captainsolo said:

Joker's reveal is a great example of how to do this. No matter what I put my levels at, no transfer can have the face in complete darkness. There is an outline where you can make out a face just barely, and if you are looking closely enough you can make out a faint ghostly visage. That's about what I think the print would have resembled. It also feels like something Burton would do-almost Grissom's A Christmas Carol for a brief second.

This is in fact exactly what the release print looked like - you could just about see the face, but it wasn't possible to make out the makeup until he stepped into the light. At the time I was wondering if the transformation had simply left him 'messed up', and then the makeup would be subsequently applied to disguise the fact (an idea that Nolan's Joker would employ nearly 20 years later).