Original
Gray sphere, neutral key + fill.
No exposure adjustment.
One scene. Three different reasons it changes.
Gray sphere, neutral key + fill.
No exposure adjustment.
The sphere’s material is edited.
The reference cube’s material stays fixed.
The key light is edited.
A neutral fill stays on for comparison.
The entire image is adjusted.
No light or surface has changed.
How the surface responds
Watch the reflection become sharp or broad. Roughness changes the reflection—not the shape of the sphere.
What illuminates the scene
Watch both objects and their shadows. Turning off the key does not turn off the fixed fill light.
How bright the image appears
Watch the sphere, cube, floor, and background together. Highlight and shadow positions do not move.
This image uses all three current settings together. The four cards above still isolate one category at a time.
Compare an original and a mystery render. Decide whether the change came from the material, light, or exposure.