This is a Nikon B4-mount ENG lens.

While this may be an "SD" lens, I put it head to head against my Micro-4/3 (M43) still photography glass and this lens more than holds it's own.

This is because the M43 lenses are corrected in camera.

This Nikon is just purely great.

You can shoot HD with this lens.

I'm already shooting 4K with this lens on my Panasonic GH4 in full Digital Cinema mode and there's no vignetting.

If you use the full M43 sensor (for HD) then you see a little vignetting in the corners. But the 4K modes use a slightly smaller crop area and this removes any vignetting. The same can be said for the Blackmagic Design Pocket Cinema Camera's Super 16mm sized sensor area. You would have no vignetting there either.

This lens is PARFOCAL- which means that, once you set the backfocus to your camera/sensor, you can zoom in, get your focus, and zoom out. It's always in focus.

This lens is VERY WIDE. Most B4 lenses start around 8mm. This starts at 5.5mm. In M43 terms, it's like using a 7mm lens to shoot DCI 4K video.

It goes down to an f1.7. And it's a flat 1.7 across the entire zoom range. Like any very low aperature lens, the image qualty steps up once you get to f2.8 or so, but when you need those extra stops, this lens has them.

It has an internal "DOUBLER." But this one is not a full 2x, it's a 1.7x which means there's more light hitting the active image area of your sensor because the "doubler" doesn't spread it out as far as a full 2x doubler.

It has a MOTORIZED SERVO ZOOM. This means you can provide the lens 12v power (adapters are readily available on e-bay) gently push the zoom rocker, and the lens will gently creep through the zoom range- without the lens adjusting the iris in the middle of your shot like it does with still lenses. The motor can be disengaged and the lens used completely manually too.

This lens focuses down to 1-FOOT. You read that right. 1-foot. The other B4 lenses I see all have a minimum distance of several feet. But this lens you can zoom in to a very small item just 1 foot from the front of the lens and you can focus on it without even using the lens' macro.

It has a MACRO. Which means you can pull the focus even closer. And unlike other B4 lenses I've used that lock the Macro out, the Macro on this Nikon lens can be used even with the doubler engaged.

OMG! There has got to be SOMETHING wrong with it.

Well, yes, there is. When it got shipped to me from Europe, the manual/servo rocker arm got banged. It's a bit more wobbly than it should be. It still engages and disengages the motor, but you may have to wiggle it a bit. The servo motor still works, but sometimes, if it's not engaged fully, the connection between the motor and the teeth on the lens can be intermittent. If you want to open up the lens and see if you can adjust this to make it better, it's just four screws away. You could also remove the servo grip entirely and the lens would work perfectly as a fully manual zoom with teeth ready for any follow focus system you'd like to add. Personally, I like the grip because it's in the middle of the lens and it balances very nicely in my hand, even with the big Panasonic GH4 on the back of it.

I see there's actually another Nikon B4 lens for sale on e-bay right now and the grip surface around the lens is peeling away. That lens is banged up. That lens has clearly seen many years of service.

THIS lens, on the other hand, looks and feels new (except for the manual/servo switch).

It's VERY clean.

The grip is in GREAT shape, though the leather part of the hand strap does show some wear, it's perfectly functional.

The focus, zoom and iris are SMOOTH.

The doubler pops in and out beautifully.

The optics are CLEAN. Surprisingly clean.

It has a rear lens cap.

It has a front lens hood with protector glass integrated into it.

There is no front cap.

Look at the pictures.

Watch the video.

This thing is amazing and whomever wins this auction will be capturing stunning images with this lens for a long time to come.