Why Your Composites Look Fake (And the Lighting Math That Fixes It)

The Moment I Realized Light Was the Whole Game Years ago, I finished a composite for a book cover, sent it to the client, and got back nothing but praise. The publisher loved it. The author posted about it. I printed it out and pinned it to my wall. Then I noticed it. The shadow on the main subject was falling to the left. The background plate, a moody overcast field, had the light source sitting clearly to the right.