Great shots Baz
I was imaging at a similar focal length to you this morning as well. I'm pleased to see you also picked up the faint green colour in the sky, particularly in that last one. I initially thought my camera's white balance was on the blip, but then I remember seeing a similar thing in one of Alex Cherneys videos
http://vimeo.com/28487411 Apparently caused by natural oxygen in the upper atmosphere. Someone else might know more about what causes this. I just take pictures