Pick the camera you're shooting on, dial in a focal length and aperture, and choose the frame rate. The other cameras show you the lens settings that would give the same framing (angle of view) and the same depth of field.
Match Framing + DOF mode: shows what lens/aperture to use on the other two bodies to reproduce the shot.
Show FF Equivalents mode: shows the full-frame-equivalent focal length and aperture of the shot — handy when crews talk in FF numbers.
High frame rate crops (from DPReview / B&H / CineD lab tests):
· A7S III 4K 120p: 1.1× extra crop → 1.10× effective
· A6700 4K 120p: 1.58× extra crop → 2.37× effective
· GH5S: no 4K 120p; FHD 120p has no extra crop → 2.00× effective
Math: ff_focal = focal × effective_crop, ff_aper = f × effective_crop.
Note: aperture scales DOF and total light gathered, not exposure — ISO/shutter behaviour is unchanged.