lasso around nebula then gaussian blurred, and cropped severely. The altitude was about 25 degrees. Clearly, it requires much more time on a longer focal length setup. |