In photography, creating sharp, blur-free photos is always the top goal of photographers, whether professional or beginner. One of the important factors that determine photo quality is the device's image stabilization ability. Many people often focus only on the camera body or sensor, but in fact the lens plays an extremely important role, especially when shooting in low light conditions or using long focal lengths. Image Stabilization (IS) technology was born to solve this problem. The following article will help you better understand anti-shake lenses, their operating principles, popular types of technology and the benefits they bring, so you can make the most of them when taking photos and videos.

1. What is an anti-shake lens?

Image Stabilized Lens is a type of lens equipped with vibration reduction technology to help reduce the shaking of the camera handle or the impact from the environment during shooting. When you hold the camera, no matter how firmly you hold it, your hand will always have very small vibrations. These vibrations, if not handled, will cause image blurring, especially noticeable when shooting with slow shutter speeds or using lenses with long focal lengths.

In-lens image stabilization works by sensing movement and moving the lens to compensate for the shake. This keeps the light hitting the sensor more stable, resulting in sharper images, even without a tripod. This is especially useful when shooting in low light, where the shutter speed has to be slowed down to get enough light, or when using telephoto lenses to capture distant subjects.

Inside an anti-shake lens, manufacturers often integrate tiny sensors and motors that control a group of lenses. When the system detects shake, it moves the lens in the opposite direction of the vibration. This technology has helped many photographers confidently shoot handheld in difficult conditions that previously required the use of tripods or other stabilization devices.

2. How anti-shake lenses work

The working principle of anti-shake lenses is based on the accurate and timely detection and compensation of vibration. When you hold the camera, even very small vibrations can cause the frame to be distorted. With telephoto lenses of 200mm or more, the sensitivity to vibration increases many times.

Inside the lens are motion sensors, usually gyroscopes. These sensors continuously track movement along both the horizontal and vertical axes. When the camera is detected shaking in one direction, the control system commands a special lens group to move in the opposite direction.

For example, when you hold the camera and your hand accidentally tilts to the right, the sensor detects this vibration and immediately shifts the lens to the right to compensate. As a result, the light entering the sensor remains stable, avoiding blurring. This mechanism works extremely fast, processing thousands of times per second.

This allows you to reduce the shutter speed by several notches compared to the traditional “1/focal length” rule. Whereas previously you needed a shutter speed of 1/200 second to take a sharp shot at 200mm, now with 3–4 stops of image stabilization, you can shoot at 1/25 second and still get a sharp image. This is a huge improvement, especially useful in low-light photography or when you want to create short exposure effects without a tripod.

3. Two common types of anti-shake lenses

3.1. Optical image stabilization (OIS)

Optical Image Stabilization (OIS) is a popular anti-shake technology and is favored on high-end lenses. OIS works based on hardware, with lens groups moving in multiple directions to compensate for vibrations. This mechanism helps stabilize light as it passes through the lens, so the image reaching the sensor is always accurate and sharp.

Inside the OIS system are motion-detecting sensors and electromagnets that control the lens. When the camera is detected to be shaking in one direction, the lens moves in the opposite direction. The advantage of OIS is that image quality is improved right from the capture step, without the need for post-processing.

OIS technology is especially useful when shooting in low light or using long telephoto lenses. Major camera manufacturers such as Canon, Nikon, Sony, Fujifilm all have their own OIS technologies, such as Canon IS, Nikon VR, Sony OSS. They work on the same principle but the optimization can be different, helping to bring the highest image stabilization efficiency.

3.2. Electronic Image Stabilization (EIS)

Electronic Image Stabilization (EIS) is a software-based method of image stabilization. Instead of moving the lens, EIS compensates for camera shake by moving the image directly on the sensor and through software algorithms.

As light hits the sensor (usually a CCD or CMOS), the EIS system analyzes the frame. If it detects shake, it shifts the captured image in the opposite direction to compensate. This technology is common in smartphones and compact camcorders, where space is limited and moving lens groups like OIS are not available.

EIS has the advantage of being cheaper, easier to implement, and is especially effective with video. However, it has limitations when dealing with excessive shaking or fast-moving subjects. In addition, due to its software-processed nature, EIS can reduce some image quality compared to OIS.

4. Quick comparison of OIS and EIS

In terms of overall performance, OIS is superior in keeping images sharp right out of the box, especially with stills and low-light shots. EIS is popular on mobile devices due to its low cost, compact size, and effectiveness with regular video.

OIS uses hardware for stabilization, while EIS uses software. OIS is a real boon for professional photographers, while EIS is good for general use. Some modern devices even combine the two, offering both OIS and EIS for optimal performance in both photos and videos.

5. Benefits of anti-shake lenses

5.1. Helps take photos in low light conditions

One of the biggest challenges in photography is low light. When the light is low, you often have to slow down your shutter speed to get enough light, which can easily lead to blur. An image stabilization lens allows you to shoot handheld without a tripod, expanding your creative possibilities in a variety of conditions.

5.2. Increase quality when recording video

Videos are more prone to shakiness than stills due to the long recording time. In-lens image stabilization technology helps smooth out the image, reducing the jitter. This is why many vloggers and travel filmmakers always prioritize lenses with image stabilization.

5.3. Telephoto lens support

Long telephoto lenses like 200mm, 400mm or 600mm are extremely sensitive to vibration. Even the slightest movement can cause significant distortion of the frame. Anti-shake technology helps to capture sports, birds or concerts more clearly without the need for a heavy tripod.

5.4. Versatile for street and travel photography

When traveling or shooting on the street, you don't always have the space and time to set up a tripod. An anti-shake lens helps you capture the moment quickly while still maintaining image quality.

6. Cases where anti-shake should and should not be used

You don't always need to turn on image stabilization. When shooting handheld in low light, using a telephoto lens, or shooting video without a gimbal, image stabilization comes in handy.

However, when using a tripod, anti-shake sometimes causes hunting, the anti-shake system automatically tries to compensate even when the camera is still, making the image less sharp. In addition, with extremely fast shutter speeds (like 1/1000 second for sports photography), turning on anti-shake does not bring much benefit. Some genres such as astrophotography should also turn off anti-shake to ensure the accuracy of the light.

7. Anti-shake levels (stop)

Anti-shake lenses are rated by the number of stops that indicate the level of vibration reduction compared to normal shooting.

Standard lenses typically have about 2 stops of image stabilization, which is enough for basic handheld shooting. Mid-range lenses can achieve 3–4 stops, allowing you to slow down your shutter speed to 1/8–1/15 second while still getting sharp images.

High-end lenses like Canon RF, Sony G Master or Nikon Z can achieve 5–6 stops, and when combined with in-body image stabilization (IBIS) can reach up to 7–8 stops. This allows you to shoot short exposures in low light without a tripod, expanding your photographic creativity in many situations.

8. Conclusion

Anti-shake lenses have changed the way photographers work, helping to expand the creative limits that were previously constrained by physical factors. Understanding how they work, distinguishing between OIS and EIS, and knowing when to and when not to turn on anti-shake will help you maximize the power of this technology. In the future, camera manufacturers promise to continue to improve anti-shake technology, combining many different systems to bring an increasingly perfect photography and filming experience. If you are a photography enthusiast, especially shooting in difficult lighting conditions, an anti-shake lens is definitely a worthwhile investment, giving you more confidence on your creative journey.