Smartphone manufacturers try to differentiate their devices with the hardware and software of their cameras, although on paper it is sometimes difficult to find the differences.
Instead of looking at the number of cameras and megapixels, look at important details such as the type of stabilization of the main camera. Terms like OIS, EIS or Sensor-Shift may sound similar, but their results are very different.
Why do you need OIS or EIS on your phone?
When your phone’s camera opens the shutter to capture light, a slight movement of the hand can cause the final image to appear blurred. It is more visible when shooting in the dark, as the camera shutter stays open for a long time to capture more light.
You can use a tripod or prop up your phone to stabilize your camera, but it’s awkward and not always an option. This is where a stabilization system comes into play to compensate for hand shake.
Not all stabilization systems are the same. OIS and Sensor-Shift are hardware solutions, while EIS relies on software and CPU/NPU power. Some manufacturers like Huawei have invented the term AIS (artificial image stabilization) to refer to EIS that uses AI.
Optical Image Stabilization (OIS) and Sensor-Shift
A hardware-based stabilization solution uses the phone’s gyroscope and small motors to move the camera lens (OIS) or sensor (Sensor-Shift).
The main camera lens is positioned so that it moves along one or two axes. A high-end camera system has four-two OIS to move the camera lens in all four directions (left/right and up/down).
For example, if you hold the phone and move to the right, the OIS system compensates for the movement by moving the camera lens to the opposite side. It detects movement using a gyroscope and moves the lens using electromagnets and sensors.
Most manufacturers use an OIS system to shift the lens. Apple uses Sensor-Shift to move the sensor on iPhone 12 Pro Max and iPhone 13 series. OIS can move the lens up to 1,000 times per second, while sensor-shift stabilization moves around the sensor up to 5,000 times per second.
Technically, sensor-shift stabilization is better than standard OIS, but don’t expect groundbreaking results.
Electronic Image Stabilization (EIS)
Software-based stabilization dispenses with physical hardware and tries to do the same thing as OIS using software algorithms. The process uses the phone’s accelerometer to detect hand movements and aligns each frame.
EIS takes the image and enlarges it to make it larger than the sensor. If it detects camera movement, EIS shifts the image several pixels in the opposite direction to eliminate blurry shots. Since EIS involves repositioning, stretching, or cropping frames, the results are of lower quality.
EIS is useful when recording videossince in those cases it is usual that you want to move the camera when recording and the use of OIS would compensate for that desired movement.
EIS predicts the direction you are moving while recording video and adjusts the change accordingly. The result is a much more stable video. EIS can use AI to detect the main subject of a video and lock focus. Sometimes it results in an unnatural distortion, often known as a jello effect.
OIS vs. EIS in today’s smartphones
EIS requires no additional hardware, and the camera module remains lightweight and affordable. It is the system that we find mainly in low-end or mid-range smartphones. Implementation is software dependent, and final results may differ from manufacturer to manufacturer.
OIS is an essential element in high end smartphones. Most mid-high or high-end smartphones come with OIS on the main and telephoto cameras. OIS adds more weight and bulk to the camera, and is also more expensive.
Vivo, one of the major manufacturers in China, uses a gimbal camera stabilization system that is complicated, heavy, expensive, and supposedly more effective than traditional OIS systems.
Today, most flagships feature hybrid image stabilization (HIS), which combines OIS and EIS to offer the best stabilization.
