Hi, all. I've got a clip that I've filmed badly - it's very backlit. I want to set the lows to 80, mids to 60 and highlights to 20, but it seems I can only ever change one. The others are lost whenever I make the changes.
You can apply only one Gamma adjustment to and object at a time - to do what you want you would have to export the clip in between adjustments and reimport and apply the next adjustment.
Try adjusting the Lows - this will not significantly change the mids and highs. Adjust the slider to bring detail into the darkest parts the image may look as though it is now very low contrast - knock this back by applying more contrast to the image.