Since moving to NYC, camera size has become top of mind because many times the gear goes in a bag on my shoulder or my back. When the Black Magic Pocket Cinema camera became available for 50% less than normal, I couldn’t be happier.
Sweet, small and high quality, the BMPC can go anywhere. The first place I took it was to the street for a parade. Lot’s of them in NYC, and they last for hours so you get a lot of time to capture.
(Small note, these cameras run through batteries, so get a bunch)
Now, the camera was small but the daylight was large and changeable. Using my Nikon lenses, I needed an ND like crazy.
I didn’t want to just stop down the lens. That was not the kind of shooting choice I wanted to make.
The I found this: Fotodiox Vizelex ND Throttle Lens Mount Adapter

With a solid fit, and a 10-Stop variable ND built into a smooth action ring, this is what I had been looking for. It’s the smooth variable part that was the winner. Being able to adjust the ND as needed, fast, is key.
Like most adapters, all of your auto anything operations of the lens were disabled, and there were no click stops for the f/stops, there is another ring to set your aperture, using 6 main markers. They are both fluid adjustments, Perfect for video.
Would I prefer a click-stop, aperture control? Perhaps for stills if shooting on the fly, but this unit did the job I was looking for @ a $100 price point.
There are a few other choices out on the market, but one in particular will always be in the conversation:

I will tell you, if you use the Metabones Nikon G Mount Lens to Micro Four Thirds Lens Mount Adapter version, at about $140, you should know that the fit is so tight, you may think you are damaging the lens mount. Don’t worry, you are not.
It does feel like the adapter is part of the lens, but there is no speed in the field, changing lens>adapter combos.
It does have a tripod mount, so using the larger lens on a small body, may seem like you get a stress reliever.

Overall, use a prime on this camera, or a smaller footprint lens, than a fast DSLR zoom. Better balance.

Yes, I’d recco the Fotodiox Vizelex ND Throttle, for the Black Magic Pocket Cinema. Lots of features for a good price, and the ND throttle will do you right.