lower iso
The bottom was shot at F4, 126seconds, at iso 1600 - noted, due to the overwhelming comments on noise reduction - I'll go ahead and remove the noise. Of course I'll lose sharpness as a result, but my point is, it's actually a very low ISO for my typical night shots.
The top (sharp stars) was shot at iso3200, F1.4 for 8 seconds.
Superb!
Why do the stars appear this way? Are there two separate images of the stars? A high ISO image of the bright points at the terminus, and a low ISO image of the trails? Or am I imagining things?
Peter the method was essentially a composite. There is one shot of the foreground (see bottom camera settings above) and another for the sky (sharp stars)
The original intention was to simply take the sharp foreground using the Long Exposure, and blend it with the sky which needs to be at 8 seconds or less to not show star trails when shooting at 50mm. When I blended the two, I found it more interesting to actually include a little bit of the star trails.