Why Your Stock Photos Are Killing Your Composites (And How to Fix It Before You Open Photoshop)

I once spent three days building a theatrical movie poster composite around a hero shot I pulled from a popular stock site. The lighting was dramatic, the subject was perfectly posed, and the resolution looked fine in the thumbnail. By day two, I had the background plate, the atmospheric fog layers, and the color grade all locked in. Then I tried to isolate the subject. The image was a compressed JPEG shot under a softbox, embedded in an sRGB color space, at 2,400 pixels on the long edge.