Originally posted by loco Thank you! At web size you would not notice it, but I have tried the K-1 with the 14mm at several exposures and some small amount of trailing is evident at 20s, especially at the edges of the frame. And you are right, the Astrotracer might not have worked. I hadn't thought it through.
I used it once attempting to shoot the Milky Way and the stars came out sharp enough but there were a few clouds about and they took on an odd rippled look. It's certainly a useful feature, but it's not a magic bullet. It does better with stars at high angles and not so well as you get closer to the horizon. With wide angle shots you'll often get sharp stars in the upper frame while you get trails near the horizon.
It's more work and I haven't mastered it yet, but I've seen the best results with multiple short exposures and stacking software. Deep Sky Stacker is very popular but it's not easy to use. StarStax gets spectacular results but it won't accept raw files so you have to either use jpegs out of the camera or export to tiff. There are others but I'm not serious enough about it to pay for them.
The absolute best tool for wide angle night sky photography is an inky black dark sky. The place I usually go is about 25 miles out and it still suffers some from the urban light of Phoenix. I probably need to go another 25 miles to get truly dark skies.