Vierwaldstättersee / Lake Lucerne

I was away for the weekend in Luzern. Managed to get a few images done on Sunday morning. 

It's a long exposure shot using a 16 stop ND filter for just over 9 minutes. I still some trouble removing the slight purple haze caused by the filter, so any tips would be welcome.

Using such a long exposure is a great way of removing Pedalos, Paddle Boarders, swimmers and rowers falling out of their boats.