Sony's new Exmor RS stacked CMOS sensor adds high-speed AF
Sony has announced the latest iteration of its Exmor RS stacked CMOS imaging sensors. The 21-megapixel IMX230, which will start shipping next year, could improve the photographic capabilities of your next smartphone as it builds on previous models by adding high-speed phase detection autofocus and improved HDR imaging.
As with previous Exmor RS sensors, which are featured in devices from Sony and other manufacturers, the Exmor RS IMX230 employs a stacked structure. Its back-illuminated pixel section is stacked on top of a chip consisting of signal processing circuits. This differentiates it from most sensors which require a support substrate, and allows it to deliver improved image quality and functionality in a compact size.
The main upgrade is that the new type 1/2.4 sensor (7.487 mm diagonal) incorporates an onboard image plane phase detection AF signal processing function. This high-speed system works like those used in mirrorless interchangeable-lens cameras, and can use 192 AF points to calculate distance to the subject and lens position for focusing, which should help when shooting fast-moving subjects.
The HDR imaging sample from the Sony Exmor RS IMX230 (right) shows its improved performance over the IMX135
The new sensor also features improved HDR capabilities and is capable of capturing backgrounds and subjects clearly, even in high-contrast scenes. While this function was previously only possible when shooting video, the Exmor RS IMX230 can also do this when shooting stills.
Sony is not just putting the increased 5344 x 4016 pixel resolution of the Exmor RS IMX230 to good use for stills. The resolution means the sensor can deliver 4K (4096 x 2160) video footage at 30 fps, Full HD 1080p video at 60 fps, and HD 720p footage at 120 fps for creating slow-motion videos.
Like previous Exmor RS sensors, the IMX230 will not be limited to whatever Sony products the firm plans to use it in. It will also start shipping to other manufacturers in April 2015, at a cost of 2,100 Yen (US$18). A 16-megapixel version of the new sensor is also in the works.