This newly acquired data set is an improvement on the earlier.
36 lights, plus bias, darks and lights. Preprocessing in Pixinsight, post processing in PI and StarTools, which I am still coming to grips with.
Cooled and modified DSLR, ISO400, 28 x 210 seconds, plus 8 x 210 seconds @ ISO800.
The advantage of cooling is the use of previously generated master frames. A set of ISO400 flats was all that was required.
Focus is close, but not perfect. A follow focus type arrangement should make the tiny adjustment required much easier. The difference between focus and out of focus using a mask is less than a hairs breadth and difficult to achieve accuracy using the lens focus ring.
Edit: added a jpeg for a quick look and the focus mask image, using a custom designed mask. On closer inspection focus is not perfect. the longer spikes are not evenly spaced top to bottom. In live view zoom it is hard to pick the difference.
http://astrobin.com/11350/?r=1803
