Premiere Pro CC 2018
I was baffled,
Not understanding why my dissolve transitions in a new Premiere project are not linear, and too lift too fast,
I validated this in the Lumetri Scopes window.
In an older project, at 50 percent transition duration, white color is at 50 percent intensity like you’d expect from a linear transition.
But in my new project, at 50 percent transition duration, white color is at about 75 + percent intensity as if it’s gamma corrected.
After some web research in discussion groups, I found that the option that doe’s that is:
Sequence Settings > Composite in Linear Color
And unchecking it solves the problem.
It’s still weird to me that Composite in Linear Color breaks the linearity of the dissolve transition,
But at least there is a solution.