Testing out some very long exposures on the D600 tonight, using my mom-in-law's backyard as a subject. This one was 30 minutes, which appears to be the longest you can go - I'll have to check into why it can't go longer...
This particular photo seems to have a lot of banding in the sky, but I'm a bit limited with only having an iPad. I'll fix it when I get back to my home computer with Lightroom. I hope.