Inconsistent Lighting
When shadows or light sources in an image do not align logically, implying multiple suns or impossible physics.
Lighting is often your biggest clue. In the real world, light follows strict rules—it travels in straight lines and casts shadows that actually make sense. If the sun is in the top-right, shadows have to fall to the bottom-left. Period.
The Problem
AI models like Midjourney or Stable Diffusion don't actually "know" physics. They're just guessing based on pixel statistics. They know a face usually has a shadow under the nose, but they might forget that the tree next to it should have a shadow in the same direction.
What to Spot
Conflicting Shadows: Seeing a person's shadow fall left while a building's shadow falls right? That's impossible unless you're on a planet with two suns.
Weird Eye Reflections: Zoom in on the eyes. The white reflection (catchlight) tells you where the light is. If the left eye reflects a square window and the right eye reflects a sunset, you're looking at a fake.
Floating Stuff: Sometimes shadows just don't connect to objects, making them look like they're hovering. It's a classic "video game glitch" look.
Newer models are getting better at this global consistency, but complex scenes still trip them up constantly.
Common Manifestations
The 'Two Suns' Effect: In outdoor portraits, check the subject's nose shadow versus the background building shadows. Often the face is lit from the front-left (studio style) while the city street behind them is lit from the back-right (sunset).
Studio Reflection Mismatch: A subject wearing sunglasses indoors. The glasses reflect a bright window to the right, but the shadow of their head falls to the right (implying light from the left).
How to Spot It
- 1Trace the path of shadows back to their potential source. Do they converge?
- 2Check the "catchlights" in the eyes; they must match in shape and position.
- 3Look for "rim lighting" (light coming from behind) on objects that shouldn't have it given the background.