Shadow Prompts: Hardness, Direction, Length - Nano Banana 2

Edge quality comes from the size of the light relative to the subject. A small, distant source gives shadows with crisp borders; a large, near one gives borders that fade out over an inch or a foot. You do not need to explain the physics in the prompt, but you do need to pick a side.

“Hard-edged shadows with sharp outlines” produces the look of midday sun or a bare bulb: graphic, high contrast, slightly harsh. “Soft shadows with gradual edges” gives the overcast, diffused look that flatters faces and calms a scene down. Saying nothing gets you an average of the two, which reads as neither.

Length is worth naming separately because it is the clearest signal of sun height. Short shadows pooling directly under a subject read as noon. Shadows longer than the object that casts them read as the end of the day. Just writing “long shadows” is often enough to shift the whole mood of a scene.

If there are several objects in the frame, say the direction once and firmly. Inconsistent shadow direction across a scene is one of the most common tells in generated images, and an explicit “all shadows falling in the same direction, to the lower right” reduces it noticeably.