Canon has squeezed 250 megapixels into a camera image sensor -- an impressive number, but not necessarily the one that Canon customers should exult over.
On Monday, the Japanese camera maker announced the image sensor has a resolution of 19,580x12,600 pixels on a chip measuring 29.2 by 20.2mm. That sensor size, called APS-H, is intermediate between the smaller 22.5 by 15mm APS-C sensors on Canon's mainstream SLR cameras, such as the 20.2-megapixel , and the more expensive 36 by 24mm sensors on its premium "full-frame" designs, such as the new 50-megapixel .
The achievement is a notable advance in miniaturization. At the pixel density of Canon's chip, you could fit about 418,000 pixels onto a ballpoint pen tip measuring 1 square millimeter in area.
Why should you care? Because the detailed imagery enabled by high-resolution sensors brings new realism to photography, and today's research projects turn into tomorrow's consumer products. Canon said that on a camera built with the 250-megapixel image sensor, researchers were able to read the lettering on the side of an aircraft flying 11 miles (18 km) away -- though the company didn't say what lens it used to achieve that result.
But Canon photographers -- and there are millions of them -- probably should refrain from thumbing their noses at people using Nikon or Sony cameras. Sony, which supplies image sensors to both those Canon rivals, has been on a tear in recent years. Not only has it surpassed Canon's in-house sensors for most of those years when it comes to resolution, it still has the lead when it comes other important measurements.
Take dynamic range, for example, an important measure of the distance between the brightest brights and the darkest darks. Here, Canon's 5DS has can capture imagery with a dynamic range of 12.4 exposure values, according to rigorous tests by imaging consulting shop DxO Labs. Nikon's D810 far outpaces it at 14.8, and Sony's A7R II is also ahead at 13.9.
Or look at color sensitivity: DxO measures the Canon 5DS at 24.7 bits, the Nikon D810 at 25.7 bits and the Sony A7R II at 26 bits. The Nikon and Sony cameras also outpace Canon when it comes to shooting in low-light conditions.
Canon's new design is more a research project than something destined for an ordinary camera. Canon says it's considering it for tasks like specialized surveillance cameras and measuring instruments requiring ultra-high precision.
But such work typically does trickle down into consumer products. Canon announced a, for example, and this year, the company's Canon 5DS became the current industry leader when it comes to resolution.
Most people today don't have a strong need for resolution of 50 megapixels, much less 250 megapixels. More megapixels means storage space gets swallowed up faster, cameras and smartphones and computers must strain harder to process them, and photos take longer to transfer over a network. Higher resolution can improve images, though: More pixels means people can crop away parts of a photo to concentrate on a particular subject, help make images and video sharper even when shown at lower resolutions and are good when printing poster-size photos.
Canon's new design has other notable features, too. The company said the design is still good in dim lighting -- often a big challenge for sensors with small, densely packed pixels like those in mobile phone cameras.
Canon also said the sensor has a very fast readout speed of 1.25 billion pixels per second. That figure, which means a camera can extract data rapidly so the sensor can begin to capture the next image, is a crucial aspect for shooting fast bursts of images or for shooting video.