Traditionally raising the master pedestal would simply "grey" the blacks...reducing the amount of captured dynamic range. I've seen some tests that seem to indicate that the GH4's setting does not behave this way. It seems to keep black at 0 (or 16) and open up the shadows...more like a gamma curve... without adding any shadow noise.

For an example, check out this test: https://vimeo.com/groups/gh4k/videos/102012007

My camera was stolen :-( so I can't test until my replacement arrives. Can anyone confirm or refute this apparent behavior? If it does work like a curve, then this is really good news for getting more out of the shadows. (Remember it's easy to crush shadows in post, it's very hard to recover.)