While smartphone cameras do a pretty neat job in most circumstances, their small sensors often fail in extreme conditions, either adding noise to low-light images or blowing out the brightly lit ones. “Dynamic range has been a real problem for smaller sensors in phones. I hope to see [the] new sensor technology improve [the] raw file quality of phone photos and to give more natural tone photos instead of HDR effect,” Finnish professional photographer Mikko Suhonen shared with Lifewire over email.
Layered Approach
In a press release, Sony explained that the current generation of image sensors typically have both their light-sensitive photodiodes, as well as the pixel transistors that control and amplify the signal, adjacent to each other on the same layer. The biggest drawback of this arrangement, especially when used inside a compact form factor like a smartphone, is getting enough light onto their puny little sensors, resulting in poor quality, pixelated images. However, Sony’s new design separates the two, with the photodiodes on the top layer and the pixel transistors below. Sony claims the new layout “approximately doubles [the] saturation signal level” of each pixel, in effect exposing them to twice as much light. Furthermore, Sony adds that moving the pixel transistors to a separate layer frees up space to increase the size of so-called amp transistors. The significance of larger amp transistors is experienced in terms of a notable reduction in noise, which the company argues would be most noticeable in the improved quality of low-light photographs. The benefits of the widened dynamic range and noise reduction should be particularly apparent in high-contrast scenes, such as those with bright lights and dark shadows, which were considered the Achilles’ heel of smartphone cameras. This should allow better optimization for each layer of the sensor and for the sensor to essentially take in more light while outputting less noise. Casual photographers will appreciate being able to take better photos in low-light situations and have less grain in their shots. Portraits, location, and product photographer R Karthik told Lifewire over the phone that the new sensor’s low-light performance would help wedding and sports photographers, though the real beneficiaries would be landscape photographers. “In landscape and location situations, I often time bracket photos to get the full range of light information. This new sensor will save me time usually spent in post-processing in blending exposures,” explained Karthik.
More Bang for the Buck
In addition to all the improvements in image quality, Sony stressed that the new layered structure would “enable pixels to maintain or improve their existing properties” even at smaller pixel sizes. Let’s digress a little to understand the importance of the statement. While it was long rumored that Sony had built a 1-inch image sensor for smartphones, when it finally materialized inside the recently launched successor to the Xperia Pro, the Xperia Pro-I, Sony could only use a 12MP crop from this large 20MP sensor due to internal space constraints. Using the new arrangement, Sony will, at least in theory, be able to get all the image improvements without any significant increase to the size of the chip itself. “This is a pretty big leap in image sensor tech,” summed up wedding and event photographer Ian Sanderson on Twitter. Sony is the image sensor market share leader, and given the apparent advantages of the new stacked chip, it isn’t surprising that the company has promised to use it, at least initially, to boost the quality of “smartphone photographs.” Karthik, too, believes that’s the right move for Sony since professional photographers are adept at navigating around the limitations of their equipment. In his opinion, the new stacked sensor would be a “game-changer” for people whose primary shooter is the one in their smartphone. “Some of these announcements by camera manufacturers can end up being more marketing hype than real, substantive improvements to imaging technology, but I don’t think that’s the case here,” concluded Brandon Ballweg, the owner of the photo tutorial site, ComposeClick, in an email to Lifewire. “I think this is going to be a significant step forward that will benefit pro photographers and casual smartphone users alike.”
