Montana De Oro

D800, Nikkor 17-35 2.8, 1/60, f8.0, ISO 200

D800, Nikkor 17-35 2.8, 1/30, f11, ISO 200

D800, Nikkor 17-35 2.8, 5 sec, f22, ISO 100, Hitech 0.9 ND Hard Grad, Heliopan Polarizer

D800, Nikkor 17-35 2.8, 4 sec, f16, ISO 100, B&W Polarizer

D800, Nikkor 17-35 2.8, 4 sec, f13, ISO 100, B&W Polarizer

D800, Nikkor 17-35 2.8, 4 sec, f13, ISO 100, B&W Polarizer

D800, Nikkor 17-35 2.8, 4 sec, f13, ISO 100, B&W Polarizer

D800, Nikkor 17-35 2.8, 20 sec, f10, ISO 250, B&W Polarizer

D800, Nikkor 17-35 2.8, f7.1, ISO 200

D800, Nikkor 17-35 2.8, 180 sec, f8, ISO 1600

Lee Big Stopper and magenta casts, infrared leaks

Magenta color blobs and light leaks

If you find yourself as I did, shelling out around $200 for a Lee Big Stopper ND filter and subsequently suffer enormous disappointment when all of your attempts at long exposures result in shots with amorphous magenta/pink blotches that are near impossible to color correct, just do what I didn't do and relax! There's a perfectly reasonable explanation!
Those pink/magenta blobs are caused by infrared light. It's common on some lesser quality filters of which I cannot attest to, but the reason you and I paid big bucks for the Lee brand was specifically for the lack of color casts.
In fact, Lee Big Stopper are designed to block IR light from getting through the lens.  That means, if you are suffering from the blobs, then light is getting onto the sensor from somewhere else.  The culprit on my photos was the viewfinder window.  Once I closed it, I never had any more color casts.  Some people have experienced light leakage from the focus window on the lens, so if you still have IR leaks after shutting the viewfinder, maybe try some gaffers tape over that area.

Nikon D800 17-35 2.8 iSO 100 180 sec. f8 with Lee Big Stopper