Ok, I know Andrew says that the 5D MK IV isn’t the same, but I only have the 5D and I decided out of curiosity to test against a GH5, after all the 5D MK IV has a reputation for softness due to the strong sensor filter, etc.
I shot a number plate at 100mm, on a tripod, manually focused. These cameras are mainly used for photography so all at default sharpening, Canon 70-200mm f4.0 IS at f4.0. Pana 12-60mm f2.8-f4.0 at f4.0. UHD for GH5 and 4K for Canon.
Canon set to 100mm, Pana set to 50mm.
To equalise the framing in post, in the nle, I zoomed in on the GH5 clip to best match the Canons crop. I then captured a jpeg from both clips and compared. They were close, but the better of the two was the Canon.
This surprised me.
I wonder is it possible that Max Yuryev is using a different methology, i.e. maybe zooming the Canon less on the tripod to better match (because of Canon 4K crop) the other cameras?
Thing is, if the latter method is used then the Canon is at a disadvantage because for a fair comparison the optical combination of Camera and lens should be the same.
Of course if in the real world you were say shooting a fixed distance event, say a play or something, then the GH5 may well produce a better image because the Canon would need to be zoomed out, shot wider, if it was used to shoot the same event in 4K, and keep the correct framing.