No diffo not, filter maybe though lol
Now that would be a possibility thinking about, as i was running a skylightb for the top 2 just after changing from a polar.
I hate having my lens open, even with the hood on. i did clean it to at some point after that i think, all the ones before are the same, and a couple after, but then there not lol
Asume it was a dirty filter, lucky dirt, or spoilt the pic?
Personal i quite like it.