A couple of days ago I wrote to Metabones:
"Will Speed Booster XL 0.64x m4/3 work with the BMPCC 4K or are you developing a new booster especially for the new BMPCC 4K?"
Their answer:
"Sorry! We still waiting a test with BMPCC 4K …."
This is what I do now: selling Super 16 c-mount lenses which I used with the BMPCC and bought the Speed Booster XL with a full frame Tokina AT-X-Pro 28-70mm F2.6-2.8 (Poor man's Angenieux) and started to invest in a set of Leica R lenses.
BMPCC 4K have sensor's diagonal 21.44mm. Metabones 0.64x for BMCC is not suitable for BMPCC 4K because it covers image circle 18.2mm only.
Metabones Nikon G to Micro Four Thirds Speed Booster XL 0.64x have image circle 21.63mm. So it fully covers a new sensor of BMPCC 4K!
Anyone knows image circle of Metabones BMPCC 0.58x Speed Booster? I think it is smaller that IC of BMCC.
I have recently got for my old Pocket a good power solution. It works more than 5 hours with this power bank powered by 5x hi quality 18650 batteries. You can also put it in a cell phone tripod mount to attach it to the camera. You need to get a LEMO connector to power a new BMPCC4K.
1. Power Bank 5x18650 QD 185-TY ($20.8) https://www.dhgate.com/product/18650-power-bank-case-battery-holder-output/388633847.html
Size: 13cm* 8cm*2.0cm (5.1' x 3' x 0.8').
2. 5x VariCore New Original 18650 NCR18650B Rechargeable Li-ion battery 3.7V 3400mAh ($14.7) https://ru.aliexpress.com/item/4pcs-lot-2015-100-New-Original18650-3-7V-3400mah-NCR18650B-Lithium-Rechargeable-Battery-For-Panasonic-batteries/32433452171.html
3. Universal Cell Phone Tripod Mount ($3.9) https://ru.aliexpress.com/item/OOTDTY-Universal-Cell-Phone-Tripod-Mount-Clipper-Vertical-Bracket-Holder-360-Degree-Adjustable-4XFC-Drop-Ship/32833106727.html
3. 2 pin LEMO connector for BMPCC4K ($7.3) https://ru.aliexpress.com/item/LEMO-Connector-FGG-0B-2-3-4-5-6-7-9-Pin-Male-Connector-0B-FGG/32836029840.html
GH5s sensor size: (19.2 x 13 mm) https://***URL removed***/reviews/panasonic-lumix-dc-gh5s-review/2
The BMPCC4K's sensor is physically larger than its effective size 18.96mm x 10mm.
Cinematographers often use diffusion filters to make image more soft, film-like, less digital looking. So high resolution is not always the very important part of a good looking picture.