Canon develops CMOS sensor that captures video in low light
Japanese camera manufacturer Canon has developed a large sensor chip for shooting video in extremely dim conditions.
The company said its new 35mm CMOS sensor can shoot high-definition video in environments with 0.03 lux of illumination, at which the human eye has difficulty distinguishing objects. The company said it can record stars with a magnitude of 8.5, compared to the magnitude 6 stars that can be detected using traditional low-light CCD sensors.
On a given size of CMOS sensor the only way to increase resolution, the major selling point for cameras, is to reduce the size of individual pixels. But this cuts down on their surface area and the amount of light they can capture, so sensors with higher resolution typically shoot lower quality in low-light situations.
Canon's new sensor achieves its high sensitivity by increasing the size of individual pixels and lowering the overall count. The company said it has about 2 megapixels, about one-tenth the number of its high-end cameras, but each pixel has about 7.5 times the surface area. It also features modified hardware and algorithms to decrease noise in dark environments.
Canon said it has built a test camera for the sensor and is testing it for use in cases where video is often shot with little light.
"The company is looking to such future applications for the new sensor as astronomical and natural observation, support for medical research, and use in surveillance and security equipment," Canon said in a press release.
Canon said it has no firm schedule for when it will commercialize the sensor.
Canon rival Sony last year showed a back-illuminated CMOS sensor intended for better performance in low light and HDR movie making.
A video on Canon's website compares scenes shot with the new chip compared to a traditional EMCCD. Video recorded with the new chip captures far more stars in a night recording session, and does far better in a dark room lit only by burning incense.
EMCCD, or Electron Multiplying CCD, image sensors, can amplify incoming light without adding excessive noise. They are commonly used in fields such as astronomy and biomedical research.