Microsoft’s new curved sensors promise dramatic improvement for compact cameras

 

 

If you take a look at your camera, be it a traditional one or the one in your cell phone, you'll notice that its sensor is flat. This is and has been the design choice for sensors since the beginning of the digital age, but Microsoft has developed a new take on the sensor that they think will dramatically improve image quality... so much so that even small sensors can have the quality we are used to seeing in large sensors. The main difference is that it is curved, and this curve helps the sensor better correct for aberrations and make it much easier to create wide angle leses that produce sharp images across the entire field of view. 

“Our approach to curving commercially available image sensors could make it possible to have a new class of camera that would be very small, but have image quality that would be comparable to image sensors found in much larger cameras,” said Brian Guenter, leader of the Microsoft Research team. “In addition to improving consumer cameras, curved sensors could be used to create better cameras for surveillance, head-mounted displays and advancements in autonomous vehicle navigation.

In The Optical Society journal Optics Express, researchers from Microsoft Research and research-and-development laboratory HRL Laboratories LLC have been able to incorporate a curved sensor into a prototype camera that, when compared to modern SLR cameras, was able to produce higher resolution images across the entire field of view. The researchers state that the benefits of curving a sensor have been known for some time, it is only recently that actually producing such a sensor has been possible. 

In their tests, the researchers found that curving the sensors did not change any of their electrical or imaging characteristsics, and when used in a prototype camera with a specially designed f/1.2 lens, the curved sensor exhibited a resolution more than double that of a high-end SLR camera with a similar lens. Furthermore, toward the edges of the image, the curved sensor was about five times sharper than the SLR counterpart. 

 

Image captured with the curved sensor prototype camera. The zoomed-in portion shows excellent sharpness far from center. The large depth range in the scene illustrates pleasing shallow depth of field enabled by the wide aperture of the f/1.2 lens.

Though the sensor they created for testing was about the size of a small consumer camera, the team believes that the tech could be even further miniaturized so that it could be used in cell phone cameras. They also believe that machines could be built to mass produce the lenses, which would allow the economies of scale to lower their price and increase their availability to the masses. The team is now working to see if they can produce sensors with even more curvature, and experiment with curving sensors that operate in infrared (which could see use in telescopes, 3D spatial mapping, biometric authentification, and other various scientific applications). They admit that they don't see the tech being introduced in commercial products in the short term, but they are interested in figuring out a way to improve the sensor technology and perform the kinds of rigorous testing that would be needed to prepare them for mass production. 

As a note, this type of sensor is best fit for tablets and cell phones (as mentioned, the researchers want to work to make them viable in this application), with the possible use in larger consumer cameras unlikely (larger even including the typical point-and-shoot). According to the results, the only way the curved sensor outperforms the larger SLR is in uniformity of illumination with a 50mm equivalent f/1.2 lens. This is highly specific, and as such it is unlikely that we will see this tech moved into anything other than fixed-lens small sensor cameras (like what you see in tablets and smart phones) at this juncture. A curved-sensor interchangeable lens camera would require a whole new set of optics to be developed to work specifically for it, which is a rather steep hill to climb and a big ask for any major company. Still, the tech is a big advancement for small cameras, and if it can be successfully further miniaturized, its application in cell phones and similar devices would greatly improve mobile photography quality for the masses. 

For more on the curved sensors, you can read the whole report here and the summation of the project at OSA.org. 

h/t Petapixel