CCD Vs CMOS - Difference And Comparison - Diffen

A CMOS image sensor inside a camera

Shutter Differences - Global vs. Rolling Shutter

CCDs use a global shutter, which exposes the entire image simultaneously. This can lead to blur if any motion occurs in the image during exposure, but a high shutter speed prevents this problem.

CMOS sensors are equipped with “rolling shutters,” which expose different parts of the frame at different points in time. This can lead to skew, wobble and partial exposure in photographs.

In well-lit conditions, the differences in shutter mechanisms do not cause any problems. However, in low-light areas, or under slow-flickering lights, a dark bar may appear rolling through your footage (in case of video recording) with a CMOS sensor. Another risk is the picture may appear split into a dark and bright half when using a flash.

Vertical Smear

CCD sensors are more susceptible to vertical smear from bright light when the sensor becomes overloaded, while high-end CMOS sensors do not suffer from this problem.

A CCD sensor on a circuit board.

Performance of CMOS vs CCD sensors

CCD sensors create high quality images with low noise (grain). They are more sensitive to light. However, CCD sensors consume around 100 times more power than equivalent CMOS sensors.

CMOS images tend to have more noise and need more light to create images at the proper exposure. However, CMOS sensors are much more power efficient, leading to longer battery life, and as they are moving closer to CCD in quality over time.

How to choose

CCDs are preferable when you want to focus on high-quality images with many pixels and need excellent light sensitivity. CMOS sensors are preferable for high speed cameras, as they scan and offload their footage quicker.

Reliability

Although CCD used to be more reliable than CMOS, there is currently no difference between the two sensor types in terms of reliability.

Popular Cameras

CMOS cameras are more popular — only two of the top 15 best selling cameras on Amazon use CCD sensors.

References

• wikipedia:Image sensor
• How image sensors work
• Sensor Artifacts and CMOS Rolling Shutter
• CCD and CMOS for professional video recording - B&H