Hi, I'm a new forum member.
I've tried some star photography over the past few months and am getting what I'd call a "flare" on some of the brighter star images at the periphery of my image. An example is here:https://www.flickr.com/photos/mark_mathu/14703465134/sizes/o/
This exposure was ƒ/3.8, 38.9 mm, 30 seconds, ISO 250.
You can see the flare on some of the stars on the right side of the image – they look almost like a badminton birdie.
I'm using an AF Nikkor 28-70mm f/3.5-4.5 which I bought new about 20+ years ago with a Nikon D7000 body. I almost always keeps a Teffen Haze-1 filter over the lens which would be from the same vintage as the lens... so although I didn't keep specific notes I'm pretty sure it's been on the lens when I've taken the photos.
Any suggestions on how to reduce the problem? Is it just the old filter I'm using? Has the lens coating gone to hell? Is this just a shortcoming of that particular lens? I've never noticed this before, but then on the other hand I've not really tried much photography like this prior to getting my D7000.