What is causing this flare?

[Alan]

Gian, I'll run that experiment soon. Thanks.


I use B + W filters.

[Gian Luca]

B+W are excellent filter they should not give problem. On the other end is the lens had some problem you should have it again in the second picture. This should be even worse as the light is directly in the frame.


I think this was just unlucky and due to the angle + space between lens and filter, I also think that this will be very difficult to reproduce.