The images are shot with my nikond5500, using a samyang 14mm F2.8 lens.
the foreground images are one single image, shot with 5min eksposure at F8. The sky exposures are 2min subs for the tree and 1min subs for the bog (the moon was up).
After taking my foreground, and when i'm sure that it's what i want, i start shooting the sky from the same position. As for the old tree, i took a reference shot at ISO 3200 (for the galaxy) and then i moved my setup in front of the tree and matched the reference shot as best i could. Then i took a 20min series of subs, which where then combined in PS.
When combining the foreground and sky, i mask out all tracking errors of the sky in the foreground image, then i line up the reference shot and then i place the sky image behind that. I then remove the reference shot and adjust final positioning, making sure that any tracking error of the sky image' foreground doesn't show.
If i can't move my camera in front of the foreground, i shot the sky just after i shoot the foreground. I don't shoot the sky more than 20min total, as the tracking error becomes too much then (this of course depends on how far away objects in the foreground are).
If the scene is very complex, i shoot the sky as quickly as possible and with as high ISO as can be accepted.
I usually try to stack the sky exposure with PS, as i find PS does a better job for this kind of images than DSS.
Edited by jakob1234, 16 May 2019 - 02:13 PM.