I am trying to obtain this effect during nightly shots:
1) A first capture with short exposure, potentially with very high ISO, to capture the stars as points. I'll later clean the noise. 2) A second capture with low ISO and long exposure to capture the details of the scene. 3) Mix the long exposure and the stars together.
The problem that I face is the very strong contrast between the scene (second capture) and the sky (first capture). Photomatix's HDR does not work well, neither photoshop's one.
Manually, the problem is that selecting the sky from the sort exposure shot is tricky, especially between trees. The result is a failed picture where the merging line is very noticeable and unnatural.
What is your favorite workflow to achieve the result that I want?