Distortions in Cinematography!

Understanding Distortion in Cinematography – A Detailed Summary (with Sensor Size and Flange Distance Influence)

Distortion in cinematography refers to how lenses change the appearance of objects or actors in a frame, especially near the edges. It alters the size, shape, or proportions of objects, creating a perception different from what the human eye normally sees. Distortion is influenced by several factors, including the focal length of the lens, the camera’s sensor size, flange distance, and the camera’s distance from the subject. Wide-angle lenses cause more noticeable distortion, while telephoto lenses tend to compress the image and minimize distortion.

Types of Distortion:

1. Barrel Distortion (Wide-Angle Lenses):

Objects seem to bulge outward from the center.

Straight lines at the edges of the frame curve outward.

Facial features like eyes and noses are exaggerated, with large eyes and prominent noses, while the outer face (cheeks, ears) appears smaller.

2. Pincushion Distortion (Telephoto Lenses):

Objects pinch inward towards the center.

Straight lines at the edges curve inward, creating an opposite effect of barrel distortion.

Telephoto lenses flatten the space, softening the appearance of facial features, which can create a smoother, more refined look.

Effects of Distortion on Actor’s Faces:

1. Size and Proportion Changes:

Wide-Angle Lenses:

The closer the face is to the lens, the more exaggerated it looks. For example, the nose may appear disproportionately large.

Eyes can look larger, which could be useful to highlight emotions or expressions.

Features like the jawline may shrink, creating a more cartoonish or youthful appearance.

Telephoto Lenses:

Flatten and smooth facial features, making actors look more polished or elegant.

Sharper angles, such as a strong jawline or high cheekbones, become softer and more glamorous.

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2. Perspective Distortion:

Wide-Angle Lenses: Stretch the space between facial features, making the nose look farther from the rest of the face. This creates a dynamic but sometimes unnatural look.

Telephoto Lenses: Compress features, making them appear flatter and more uniform, giving a balanced and elegant appearance to actors.

3. Edge Distortion and Vignetting:

Edge Distortion: Wide-angle lenses cause features near the frame’s edges to stretch or warp. Actors positioned at the edges may have elongated faces or bodies. This technique can be used to create unease or dramatic tension in a scene.

Vignetting: Some lenses darken the edges of the frame, pulling attention to the center, creating a halo-like effect around an actor’s face.

4. Background Separation and Depth of Field:

Wide-Angle Lenses: These lenses have a large depth of field, keeping the background in focus. This shows the actor in clear relation to their surroundings, emphasizing both the actor and the context of the environment.

Telephoto Lenses: These blur the background, isolating the actor, creating a dream-like or romantic effect by focusing solely on the actor and minimizing distortion.

5. Movement Distortion:

Wide-Angle Lenses: Exaggerate motion. As actors move toward the camera, the movement feels accelerated, with more noticeable distortion of facial features. This can be used for comedic or dramatic effects.

Telephoto Lenses: Offer smoother, more graceful movements, often used in romantic or elegant scenes where a polished look is preferred.

Sensor Size and Distortion:

The size of the camera’s sensor plays a significant role in how distortion appears in cinematography. Larger sensors (like those in full-frame or large-format cameras) require lenses that cover more of the image circle, meaning that distortion might appear more pronounced, especially toward the edges of the frame. With smaller sensors (such as in APS-C or Micro Four Thirds cameras), only a smaller portion of the lens’s image circle is used, which can reduce the visible distortion.

Full-Frame Sensors: When combined with wide-angle lenses, they produce more visible barrel distortion because they use the full image circle. Actors filmed at the edge of the frame will have more stretched or warped features.

Smaller Sensors: These sensors crop the image circle, cutting out some of the edges where distortion is most visible, thus reducing the noticeable warping, especially when using the same lens designed for a full-frame camera.

Flange Distance and Its Influence:

The flange focal distance (the distance between the camera’s sensor and the rear element of the lens) impacts distortion, particularly when adapting lenses from different systems. A shorter flange distance allows for lenses to be positioned closer to the sensor, which is why mirrorless systems, with their shorter flange distances, often provide more flexibility in lens choices.

Short Flange Distance: This enables the use of a broader variety of lenses, including those with minimal distortion. However, it can also lead to more pronounced distortion with wider lenses if the camera system is not designed to correct it.

Long Flange Distance: Cameras with longer flange distances (such as DSLRs) may reduce the range of available lenses, but can still produce distortion if paired with lenses not optimized for their system.

Focal Length and Framing:

Close-ups and Medium Shots: A 35mm lens in close-ups introduces barrel distortion, making certain features like the nose or eyes stand out, while a 70mm or 85mm lens provides a more flattering, compressed view that’s commonly used in glamour shots.

Wide Shots: In wide shots, distortion from a wide-angle lens enhances the scope of the scene, making the actor appear smaller in relation to their environment while adding drama to the composition.

Distortion, influenced by lens type, sensor size, and flange distance, is a creative tool in cinematography. Understanding how these factors interact allows filmmakers to manipulate the visual appearance of actors and scenes, using distortion to enhance or alter emotional tone, emphasize physical features, and communicate story elements. Whether using distortion to create tension or highlight beauty, these factors combined can transform technical limitations into artistic opportunities, adding depth and intensity to the cinematic experience.

Drafted by

CJ Rajkumar

Author/ Cinematographer