Hi, could you clear some worrires please? I shoot only at 50p Pal System.
Do you get a better UHD video by shooting in MP4 LPCM or MOV? They are options to choose in Rec format.

Then,
I'm noticing in HDMI recording output/Bit mode 4K/50p I have the option to activate 4:2:2 10bit.
But I've always known that you can shoot in 4:2:2 only at 25p. What does it happen if I enable 4: 2: 2 10bit and I shoot at 50p?

Then:
I don't see "Color space" on the GH5 Menu. Could you tell me where it is precisely?
Thanks a lot for clearing up.

MP4 and MOV are identical. Since you don’t have an external recorder, the HDMI output options don’t have any effect on you. The GH5 only records in Rec.709, so color space isn’t an option.

The GH5 only records in Rec.709, ...
That's not quite true, HLG mode is encoded Rec2020.

Yes, but it is 25p only.

HLG is available in 10bit if you record in HD at 50P. I do not think you have the XLR unit which would give you better audio quality recording. Without that unit you should use either MP4( LPCM ) or MOV which would both give you audio at 48kh and 16 bit. With the XLR unit recording MOV you can get 48kh at 24bits or even 96kh at 24bit. Learn to read the manual pages 58 and 72. If you set the recording to 10bit in UHD 50P it cannot record internally but the HDMI output is present for recording externally to something like an ATOMOS recorder.