Optical distortion plays a fundamental role in shaping an image; you can either correct for it or embrace it, depending on the story you want to tell. Two of the most common types of distortion are barrel distortion and pincushion distortion. While people often discuss these in the context of spherical lenses, anamorphic lenses add a new layer of nuance and complexity.
Let’s dive into what barrel and pincushion distortion are, how they affect both spherical and anamorphic lenses, and how an anamorphic lens introduces its own distinctive optical qualities.
Barrel Distortion: The Outward Curve
Barrel distortion occurs when straight lines, especially those near the edges of the frame, curve outward, creating a subtle bulge effect. This distortion looks like the outward bowing of a wine barrel. Wide-angle lenses most often create this effect because of their wide field of view.
Barrel Distortion in Anamorphic Lenses
With anamorphic lenses, barrel distortion often appears more pronounced along the horizontal axis, due to the lens’s squeeze ratio. This distortion enhances the expansive, cinematic feel of anamorphic images. You may notice vertical lines subtly bowing outward during horizontal pans, creating a sense of spatial movement that’s uniquely anamorphic.
Pincushion Distortion: The Inward Pull
Pincushion distortion is the opposite of barrel distortion: straight lines bend inward toward the center of the frame, making the image look like a pin pressing into a cushion. In portrait photography, photographers often value pincushion distortion for its flattering effect, since it can make subjects’ faces appear slimmer.
Pincushion Distortion in Anamorphic Lenses
Pincushion distortion in anamorphic lenses is especially visible near the edges of the frame. It usually appears less pronounced than barrel distortion, and it is not typically associated with anamorphic lenses. You may be surprised to see pronounced barrel distortion in certain manufacturers’ Anamorphic lenses. Anamorphic pincushion distortion contributes to the lens’s unique edge character and edge fall-off.
What causes Pincushion and Barrel distortion in the first place?
In spherical lenses, distortion is most controlled around the 50mm “standard” focal length. As you move to wider focal lengths, barrel distortion becomes more noticeable. For example, a 35mm lens shows a small amount, while a 15mm lens shows very strong barrel distortion. When you go beyond 50mm into telephoto territory, the opposite happens: pincushion distortion begins to appear. It’s usually less pronounced than barrel distortion, but it increases with longer focal lengths. For example, an 85mm lens may show slight pincushion distortion, while a 400mm lens shows it more strongly.
Anamorphic optics add their own unique distortion, but the same principles still apply. Wide anamorphic lenses usually show stronger barrel distortion. Very tight focal lengths often show less barrel distortion or even slight pincushion distortion. Most popular anamorphic designs increase barrel distortion, which many people now associate with the “anamorphic look.”
Blazar MANTIS Distortion Test and Comparison
Check out this short video comparing the distortion across the full 5-lens set of Blazar MANTIS 1.33X Anamorphic lenses
Unique Anamorphic Distortion
Anamorphic lenses extend beyond traditional barrel or pincushion distortion. Although these familiar distortions still affect the image, the lenses’ optical design adds a layer of anamorphic distortion, distinctly influencing the overall image.
- Pincushion & Barrel distortion
Anamorphic lenses don’t all distort the same way. Many anamorphic lenses create barrel distortion, while others create pincushion distortion. Some even show a mix of both, especially certain wide-angle or vintage optical designs. At Blazar, many of our lenses lean toward barrel distortion, echoing the look of classic vintage anamorphics. Lenses like the MANTIS 25mm 1.33X, REMUS 33mm 1.5X, and CATO 40mm 2X deliver a bold, stylized rendering, with strong barrel distortion that enhances the cinematic character of the frame.
- Spatial Compression and Expansion
The squeeze factor of an anamorphic lens compresses the image horizontally, and editors later desqueeze it in post. This process stretches the background vertically when it’s out of focus, often creating oval-shaped bokeh and elongated backgrounds.
- Anamorphic “Mumps” and variable squeeze factor
Some anamorphic lenses do not maintain a consistent squeeze factor throughout the focus range. As a result, objects can subtly change shape depending on the focus distance. This phenomenon, often referred to as “Anamorphic Mumps,” causes subjects in the center of the frame to appear unnaturally wider or thinner, depending on the focus. The effect stems from shifts in the squeeze ratio at varying focus distances. Similar to mumps, some anamorphic lenses exhibit a varying squeeze factor from edge to edge, which does not change with focus distance. This creates a similar effect on the image but is much easier to correct than anamorphic mumps, since it stays consistent regardless of focus. Unlike other forms of anamorphic distortion discussed here, cinematographers generally consider mumps and squeeze-factor irregularities to be optical flaws that need correction.
- Focus Breathing
Focus breathing is the slight zoom in or zoom out that happens when you shift focus. When combined with the natural spatial compression of anamorphic optics, it creates a very distinct and dramatic look when racking focus. This effect, while technically an imperfection, is a big part of the cinematic character that makes anamorphic imagery so unique.
- Field Curvature
Some anamorphic lenses don’t keep a perfectly flat focus plane. When focused on a flat surface, like a brick wall, the center may be sharp while the edges appear soft. This is due to field curvature, where the edges require a slightly different focus distance than the center. In practice, it creates a natural, three-dimensional look with sharpness that gently falls off toward the edges.
Can You Correct These Distortions?
Modern editing software like DaVinci Resolve, Adobe Premiere Pro, Adobe After Effects, and Final Cut Pro provides tools to correct distortion, though some types are much easier to fix than others.
- Pincushion/Barrel Distortion: You can correct these easily by eye or by creating dedicated lens profiles.
- Spatial Compression and Expansion: You cannot correct these in post-production.
- Anamorphic Mumps and Variable Squeeze Factor: You can correct a variable squeeze factor fairly easily using custom desqueeze profiles, as long as it stays consistent regardless of focus. Lenses with anamorphic mumps have a squeeze factor that changes with focus and that requires tedious manual correction.
- Focus Breathing Distortion: Focus breathing changes with focus, but you can correct it by animating the scale to compensate.
- Field Curvature: You cannot correct field curvature in post; you must account for it on set when focusing on objects near the frame edges.
Because of this, many cinematographers choose to embrace these natural distortions as part of a lens’s character. It is often these imperfections that separate digital precision from true optical storytelling. That is why it is important to understand the unique distortions of any lens you use, especially when it comes to anamorphic lenses.
The Blazar Philosophy
At Blazar, we believe in the art of optical design. Our anamorphic lenses are crafted to deliver striking cinematic visuals with a careful balance between precision and personality. Subtle, intentional distortions are part of what gives our lenses their character and immersive feel.
By understanding how different types of distortion influence your frame, you gain more creative control over the mood, texture, and emotional impact of your work.
Explore Blazar Lenses | Affordable Anamorphic for Every Creator
At Blazar Lens, we believe anamorphic storytelling should be accessible to every filmmaker. That’s why we offer high-quality, affordable anamorphic lenses for creators at all levels. With classic characteristics like streaky flares, smooth focus falloff, and gorgeous bokeh, our lenses are built to bring your vision to life.
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