The Truth About Negative Fill: John Gress Busts the Biggest Lighting Myth

Our favorite commercial photographer, John Gress, is on a mission, and this time it’s personal. In his studio, armed with a black V-Flat, a few softboxes, and his model Jake, John sets out to debunk one of the most misunderstood concepts in photography lighting: negative fill. He’s not just poking holes in internet tutorials – he’s tearing down a myth that's misled countless photographers for far too long.

Negative Fill Isn’t What You Think It Is

You’ve probably heard people say negative fill “sucks light” out of the shadows. That’s the phrase John hears all the time – and it drives him nuts. Negative fill isn’t some magical black hole. It doesn’t pull light out of shadows. Instead, it does something much simpler: it blocks light from bouncing into the shadows.

This misunderstanding usually comes from seeing black flags or V-Flats placed on the shadow side of the subject. The assumption is that these black panels are actively darkening the image by absorbing light. But as John shows in his demos, that’s not the full story.

Demo 1: No Reflective Surfaces, No Difference

In the first demo, John positions Jake with a soft key light and brings in a black V-Flat on the opposite side. But there’s not much over there to reflect light anyway – a concrete column, a few bits of gear, and a white box, none of which bounce much light back. So when the V-Flat goes up? Almost no visible difference in the shadows. That’s because there wasn’t much reflected fill to block in the first place.

Demo 2: Black Side vs White Side

In demo two, he repeats the setup, but this time shows what happens when you flip the V-Flat to its white side. Now, there’s a dramatic change. The white surface adds reflected light into the shadows, noticeably lifting them. This contrast shows what the black side is really doing: it's preventing that reflected light from happening, not sucking light away.

Demo 3: Blocking the Bounce

The final setup is the most telling. John places a large piece of white foam core across the room to act as a bounce. Then he puts the black V-Flat between himself and the foam core. When the V-Flat is up, his shadows deepen – because the reflected light can’t reach him. When it’s taken down, those same shadows brighten instantly. It’s a clean illustration: negative fill is just strategic shadow control.