GH4 video judder/strobing - a solution

I've tried shooting in 24p c4k and its juddering everywhere.

...unless you have a very powerful Mac, I'd advise editing 4K in a 1080p timeline, then rendering, then play it back (in FCPX). Playing 4K (rendered) will judder; you'll need more that quad-core for sure!

I read recently about setting the shutter angle to 180 and syncro scan not tried that yet but reading this I'm not confident.

I use 240 degree shutter angle, just a bit more useful blur when panning, but still sharp with static. 360 degrees will look more dreamy. On occasion I do use 180 degrees, but never less! Just set the shutter angle, don't bother with syncro scan.

I temporarily solved the issue by selecting the clips that I noticed it the most (pans/tilts) optimising them in fcpx then half speed, optical flow then put it back to normal speed. As I say this is only a temporary fix and very very time consuming.

That probably doubles the blur, so if you are using a 180 degree shutter angle, your workaround probably simulates 360 degrees. I'd use your preferred shutter angle to start with, in camera.

I like the sound of the 29.97 being smooth and will do some testing tomorrow. (Can 29.97 be burned to dvd and blue ray with no problem on playback)

I use 25fps as I live in the UK, and film here and in Europe. 25fps is required by TV broadcast companies, and doesn't cause flickering issues with 50Hz mains lights. Although not part of the original spec of DVD / Blu-Ray, 25fps is supported by 99% of DVD / Blu-Ray players.  I'd advice mastering to Blu-Ray, taking GH4 footage and squeezing it onto outdated DVD will severely harm the quality! GH4 footage (4K > 1080p) on Blu-Ray looks great!

Is there any way of passing this thread onto panasonic for answers?
I filmed with the GH3 for 6 months everyday on a world trip and had no problems, shooting in 50p (love that slow mo) but have seen juddering from the GH3 online. I will test the 72mb 24p GH3 along side my GH4 tests tomorrow.

50p on the GH4 will look v.smooth.

I advise 25fps, 4K, edited on a 1080p timeline.  You can look up pan speeds, there's a table online of how quick you can pan across the frame, keep it as slow as possible (though extremely fast pans are ok too!).  Watch TV dramas, background pans will judder even with their top equipment, just needs managing!