You might have come across terms like OIS and EIS when you are searching for good camera phone. This significantly improves the quality and video. Now its time to distinguish this terms so next time you buy a phone you will know what does this feature mean.
Optical image stabilization (OIS)
In this technique the image is stabilized by varying the optical path of the sensor. This is real time compensation and hence no alteration or image degradation takes place. The lens assembly is moved parallel to the image plane. Gyroscope is used, which transmit this information to a microcomputer which in turn converts them into the Drive signal which ultimately moves the lens Assembly to correct the image project on the sensor before it is converted to digital format and thus off-sets your motion. This is the basic principle of all OIS techniques. Different companies have different names for their OIS Technology eg. PureView by Nokia, Ultrapixel by HTC, etc. Nokia made the first cell phone optical stabilized sensor built into Nokia Lumia 920. OIS is more popular in consumer camera devices because it works efficiently even in poor lighting conditions and you wont see degradation in image resolution as corrections are made prior to the signal conversion in digital format.
Electronic image stabilization (EIS)
Electronic image stabilization works on a completely different principle and in this technique the problem is solved at programming level after the optical signal has been converted to a digital signal.
Every camera has a Charge Coupled Device popularly known as CCD which is an array of several light sensors arranged in a grid. It captures the optical light and transmits the image for processing in the form of digital signals.
In EIS the processor breaks down the image in to small chunks and then compares it to the preceding frames. It determines whether the motion was a moving object or an unwanted shake and makes the required correction. Now when you shift the image you need to fill in the shifted area and for that you need to have a bigger CCD or provide some area in the existing CCD to capture image for off screen purposes. This might lead to image degradation; however the effect is fairy less when your camera device has fairly large resolution.
So which is better, OIS or EIS?
Main advantage of OIS is that there is no image degradation as necessary compensations are made before optical signal is fed to the CCD. But the hardware for mechanical motion of lenses buts a strain on your battery backup and also adds to the weight of the device.
EIS has become quite popular these days because of they are light and less expensive and with improvement in algorithms used for stabilization image degradation is minimal. But at low resolutions and in poor lighting conditions, you might see significant degradation.
With consumer electronic devices which don’t have a very high resolution , like your Smartphone’s or low resolution Camcorders, OIS is more effective technique and also out performs EIS in dimly lit areas.
The recent launch of OnePlus 5 drew a lot of criticism for its camera. It adopted EIS technology and as a result the picture was not up-to the mark, but video quality is great. However a normal smartphone user will hardly notice these effects. It’s really hard to distinguish OIS and EIS if your knowledge about camera is limited. Manufacturers are striving hard to make camera even better. As far as OnePlus 5 camera is concerned, an update can fix the EIS algorithm.
EIS and OIS have very different goals, so you can’t compare them to ask which is better/worse. OIS primarily improves low light photography by physically compensating for hand shake within each single frame, and EIS improves shaky video by maintaining a consistent framing between multiple video frames. OIS is primarily for photo, and EIS is only for video.
Where OIS helps is still low-light photos. It compensates for hand shake, allowing longer exposures in low light, but this in turn increases motion blur within the frame. And it comes with all kinds of tradeoffs, starting off with its physical size.