Hi all, I'm new to photography, I have a d3200 and want to upgrade soon to a d750, I want a very good full frame landscape lense, I was thinking about the tamron 15-30 vr 2.8 bus as I love long exposure photography and it doest have a filter thread it's back to the drawing board, my budget is about $1000, I really hope I can get a great landscape lense for that price. Any suggestions?