Rolling vs. Global Shutter Explained – How It Affects Your Footage

Learning how the shutter works can help you create better images. 

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Rolling vs. Global Shutter Explained – How It Affects Your Footage

If you’re passionate about filmmaking or videography, you’ve likely encountered mysterious distortions in your footage—fast-moving objects warped or flickering screens ruining what could be a perfect shot. These issues often stem from the type of shutter your camera uses. In this article, we’ll explore the fundamental differences between rolling shutter and global shutter, how each impacts your footage, and how understanding these concepts can help you achieve more cinematic results. Whether you’re shooting helicopters, fans, or anything in motion, mastering shutter behavior is key to elevating your visual storytelling.

What Is a Shutter and Why Does It Matter?

Every camera, whether it’s a DSLR, mirrorless, or cinema camera, has a shutter. The shutter’s role is to control how long the camera’s sensor is exposed to light. Unlike aperture or ISO, which adjust how much light enters the camera, shutter speed is unique because it directly interacts with time. This interaction with time is what allows you to capture motion in different ways—either freezing it perfectly or creating beautiful motion blur.

 There are two main types of shutters used in modern cameras: mechanical or electronic, and sometimes a combination of both. Regardless of the type, the shutter controls the exposure duration, but how it exposes the sensor can vary drastically, which leads us into the differences between rolling and global shutters.

Rolling Shutter: How It Works and Its Effects

Most cameras today use a rolling shutter. To visualize how a rolling shutter works, imagine an old freight elevator with double doors. When the shutter is ready to expose the sensor, it opens the "doors" from bottom to top, allowing light to hit different parts of the sensor sequentially, not all at once.

Here’s an important detail: lenses project the image upside down onto the sensor. This means while the shutter exposes the sensor from bottom to top, the image itself is captured from top to bottom. When you adjust shutter speed, you’re essentially changing the size of the gap between these two “doors,” controlling how long each part of the sensor is exposed to light.

In practical terms, the rolling shutter scans the sensor line by line, turning rows of pixels on and off sequentially. This scanning happens very quickly, in tiny fractions of a second, but it’s not instantaneous. Because the sensor is read out line by line, the entire image is never captured at the exact same moment.

Rolling Shutter Artifacts: Why Do They Occur?

This line-by-line capture can cause some strange and sometimes frustrating artifacts in your footage. You may have seen examples where fast-moving objects, like helicopter blades or propellers, appear warped or distorted. This happens because by the time the shutter finishes scanning one line of pixels, the object has already moved, so different parts of the object are captured at slightly different times.

One classic example is helicopter blades that seem to freeze or bend unnaturally. This is not a playback error but a direct consequence of how the rolling shutter reads the sensor. Interestingly, these distortions won’t be visible in your camera’s viewfinder or on your monitor while filming—they only appear during playback.

Common Misconceptions: Frame Rate vs. Shutter Speed

Many creators believe that adjusting frame rate can fix rolling shutter issues, but this is a misconception. Rolling shutter artifacts are caused by how the sensor is scanned, not by the frame rate at which the footage is recorded.

To clarify this, let’s consider a test shot using the Sony a7 III. When shooting at 24 frames per second with a very fast shutter speed (1/8000 of a second), the fan blades still appear distorted, similar to the helicopter blades example. This distortion occurs because the rolling shutter is scanning the sensor sequentially, not capturing the entire frame at once.

Aperture Priority

Shutter Priority

As the shutter speed is decreased (meaning the sensor is exposed for a longer period), the fan blades begin to blur and eventually form a smooth, circular motion blur. This blurring effectively hides the rolling shutter distortion because the motion is no longer frozen sharply but blended over time.

How to Choose the Right Shutter Speed

The key takeaway here is that before filming fast-moving objects, you should decide how you want them to appear. If you want sharp, frozen motion, you must use an extremely fast shutter speed—but keep in mind this can result in unnatural-looking footage, such as helicopter blades that don’t appear to spin.

Alternatively, lowering your shutter speed will create natural motion blur which can mask rolling shutter artifacts and produce a more cinematic look. The classic rule of thumb is to set your shutter speed to roughly double your frame rate (for example, 1/48s shutter speed at 24fps) to get pleasing motion blur.

Global Shutter: The Ultimate Solution

Unlike rolling shutter, a global shutter captures the entire image sensor simultaneously. Instead of scanning line by line, a global shutter activates every pixel at the exact same moment, capturing a full frame instantaneously.

When you adjust the shutter speed on a global shutter camera, you’re simply controlling the total exposure time of the entire sensor. This means you can still create motion blur naturally, just like with rolling shutter, but without the distortion artifacts.

Why Aren't Global Shutters More Common?

Given the advantages of global shutters, you might wonder why every camera doesn’t use this technology. The answer lies in the technical challenges and trade-offs:

• Power consumption: Global shutters require significantly more power to operate.
• Heat generation: Capturing and processing the entire sensor data at once generates a lot of heat, which can affect the camera’s performance and lifespan.
• Processing demands: They require faster processors to handle the large amounts of data captured simultaneously.
• Cost and size: To manage heat and power, cameras with global shutters often need additional cooling systems, making them bulkier and more expensive.

Currently, global shutters are mostly found in high-end cameras like the Sony A9, some RED cameras, and select ARRI models. These are typically professional cinema cameras designed for demanding production environments.

Practical Implications: When Do You Really Need a Global Shutter?

For many filmmakers and videographers, rolling shutter artifacts are a common challenge. For example, shooting corporate videos often involves filming computer screens or LED lights, which can produce scanning lines and flicker due to rolling shutter limitations.

Global shutters can solve these specific issues by eliminating distortion and flicker entirely. However, for most everyday shooting scenarios, understanding how to manage shutter speed and motion blur will help you avoid or minimize rolling shutter problems effectively.

Tips to Avoid Rolling Shutter Problems

1. Plan your shots: Think about the motion in your scene and decide if you want to freeze or blur it.
2. Adjust shutter speed: Use slower shutter speeds to create motion blur that hides distortion or very fast shutter speeds to freeze motion, accepting some unnatural artifacts.
3. Avoid extreme fast pans or fast-moving objects: These are the most likely to highlight rolling shutter distortions.
4. Use professional cameras with global shutter technology when necessary: For high-end productions where distortion is unacceptable.

Conclusion: Mastering Shutter for Cinematic Footage

Understanding the mechanics of rolling versus global shutter is essential for any filmmaker or videographer aiming to produce high-quality footage. While rolling shutter technology is prevalent and generally sufficient for most shooting conditions, it comes with inherent limitations that can cause distortion artifacts in fast-moving scenes.

Global shutter technology offers a perfect solution but at a higher cost and complexity, making it less accessible for everyday creators. Until global shutters become more widespread, the best approach is to master shutter speed settings and motion blur techniques to creatively work around rolling shutter issues.

By controlling shutter speed intelligently, you can either freeze motion or embrace motion blur, transforming your footage and avoiding those frustrating artifacts. With this knowledge, you’ll be better equipped to capture stunning, cinematic visuals that captivate your audience.

by Chris Tinard ©️ cNOMADIC 2025
To learn more about cNOMADIC's online cinematography course, visit cNOMADIC.com