Mastering AI Portraiture

Artificial intelligence does not just "draw" images; it simulates optical physics and photography principles. Understanding the technical science behind the prompts is what separates a generic AI image from a professional masterpiece. This guide dives deep into why certain parameters result in world-class photography.

The Optical Science of Focal Length

When you browse PromptHaven, you'll often see lens specifications like 85mm or 35mm. In traditional photography, an 85mm lens is the "gold standard" for portraits. It provides a flattering compression of facial features, ensuring the nose and ears appear in natural proportion while creating a beautiful separation from the background.

• 35mm Lenses: Best for "environmental portraits" where the background tells as much story as the subject.
• 85mm/135mm Lenses: Ideal for high-fashion and emotional headshots, focusing purely on facial expressions and lighting textures.

Lighting Physics: Beyond Brightness

Lighting in AI generation is the language of emotion. Professional prompts use lighting techniques borrowed from the Renaissance era and modern cinema:

Rembrandt Lighting: Named after the famous Dutch painter, this technique creates a small inverted triangle of light on the subject's shadowed cheek. It adds a sense of drama, mystery, and incredible depth to AI portraits.

Volumetric Lighting: Often referred to as "God rays," this simulates light hitting particles in the air (like dust or fog). It gives your AI-generated scene a sense of three-dimensional atmosphere that a flat prompt simply cannot achieve.

The Importance of Aperture and "Bokeh"

Parameters like f/1.8 or f/2.8 instruct the AI to mimic a wide aperture. This creates Bokeh—the aesthetic blur of the out-of-focus background. This is crucial for professional work as it eliminates background distractions and locks the viewer's gaze on the subject's eyes, the most important element of any portrait.