GH4 video judder/strobing - a solution

Rollo145 wrote:

Was pleased to find your thoughts on gh4 judder. Have been using gh4 for 3 months and have spent the last week in forums etc trying to find solution to that problem that's been bugging me every time I shoot video. Your thoughts are the only one having any sense. The many who claim this judder is normal film-making issue for all panning in low frame rate regrettably do not understand the problem. I live in a 50Hz PAL country and shooting in 1080p. I tried some shots last night using your suggestion to change to 60hz system frequency and yes, all was smooth again. So today I took it out in the street and did a series of comparisons at 50 and 60Hz sys frequency at different frame rates.

On viewing the clips it is quite obvious to me that the 60Hz clips are totally smooth and buttery, both at 60 fps and almost as good at 30fps. Exactly what you would hope for in high quality video/film output. The clips at 50Hz are all totally unacceptable having that pumping frame jerk on pans and things passing through the frame. My conclusion is that the whole system is 60Hz and the data is converted to 50Hz in-camera. I think they just knock off one frame every 5 (to make 60 fit 50). That would make jerks at 5 per second (at 25fps) or 10 per second (at 50fps). And that's what it looks like to me. Guess I'll contact Panasonic next to see if they other ideas or what.

I will try editing my footage to demonstrate the issue.

Many thanks for your explanations in DPReview.

Rollo...

yes it's totally aggravating, annoying, etc!!!

but its all to do with the playback monitor, not the capture of the GH4.

Within the last several years the world has become dominated by 60Hz LCD panels, most desktop computer LCD monitors, laptop screens, AND the LCD monitor on the back of the GH4 + the EVF in the GH4, etc.

25fps just will not play smoothly on 60Hz screens.

...though most LCD TVs in Europe will play 25/50Hz just fine as they need to remain compatible with all the footage shot for 50Hz.

If you intend your footage for TV broadcast in Europe your 25fps footage will flow smooth, but on many desktop computer LCD monitors, laptop screens, AND the LCD monitor + EVF of the GH4, it will look juddery. It's the playback device, there's no way around it.

If you want your footage to look great on a computer (which will include laptops) you need to shoot 30fps (29.97fps will judder ever now and again but you might not notice).

If you want your footage to look great for broadcast on a UK/Europe TV you need to shoot 25fps.

Blu-Ray is 24p though can be 50i, so 25fps footage is fine there also.

If you successfully contact Panasonic Re: the GH5 GH6, please say can they employ a LCD + EVF that can switch to 25/50Hz (rather than 30/60Hz) when a frequency of 25fps is selected.

Glad I could help, or at least concord with your findings!