I had spots on my D50 that I thought were on the lens due to them only showing up at F/8 - 22... then I realised it happened with EVERY lens I had at F/8-22 took a wet sensor clean to fix mine... it was... frightening to say the least.
Very nice shots of the halo, I particularly like the halo above the light house. Very artistic angle...
The moon had a lovely halo thursday night, shame I was at work without my camera