Giants Causeway

Our lovely daughters bought us a Groupon for an overnight with dinner in Dungiven Castle.  This has changed hands in recent months and it is a lovely boutique hotel though offially it's a 4 star B&B as you have to have 16 rooms to qualify as a hotel in Ireland.  Roy our host was very nice and we had a very good meal.  On the way up we were uncertain about the weather it looked like it could rain at any moment.  We arrived around lunch time, had lunch and afterwards decided to take our chaces and head to the Giats Causeway, and we were very fortunate as it was a lovely sunny afternoon.  Sharon and I had a grand couple of hours taking photos.  Sharon took my D700 and I used the D800.

The above is a long exposure using a B&W 10 stop ND filter. However, I have a problem with the image, if you run the mouse over the image you will see the original colour image and see the problem. The purple colouring in the middle third of the image. If anyone has any ideas on what this could be I would appreciate the help. The technical details are: Nikon D800, Nikkor 16.0-35.0 mm f/4.0, taken at 25.0 secs at f/20. I used the B+W 77mm 110M Multi Coated +10 Stop Neutral Density Filter - F-PRO Mount

I have a couple of ideas I want to try out and I want to check results between the D700 & D800 using the same lens, but in the mean time any ideas on what the problem could be is much appreciated.

 

Addendum:

I forgot to mention that the tide was coming in and a huge way broke over the Causeway soaking me up to the knees but worse still, it splashed my lovely new D800 and shiney new 3 Legged Thing tripod.  I quickly turned off my camera and started to dry it off with Sharons silk scarf.  What a scare, but all appears to be fine now, everything works.  Though on Sunday night I decided to take a closer look at my tripod (Brian), and I could see it was still wet and had some salt deposits.  Fortunately, you can take the whole thing apart, which I did, over the next couple of hours and cleaned it, dried it and oiled it again.  Whew scarey!!