All-intra vs LongGOP

[Al74]

Hi All,
I have a question: When shooting moving ocean water, light reflections on water, or low-light/night footage, should I use All-Intra or Long GOP?
Best,
Alek

[Selur]

It depends:
if the format is lossless: it does not matter
if the format is not and you compare it at the same bit rate, long gop potentially will keep more details unless you use really high bitrates
(main point for all intra is that is can be easier cut)

[Al74]

I use the Lumix GH5S, shooting in V-Log L (MOV) with the choice between 400 Mbps All-Intra and 150 Mbps LongGOP. I’m asking because, in theory, All-Intra should capture complex, unpredictable motion much better. Since LongGOP uses predictive compression and averaging across frames, it seems like it would struggle with random movement compared to All-Intra, which encodes every single frame individually.

[Selur]

Yes, with 400Mbps you should be near lossless, so naturally sudden changes should not cause issues.

[Al74]

But 400mbs is for All Intra, LongGOP is 150. Hmm, so it seems that for fast, randomly  moving objects like water particles, reflections, also noise at night which could be treated by LongGOP strangely, All intra is the way to go, I plan to record in 4K of course.