Canon recently released details on its ME20F-SH, a small video camera with a headline-grabbing spec: four million ISO.
Let's put that in context. ISO is a metric used to measure how sensitive film and digital sensors are to light, and four million ISO is astronomically high. For comparison, most other high-end digital cameras these days can hit 100,000. Sony's Alpha a7S—which is known as one of the best low-light cameras on the market—maxes out at 409,600 ISO.
The ME20F-SH, which goes on sale in December, will be capable of shooting color HD video in near-total darkness, thanks to its four million ISO. It's rated to record subjects in as little as 0.0005 lux (lux being a measure of how much an object is illuminated). For reference, a bright summer day can be about 100,000 lux, while an overcast night sky might yield 0.0001 lux.
This is possible in part because of the camera’s pixels—the array of tiny “buckets” on the sensor that collect light and turn it into electrical signals that are processed into an image. As a general rule of thumb, the larger the pixels are, the higher the camera's resulting ISO range.
To get to four million ISO, Canon uses gigantic 19-micron pixels. A micron is a millionth of a meter, and while 19 of them together are still skinnier than a human hair, that’s enormous in the world of digital imaging. One of the ME20F-SH's pixels takes in roughly 10 times the amount of light of a standard-camera pixel, based on surface area, and as much as 160 times as much as a smartphone pixel. Canon goes even further, making sure to point out that the ME20F-SH's pixel area is more than five and a half times larger than in some high-end cameras, including its own EOS-1D X.
"A 19 micron pixel is huge," says Joyce Farrell, executive director of the Stanford Center for Image Systems Engineering. "It's amazing how huge that is."
Wait, you might ask, why then does the ME20F-SH only have a 2.26-megapixel resolution, which is significantly lower than an iPhone 6's? The reason: the pixels are so big on the ME20F-SH that Canon could only squeeze 2.26 million on the full-frame 35mm sensor. But that’s okay, because to achieve HD video resolution you only need about two megapixels.
Canon smartly suggests using the ME20F-SH for nighttime surveillance, and low-light movie production or nature documentaries. Filmmakers who love to shoot in these conditions will be clamoring to use the camera, but they might have to rent instead of buy, due to the $30,000 pricetag.