When I shoot people in open shade with fill flash and ebay triggers, often the brightness of the background is a problem because I'm limited to 1/250. I have a 2 stop ND for my 85mm, but can't decide whether to get a 1 or 2 stop for my 50mm f1.8. I'd prefer a 2 stop but I'm not sure if the nifty will focus reliably with it? I know the max aperture would still be less than f4, but anyone have any experience? Would I be any better off upgrading to a 50mm F1.4 plus a 2 stop?