16 ms·
Because the CCD chip (aka the sensor that reads the light) can be electronically read, discharged and reset so a shutter (mechanical or otherwise) is completely
by IIAOPSW 7y ago
Because the CCD chip (aka the sensor that reads the light) can be electronically read, discharged and reset so a shutter (mechanical or otherwise) is completely unnecessary.
- brudgers 7y agoThese days, ordinary walk-around digital cameras use CMOS because it's less expensive. CMOS tends to be read line by line. That's why rolling shutter can be an issue when shooting video.
- fsh 7y agoCCDs are always ready line-by-line, while some CMOS (global shutter) read all lines at the same time. However, in CCDs the image charges are physically shifted downwards which causes streaking instead of a rolling shutter effect. There are (very expensive) frame-transfer CCDs which have a second readout sensor that is not light sensitive. This allows quickly shifting the image into this sensor, significantly reducing streaking.
- randomcarbloke 7y agoCMOS are about twice the price of CCD
- fsh 7y agoCCDs have no way to stop collecting light once the keep clean cycle has ended. A shutter is absolutely necessary for exposure times that are significantly shorter than the reasout time (typically a few ms).