What is the shutter
The camera shutter is used to control the effective exposure time of the photosensitive means. Is an important part of the camera, its structure, form and function is an important factor to measure the quality of the camera.
What is Global Shutter (Total Shutter)?
By exposing the entire scene at the same time achieved. Sensor light while collecting all the pixels, simultaneous exposure. I.e., when the start of the exposure, the Sensor start collecting light; at the end of the exposure time, the light collecting circuit is broken. Sensor value that is then read out a photograph. CCD is the Global shutter work. All cells are exposed simultaneously.
What is Rolling Shutter?
Global shutter and different, which is exposed through the Sensor progressive way to achieve. When the start of exposure, the Sensor progressive scan exposure line by line, until all pixels are exposed. Of course, all the action is completed within a very short period of time. Different rows of pixels of different exposure times.
Shortcoming
Global shutter exposure time is shorter, but will increase the read noise;
For camera manufacturers, Rolling shutter can achieve higher frame rate, but when the object moves faster or improper exposure, there will be partially exposed (partial exposure), the ramp pattern (skew), shaking (wobble) and so on. Rolling shutter shooting this way phenomenon, is defined as jelly effect.
When the short exposure time applications (e.g., <500μs) for Global shutter, the exposure time is long (e.g., greater than 500μs), select the rolling shutter can lower noise and frame rate.
Compared
Rolling Shutter defects example
Example 1
Look at the picture below. Imagine each pixel is an orange box, our image only three pixels. When our hero climbed the stairs, a pixel is read once, resulting in one of the last lag.
Example 2
Example 3
