Haze around edges?

[1hoax]

Hey there, have done half a dozen or so flights and all images and videos have been crystal. For some reason on my last flight (no filter and no editing) there seems to be a haze around edges. Any ideas why?

 

[4wd]

In that frame you do have rather tricky lighting with brightness on the water and light fog.
A scene like that would be troublesome to take a good photo with full manual still camera.
The vignette effect is sometimes quite pleasing, and can be added with more sophisticated editing software.
It's a useful way to get some detail back into a washed out sky.