Boyd, I agree with you that thirty seconds is to long of an exposure and image blur will be the result. Your eight second exposure produced a pin point of light. This morning it is very obvious to my not so tired eyes. Tonight I will take a range of shots backing down from the thirty second exposure by five second increments to see where the sweet spot is for the 15mm lens. I have a faster 40mm pancake lens that I want to try. The sensitivity shouldn't be an issue, the F stop will remain the same. This time though, I will bring the my laptop with me to get a better idea to what the shorter exposures look like. The tiny LCD screen on the camera doesn't help at all with larger details.
I don't think I will return to the shore this evening, a quick trip to the Sourlands ridge means less windshield time.
I want to retake the road shot in the summer with the bright summer Milky Way intersecting the end of the road. Somehow I have to work around the ever changing traffic light at that location. I don't know if it will be as dark. Sandy knocked out the two marinas along this road which are normally bathed with orange and white security lights. Another issue is how to deal with the flying biting insects. If you know this strip of road, it is vicious and blood letting.
BTW- I appreciate bouncing ideas around with you. It has helped me to move away from the box I was comfortable in.