Each time a new, higher-resolution sensor is introduced, there is speculation that we’ve reached
the theoretical limit of what is possible with today’s technology. As pixels get smaller, image quality
suffers. In particular, smaller pixels mean a lower native ISO, and in turn a decrease in low-light
image quality. Small pixels also start to be effected by the diffraction of light as it passes through
the camera’s aperture. Pushing these two constraints to the limit, Canon has created a stunning
250-megapixel sensor prototype that could be used in a DSLR.
It is an APS-H-size sensor, about 80% of the length and width of a full-frame sensor,
and slightly larger than the popular APS-C format. Given its 19,580 x 12,600 pixel resolution,
that means each pixel is about 1.5 microns — almost the same as in an iPhone 6.
So you could imagine the new sensor as an array of 30 perfectly-aligned, very-high-speed smartphone sensors.
It shows its high speed by being able to write out over 1 billion pixels per second, enabling it to
capture 250MP video at 5 fps.
Canon’s feat of using the sensor, coupled with a prototype camera, to read the lettering on an airplane at
something over 11 miles away is quite impressive. However, since it hasn’t disclosed anything about
the camera or lens used, it is a little hard to tell how much of that magic is the sensor.
For example, DARPA’s Argus can perform similarly amazing visual feats using a massive array of
traditional smartphone-quality sensors.
This may be exactly what Lytro and the lightfield photography business needs
Canon used this prototype camera along with the new sensor to read the lettering on an airplane
over 11 miles awayWhile Canon is looking to eventually market the new sensor to specialized audiences
including surveillance, measuring instruments, and industrial equipment, it may also help pave the way
for practical lightfield cameras. The big problem with lightfield products to date, like those from Lytro,
is how much resolution they give up to gain their ability to capture dimensionality and alter focus
in post-production.
Lytro founder Ren Ng has made it clear that the company was built on the premise that sensor resolution
would continue to improve, making that tradeoff more reasonable. Depending on how much of the lightfield
a camera is designed to capture, it can cut the native sensor resolution by anywhere from 10% to 90%.
With a 250MP native resolution, though, even a 90% reduction would yield a very respectable 25MP image.
