The noise on the hill

Nikon D300. Lensbaby Velvet 56mm (84mm equiv.), t25 sec @ f/5.6, ISO 3200
Location: Colca Valley, Peru.
My intention was to produce a composite of the star trails with some 20 photographs, but I failed on the matter of the tripod. I thought that maybe photoshop would realign the pictures but it all turned into a mess when overlaping at the edit. It might also have affected to this respect the fact that the lensbaby velvet 56 has a strong focus fall off at the border of the image, I am not sure yet, before I’ll have to eliminate the first probable cause, the weak tripod (the one that I use with no issues for my lightweight X100T).
The noise produced by the D300 for long exposures could be discouraging but I decided to use it with creative purposes. First I turned the photograph into black and white and then increased the clarity until I got a very pronounced texture. I liked the schematic result between the tonal zones and the suggesting mixing of the real stars hot spots with the fake ones. LR and PS.