* Wide-angle lenses (under 35mm): These lenses exaggerate perspective. Faces appear distorted, with features closer to the camera appearing larger than those further away. The nose can look disproportionately large, and the face can appear wider and less flattering. This effect is more pronounced the closer the subject is to the camera. However, wide-angle lenses can also be used creatively to emphasize environment and context within the portrait.
* Standard lenses (around 50mm): Often considered the most natural perspective, standard lenses produce a relatively undistorted image of the face, closely resembling how we see with our own eyes. They offer a good balance between perspective and compression, making them popular for classic portraiture.
* Telephoto lenses (85mm and above): These lenses compress perspective. The distance between facial features appears reduced, creating a flatter, more two-dimensional look. The background is also compressed, leading to a shallower depth of field and a more pleasing bokeh (blur). This compression effect can be very flattering for portraiture, slimming the face and minimizing imperfections. The resulting images often have a more elegant and classic feel.
Specific effects on facial shape:
* Compression (Telephoto): Reduces the perceived width of the face, making it appear slimmer and more elongated. It can also minimize the prominence of the nose and chin.
* Exaggeration (Wide-angle): Increases the perceived width of the face, making it appear wider and potentially more round. The nose and other features closer to the camera are emphasized, often unflatteringly.
* Perspective Distortion (Wide-angle): Can lead to a "fish-eye" effect (though usually less extreme in slightly wider lenses than true fisheye), curving lines and distorting features.
* Depth of Field (all focal lengths): The aperture (f-stop) also interacts with focal length to control depth of field. Wider apertures (lower f-numbers) with telephoto lenses create a shallow depth of field, blurring the background and focusing attention on the subject's face. This enhances the subject separation and flatters by drawing the eye to the key features.
In summary, the choice of focal length is crucial for shaping the aesthetic of a portrait. While telephoto lenses often provide a flattering compression, wide-angle lenses can be used creatively for dramatic and expressive results, but often require more careful positioning and awareness of the perspective distortion. Understanding these effects allows photographers to choose the best lens for the desired look and to effectively control the narrative conveyed through the portrait.