Neutral Density?

Inspired by recent blips from Tussock Tales and Danhortonszar I set out to experiment with my ND filter*.

Never really tried it properly, so this was going to be the day!
'Was' is the correct word in this sentence as all my images were either too light or too dark - specially in the center.

Obvious I need some guidance how to do this right... Anybody???

Thank God I had my iPhone as a back up and made this shot of the making... eh... failing off ;-)


*L.C.W. Fader ND MK II 67.0s [W-T]