Key Concepts to Understand:
* Perspective: How the relative sizes of objects in the scene are rendered in the photograph. This is primarily affected by the distance between the camera and the subject.
* Compression: The effect of making objects appear closer together in the image than they are in reality. Longer focal lengths increase compression.
* Distortion: Deviation from a realistic or accurate depiction of the subject. In portraits, this is often perceived as unnatural stretching or shrinking of facial features.
* Working Distance: The distance between the camera and the subject. You need to move further away with longer focal lengths to achieve the same framing.
How Different Focal Lengths Affect the Face:
* Short Focal Lengths (e.g., 24mm, 35mm):
* Increased Distortion: These lenses exaggerate the size of features closer to the camera (like the nose) and make features further away (like the ears) appear smaller.
* Wider Perspective: They capture a larger field of view, including more of the background.
* Less Flattering: Generally considered less flattering for portraits because of the distortion, especially when used close to the subject. The face can appear stretched or "fish-eyed".
* Great for Environmental Portraits: When you want to show the subject within their surroundings, a wider lens can be useful, even if it means some facial distortion is present. The environment becomes part of the story.
* Proximity: You need to get very close to the subject to fill the frame, which can feel intrusive.
* Medium Focal Lengths (e.g., 50mm, 85mm):
* More Natural Perspective: These lenses offer a more balanced and natural-looking perspective, closer to how we perceive faces in real life.
* Less Distortion: Minimal distortion, providing a more accurate representation of facial features.
* Versatile: Good for headshots, and upper-body portraits. 85mm is often considered a classic portrait lens.
* Working Distance: Allows for a comfortable working distance, neither too close nor too far.
* Long Focal Lengths (e.g., 100mm, 135mm, 200mm+):
* Compression: These lenses compress the scene, making facial features appear closer together. This can flatten the face, making it appear wider and reducing the prominence of features like the nose.
* Less Distortion (Generally): Minimal distortion, especially at longer distances.
* More Flattering (Often): The compression can be flattering because it can smooth out perceived imperfections and create a more streamlined appearance.
* Background Blur (Bokeh): Long lenses provide excellent background separation and bokeh (blurred background), which can help isolate the subject.
* Working Distance: Requires a greater working distance, which can be beneficial for making the subject feel more relaxed and comfortable.
* Potential Downsides: Can sometimes make the face look too flat or "pancake-like" if overused. Communication with the subject can also be challenging at very long distances.
Practical Examples:
* 24mm Portrait: Nose looks huge, ears look small, face seems stretched. Background very prominent.
* 50mm Portrait: A good starting point for portraits. Features are generally accurate and balanced.
* 85mm Portrait: A classic choice. Slight compression, flattering perspective, good background blur.
* 135mm Portrait: More compression, background is very blurred, can create a very polished look.
* 200mm+ Portrait: Significant compression, requires a lot of space, can be very flattering but may also flatten features excessively.
Which Focal Length is "Best"?
There is no single "best" focal length for portraiture. The ideal choice depends on:
* The desired aesthetic: Do you want a realistic, compressed, or more dramatic look?
* The environment: Do you want to include a lot of the background or isolate the subject?
* Your comfort level: Are you comfortable working close to the subject, or do you prefer more distance?
* The subject's face shape: Some focal lengths are more flattering for certain face shapes than others.
Experimentation is Key:
The best way to understand how focal length affects portraits is to experiment with different lenses and observe the results. Pay attention to how the proportions of the face change and how the background is rendered.
In summary:
* Short focal lengths (wide-angle): Distortion, exaggerated features, wider perspective.
* Medium focal lengths (standard): More natural perspective, minimal distortion, versatile.
* Long focal lengths (telephoto): Compression, flattened features, background blur, often considered flattering.
Understanding the effects of focal length is essential for creating compelling and flattering portraits. Choose the lens that best suits your vision and the subject you are photographing.