Date: 1/5/2011
Location: San Bruno, CA
Telescope: C9.25 on NJP-Z mount
Camera: Qhy8 with CLS CCD Filter
16 exposures of 2 minutes at f/d 6.3.
Processing: Maxim DL5, Photoshop CS4, Astraimage Wavelet filter
The Eskimo planetary nebula has a fairly small angular size: about 48″, comparable with the apparent size of Jupiter.
At focal plane, the scale was about 1.15″ by pixel when taking this image.
Collimation is critical at this focal length – and I made sure the SCT was well collimated.
Given its high surface brightness, shooting NGC 2392 benefits from many short exposures to get the best of seeing conditions, and processing techniques such as sharpening or wavelet filtering.
For this pictures, I tried out my new Losmandy dovetail plate on which the guidescope (Takahashi fs60c) is attached.
I had trouble with tube flexture in the past with other systems to attach the guide scope to my c9.25, but with this great dovetail plate, the guide scope is now coupled to the C9.25 OTA in a very rigid way.
Astrophotography in Urban Environment 