Metabones T Speed Booster ULTRA 0.71x Adapter for Canon EF Lens to BMPCC 4K Camera

On Aps-c sensor I don't believe you will have any crop. However, in full frame you will. But there are so many advantages. I love my speed booster! Check out this video. It will pretty much answer your questions. https://youtu.be/aPIoVuerdcM

Yes, this should work fine with that lens.

The previous answer isn't really correct. The problem with EF-S lenses is physical incompatibility of the mount rather than anything with sensor coverage. Canon, for some reason, decided to make the mounts physically different to stop people from putting APS-C lenses on full frame cameras, while everyone else just wrote software to switch full frame cameras into sensor crop mode with the smaller format lenses attached. Because of factors surrounding patent expiration, this adapter uses the older full-frame EF mount and won't accept unmodified EF-S lenses. Third party APS-C lenses generally use the EF mount for the same reason and a number of them are on the tested supported list for this adapter. Metabones recommends using the 0.71x speed booster these EF mount APS-C lenses, while the 0.64x version only supports full frame lenses. Technical details: A standard m43 sensor is actually about 0.8x the diagonal of Canon's APS-C, but the imaging circle of an APS-C lens is sufficiently larger than the Canon sensor that there's plenty of margin. This is especially true since we're talking about third-party APS-C lenses, which are typically also available for other camera makes that have settled on larger APS-C sensors. Additional sidenote: There's always an exception to the rule. Despite not covering a full frame, Canon uses the EF mount on their CN-E cinema lenses.

Yes, the Metabones T Speed Booster ULTRA 0.71x Adapter for Canon EF Lens to BMPCC 4K Camera is compatible with the Canon EF 100-400mm f4:5-5:6L IS II USM lens on the Blackmagic Design Studio Camera 4K Plus G2.

If it's an electronic smart EF lens yes.

Yes, the Sirui Jupiter 35mm T2 Full Frame Macro Cine Lens (EF Mount) is compatible with the Metabones T Speed Booster ULTRA 0.71x Adapter for Canon EF Lens to BMPCC 4K Camera.

The Pocket 4K has a 1.9x crop factor and this makes a lens 0.71x wider. If you have a 24mm full frame lens you would follow this formula: 24 x 0.71 = 17 x 1.9 = 32.3. So instead of a 24mm being around a 45mm on the Pocket 4K, it is now around a 32mm.

As per manufacturer product description: The T Speed Booster ULTRA 0.71x adapter supports electronic communication between an attached camera and lens. If the lens includes autofocus, image stabilization, and camera-controlled aperture functions, this adapter is intended to allow those features to be used. Also, if an attached lens is capable of generating EXIF metadata when used with a directly compatible camera, the T Speed Booster ULTRA 0.71x adapter is designed to allow that information to be saved along with image files generated with a combination of the lens, a BMPCC 4K camera, and the adapter. The overall results are going to be very noticeable as well.