Same Light: did your skincare work, or did the light change?

Skin-analysis apps score a photo, not your skin. Same Light, built on the YouCam (Perfect Corp.) skin API, answers the question a before/after comparison usually hides: did the treatment work, or did the light change?

Try it with sample faces: same-light.onrender.com · Code: github.com/bisale24-ops/same-light · Demo: youtu.be/hvygpxSM6fo

Measures the light first. The scanner is deterministic for the same photo, but the same face under warm and cool light scored up to 11 points apart on one concern, enough to fake progress.

Compares only like with like. It checks the lighting of the before and after photos and warns when the change is within the noise band measured for each concern.

Shows its evidence. Every verdict lists the measured difference next to the noise band, so a user sees why a change counts or not.

The YouCam API hackathon on Devpost. Python with a standard-library server on Render, 20 tests; the light experiments are in the repository so the numbers can be re-run.