I am looking at getting a Variable ND filter for my kit ( I know a set of ND's is better, but it seems like it would be out of my budget. I also like the ability to use variable ND for video purposes).
My question is two fold:
1. Because it is a wide angle lens, do I need to get a "slim" version and is it out of the question using a 77 with a step up ring to the 72mm filter size of the lens?
2. Which Variable ND's, if any have you had success with? My budget is about 150 for the filter.