Hi Paul
Thanks for the complements. The images were captured in RAW mode (a native Pentax mode) and then I converted them to 8 bit tif's with the proprietary Pentax Photo Lab software. I used ImagePlus, (see
http://www.mlunsold.com/ ), to align and then combine the images, followed by a default DDP in ImagePlus.
The stacking and DDP really makes this image, when compared to any one of the original, unprocessed 30 sec exposures, which look quite dull and washed out in comparison.
The sensitivity was ISO1600, manual focus, 30 sec exposures with the Pentax taking automatic, in-camera dark frames for each exposure. I forgot to take flat fields, but I don't think I needed them in the end.
Cheers
Dennis