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Nikkor lenses and the BMPCC 4K

PostPosted: Sun Jun 23, 2019 7:25 pm
by Mhoganphoto
Hi there!

This is my first post on a board that I’ve been learning a lot through over the past few weeks. I’m currently saving up for the BMPCC 4K, and currently am shooting video on a Nikon D850 with multiple Nikon and Sigma art lenses that are F mount.

With that being said, seeing as how I won’t have a huge budget for new MFT lenses, what adapter do you recommend? Metabones? Viltrox? Which multiplication factor?

This is all new to me, so I’m thankful for the help!

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Re: Nikkor lenses and the BMPCC 4K

PostPosted: Tue Jun 25, 2019 1:50 am
by Denny Smith
I would use the Metabones Ultra Nik/MFT (0.71) SB, which will have you a field of view similar to a Nikon’s DX Sensor.

Re: Nikkor lenses and the BMPCC 4K

PostPosted: Tue Jun 25, 2019 12:37 pm
by David Hutchinson
What do you want to do with the crop factor? I use the BMPCC4K with a Sigma 600mm FF lens and I simply use a mount adapter without any glass. With the crop factor this gives me the equivalent of almost 1200mm. It works really well for my wildlife shoots - so you don't always need the Ultra expensive metabones - just depends on what you're shooting.

Re: Nikkor lenses and the BMPCC 4K

PostPosted: Tue Jun 25, 2019 12:45 pm
by Mhoganphoto
I’m looking to shoot mostly documentary work, and have a 17-35 f2.8, 35 f1.4, 50 f1.4, 85 f1.4, and a 80-200 f2.8.

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Re: Nikkor lenses and the BMPCC 4K

PostPosted: Tue Jun 25, 2019 2:21 pm
by ttakala
I have the Viltrox NF-M43x focal reducer 0.71. It's decently sharp when you stop down one stop or more. Bigger issue is ghosting, when there is something very bright in the frame or just outside the frame. Good lens hoods / matte box is required. I haven't tested the Metabones speedbooster but according to some comparisons that I've seen, it probably is better, albeit 4-5 times more expensive.

David has a good point about using the crop factor to you advantage. I also have the K&F Concept adapter (without glass), which effectively stretches my Ai 300 mm to almost 600 mm. The same thing happens at the wide end of course. My widest lens is the Nikkor AF 18-35 which is usually wide enough with the Viltrox but would give a full frame equivalent FOV of 34-67 mm with the K&F. The K&F adapter is solidly built but the attached lens reaches infinity before the infinity mark on the lens. I thought about trying to adjust it by cutting some shims under the lens mounting plate but I rarely use it so haven't gotten around to it yet.

Since you're coming from a full frame DSLR, the Metabones XL 0.64 would give you a more familiar field of view. Viltrox doesn't make an equivalent to that. Metabones also announced a new speedbooster optimized for the BMPCC4K, but it's not available yet. Maybe buy the Viltrox (I think I payed 100 euros for mine) to get you started and upgrade to the new Metabones when it comes out...

Re: Nikkor lenses and the BMPCC 4K

PostPosted: Tue Jun 25, 2019 6:58 pm
by Mhoganphoto
Would there be bad vignetting at .64x?

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Re: Nikkor lenses and the BMPCC 4K

PostPosted: Tue Jun 25, 2019 8:10 pm
by ttakala
Assuming your lenses are meant for full frame cameras, there shouldn't be any vignetting at 0.64x. If you have DX lenses, you should go with the 0.71x to avoid vignetting. The image circle of DX lenses is smaller than FX and film era lenses.

The crop factor of Pocket 4K is about 1.9. With a 0.64 focal reducer that would become 1.9*0.64=1.22. Which is still cropped compared to a full frame DSLR. So if anything, you will get less vignetting than with a Nikon FX camera.

This video explains speed boosters and crop factors:

Re: Nikkor lenses and the BMPCC 4K

PostPosted: Tue Jun 25, 2019 8:30 pm
by Michael Kropfberger
I also came from the Nikon D800 and went with two bmcc4ks and two Viltrox NF-M43x, also the 3x K&F Concept...
I've mounted quite some lenses within reasonable steps (with viltrox vs. no-glass) to be ready without having to clumsily switch adapters....

I use eg. Nikkor 20mm 2.8, 60mm 2.8, AF-s 50mm 1.4, 35mm DX 1.8.
besides that, I also went with Meike 16mm and 25mm, and cant wait for the other focal lengths... filming for me is focus pulling with a long throw... well, older nikkon lenses are reasonable long, but far from what the Meike can do...

I also use the Nikon 70-200 with the TC17 to be 340 and then with the K&F, to get 680mm...
or the sigma 150mm 2.8 with K&F, which is still 300mm...

see the long tele lenses in use here:

ONE NOTE: if you have the 24-70 Version I you are good with manually setting the iris, but the newer Version II doesnt have the manual latch anymore, so you are stuck to 2.8 !!!!


Re: Nikkor lenses and the BMPCC 4K

PostPosted: Wed Jun 26, 2019 9:38 am
by ttakala
Beautiful footage, Mike!

Ah, so you keep the adapters together with the lenses and swap the whole package at once, like a "native" MFT lens... Interesting.

Since the 18-35 + Viltrox 0.71 combo is not quite as wide as I would like sometimes, I've been thinking about adding a superwide MFT lens to my collection. However, I want to avoid switching the adapters back and forth. There is a little bit of rotational play with the Viltrox to Pocket 4K so I have mounted it to the camera with a bottom plate. It's really nothing severe but I guess I have a low tolerance for loose things. Anyway, this mounting plate makes it extra cumbersome to take the adapter off. One good thing about keeping it on the camera is that no dust gets on the sensor!

In the video that I linked, they talk about the electronics of the Canon mount speedboosters. I don't think that any of the Nikon adapters have electronics. So you need to have a manual aperture ring in the lens or in the adapter. And of course autofocus will not work. K&F Concept make two different versions of the adapter, one that has aperture control and one that doesn't. The Viltrox NF-M43x has an aperture ring. I taped it in place, because all my lenses have manual aperture control. It was confusing to have two aperture rings.