question about coma with star images



The star trails were actually over Yellowstone Lake, and then an early am shot in Teton National Park.

Hi, I'm interested in moving from star trails to stars and interval shooting and time lapse photography. I've got a 14-24 2.8 and a 24 1.4. I'll be heading to Lost Maples State Park in the Texas Hill country in January for some night shots. Normally I shoot iso 800, f4, 25 second exposure at 30 sec intervals with my Nikon D4. If I shot at f 1.4 or f2 I could  shoot with just 3 or 6 second exposure, but I don't see that that would help, or I could come down to iso 100, however iso 800 on the D4 is just fine, and shooting at f 1.4 or 2 I am concerned about coma in the 24  f 1.4  lens.

Any insight, advice would be extremely appreciated.  Thanks, Steve