Two days ago I started a thread showing some of the more-or-less "raw" or lightly processed images that I had taken with the ZWO ASI178MM-Cool camera (see below for that link) and here I'm going to post some of the images that have gotten more processing. I don't want to post these images in the "raw" thread because I've done some processing that has modified the images to the point where they may or may not be representative of how this camera will perform (given that the images shown below may be better or worse than what the camera can really provide -- some artistic license has been applied to the following images -- noise reduction and artifact hiding to name just two).
Here is the link to the "raw" thread:
Anyway, below is a processed sample of the Eskimo Nebula that was done in red light using 458 subs that were each exposed for 4 seconds (total integration time just over 30 minutes). This sample was also drizzled at 2X to increase the image size and then reduced to a final scale of 0.6 arc seconds per pixel. The linear image on the 2X drizzle had a measured median FWHM of 1.84 arc seconds (or three pixels at the final reproduction scale).
The imaging scope was a Tele Vue NP127is with a 0.8X reducer producing an e.f.l. of 528mm at f/4.2. There was no guiding used during the capture, so this is an example of the so-called lucky imaging technique for DSOs. There doesn't seem to be a great amount of red light in the Eskimo Nebula (at least in comparison to the blue/green region), so I think I over stretched this image somewhat to try and gain more detail in the nebula itself. I'm working on an RGB version which I hope will look better than this single channel result.
Note, for some reason the JPEG compression is clipping the background in this image, I don't know if it is the JPEG or just the conversion to 8 bits or the change in the color space (or all three).
Lastly, this was taken with the camera's thermal regulation turned OFF (i.e. no cooling). The sensor temperature was reported to be around 47F with an ambient air temperature in the mid-30s.
Edited by james7ca, 11 January 2016 - 06:50 PM.