Yesterday, OmniVision, a manufacturer of image sensors, announced two new 16 megapixel image sensors. Normally, this would go by the wayside with little to no real recognition of their achievement. The thing that sets apart their latest 16 megapixel sensors is that they are touting them as smartphone sensors, not only that, but they claim that the sensors are capable of 4K video at 60 FPS.
These two sensors, the OV16820 and OV16825 are part of OmniVision’s OmniBSI-2 (second generation BSI) sensor family and support images up to 4608 x 3456. They can also do 16 megapixels at 30 FPS while doing 4K at 60FPS. They also feature an 8-lane LVDS/MIPI serial output interface and a strobe output to control flash. The sensors output in 10/12 bit RAW RGB format and have a wide array of programmable controls ranging from gain, exposure, frame rate, image size, horizontal mirror, veritcal flip, cropping, RAW scaling windowing and panning.
The OV16820-C28A is a CLGA mounted 161-pin chip with a package size of 12.8 x 11.8 mm designed to fit in the 1/2.3" optical format similar to the Pentax Q’s sensor. Since the array itself is 4608 x 3456 micrometers and 16 megapixels, the pixel size amounts to 1.34 micrometer the image sensor size is 6.174 mm x 4.631 mm. The RAW RGB output format enables the processor to easily adjust certain parameters like exposure and color depth as well as to quickly capture photos and possibly do some computational photography to create an HDR photo.
While we are extremely excited to see this kind of a camera/video sensor being touted as a 4K product for smartphones, we are extremely skeptical that we will see this kind of technology any time soon. The first barrier to this sensor being used in a smartphone is the fact that the optical format is 1/2.3" As a result of that, it will likely force phone manufacturers to use a 4.3" screen sized device and could possibly have a slight bulge similar to that of the Nokia 808 Pureview to accommodate the sensor and optics. That phone has a 41 megapixel sensor (38 megapixels effective) but really is designed for users to utilize lower resolutions (12 MP and 5 MP) with more color depth and video at only 1080P. This sensor, though, is quite a bit smaller than the Nokia 808 Pureview and in the OV16825 format (not in the 16820 format with the 161-pin 12.8 x 11.8 mm package size) capable of fitting relatively comfortably in a slightly thicker smartphone or one with a little bulge.
Note: 1/2.3" in light purple and Nokia 808 in Peach – Image Credit: Dpreview.com
This brings us to the second barrier, processors. Right now, there are no smartphone processors out there that are capable of handling the bandwidth necessary in order to not only accept 4K footage but to also process it and output it. Currently, most smartphone processors (Apple A5, NVDA Tegra 3, QCOM MSM8960, Samsung Exynos Quad and TI OMAP5432) are only capable of delivering 1080P recording and 1080P playback. Many of them do not have the GPU power nor the bandwidth to and from the GPU (nor the memory bandwidth) to smoothly record and playback 4K video.
Until that happens, there is no way that we will ever see 4K video recording and playback on a smartphone. If there is a company that could get this kind of an image sensor to work, it would have to be someone that has a superior GPU and the memory bandwidth to support it. Currently, we do not see any smartphone SoCs that can deliver on that promise. There will likely have to be a separate chip for image processing in order to actually deliver 4K recording and playback and that would not be very welcome in a world where smartphone processors are converging into a single chip. Especially considering how important battery life has become and the battle for the best performance while maintaining acceptable battery life.