SLR Magic Variable ND Filter 0.4-1.8 Mark II (77mm) 35mm Camera and it requires the Sony

and it requires the Sony E 16mm f2

Linhof 70mm slip-in filter

Hasselblad UV-Sky filter in B60 size

That's right: both eyes open

Whether or not you plan to use this camera (and we hope that you do)

SLR Magic Variable ND Filter 0.4-1.8 Mark II (77mm) 35mm Camera and it requires the SonyThis SLR Magic Variable ND Filter Mark II is specially designed to minimize the weird uneven vignetting that sometimes afflicts variable filters. How? Using "special glass and treatment." Not sure what that means, but it seems to do a pretty good job. ND range is from 0. 4 to 1. 8 (just over 1 stop to about 6). A bit bulky it's thick, and the outer thread is 86mm but this filter includes its own lens cap to make up for at least the last bit of that.