Sony Claims New RGBW Sensors Improve Exposure, Low-Light Performance

Sony has announced a new line of image sensors that will, in all likelihood, end up in dozens of smartphone models. The improvement is not in megapixels, which have more or less hit a ceiling, but in the actual layout of the light-sensitive wells that make up the pixels in the image.

The new sensors have, in addition to the usual red, green, and blue-filtered pixels, an unfiltered pixel element as well that will accept any wavelength of light. It can’t be used to determine color, but it will add (they say) to both sensitivity and brightness. Essentially what they’re doing is including a hard luminance-detecting element. This is good, much more accurate than taking the average from the RGB elements, and should in fact make low-light photography significantly better.

The press release shows off an improved low-light shot (seen above) and a video where an “HDR” function is used to reduce blowouts and even out exposure. By decoupling the color from the luminance measurements, more latitude is given to the image processor to create an image within clipping boundaries.

The idea isn’t new; in fact, LCDs already exist that use the image-producing (as opposed to capturing) variant of this. Sharp’s “Quattron” TVs have a fourth, yellow pixel that adds to both brightness and warmth. It’s different, of course, but the principle is similar.

And interestingly, Sony isn’t the first to do this, or at least they are not the first to attempt it: Kodak, the poor dears, were granted a patent for this very thing in 2007. It’s very likely that Sony developed this independently, but may have had to license the technology from Kodak in order to actually sell this type of sensor. Given how aggressively Kodak has been pushing its patents in the last year, the timing seems unlikely to be a coincidence — but it is not stated one way or the other. Sony says, however, that the technology was unfeasible until they designed this new chip around it, which reduces the area needed for a photosite and presumably enables higher pixel density.

Don’t expect any devices to ship with these new RGBW sensors for a while: the first 13-megapixel sensors will be shipping in June, and 8-megapixel ones in August. So phones and cameras using this technology likely won’t be appearing until the end of 2012. Something to look forward to.