GH4 video judder/strobing - a solution

Edgar F wrote:

Finally some light is shed on this subject... I too see this awful strobe effect while panning and it really messes everything up. Why isn´t this more known? And what about other cameras? Red? Alexa? C300? Sony A7?

I think they are all much the same, professionals know this 'effect', and take measures to minimise it, slow pans, blurred backgrounds. I often see strobing on current TV dramas (using RED, Alexa).

The softer the detail, the more blurred the background, the less strobing will appear, definitely worthwhile using lenses with their aperture wide open. The GH4 is also much sharper than equivalent canons; we like the extra sharpness but this also brings with it extra strobing. A larger sensor will also help to keep backgrounds blurred. Normally you would be tracking a foreground object/person, and the background would be moving - and so should be kept out of focus.

Reading the whole thread I wonder if you ever tried shooting 29.97 and interpret footage to play like 24 and see if its still visible the strobe effect?

I have taken footage at 24 (which looks like it is strobing) and placed it directly into a 30fps timeline, speeding it up, it looks silky smooth. 30fps is also the frequency most LCD monitor operate at, so each frame is shown on each refresh of the screen, no doublings of frames every second - which causes 24/25fps to judder.

Judder, is caused by 30hz LCD monitors (and TV's) doubling frames from 24/25fps footage.

Strobing, is a flick-book effect mostly seen on high contrast edges and are not sufficiently blurred.

And what about MMKz saying "Anyway,the strange thing is, when you are in Creative Mode (manual FPS control from 1FPS-96FPS) and set it to 24fps, everythings looks smooth!

I was surprised by this, I tried it thoroughly and the results were no different, I think MMK must have been mistaken.

What the hell is wrong with this camera?!"

Not much

Doesn´t that contradicts the idea of the problem being from Monitor or LCD frequency?

No, judder is caused by a mismatch on footage taken at 24/25fps being displayed on a 30Hz/30fps screen. It may also be caused by your computer not being up to 4k playback, you'll need at least 6-core, the GPU also needs to be high-spec to shrink the 4k down to screen res. I recommend always rendering 4K down onto a 1080 timeline, unless you have the need and means to deliver 4K.

Strobing, to minimise, requires slow panning, blurred backgrounds, reduced contrast.

Hope that helps.