I am new to the GH4 and have just shot a low light music video. The footage looked great when I was shooting but when I put the card into my computer from then on the footage looks much darker - it looks as if I've drastically under-lit the scene. But through the camera it's much brighter and perfectly well exposed. I have checked that the LCD brightness setting is set to the middle, and I've run through the camera settings I was using and can't see anything untoward there. I was using a variety of lenses, some 4K and some HD slow motion, and the problem is consistent throughout. I am holding on to the hope that if it looks great on the viewfinder the information must be there because I can see it, but in post it's almost beyond grading and would add considerable noise if I were to boost the brightness sufficiently. I am baffled. Any help out there? It would be much appreciated.
Here's a photo which will give you an idea. These are from the same piece of footage (give or take a few frames), seen in-camera compared with direct from the SD card. If you try to ignore the discrepancies created by my phone camera, you can see the exposure is considerably different.
In my experience you can't judge exposure from the LCD screen on ANY camera - let alone a GH4. Or if you can it's more by luck than design.
The GH4 has a really nice OLED monitor but it's nowhere near calibrated to something you can use to judge exposure. Then I've got to ask how well is your computer screen calibrated? How far out do the waveforms in your NLE say you are?
Use the histogram, zebras, or exposure meter to get it right on set - that's what they're there for. Even better, get a good calibrated external monitor with waveforms and false colour, it really takes all the guesswork out of it.