Camera technology is, arguably, the most innovative area of smartphone development and has been over the past three or so years. Huge megapixel counts, software bokeh, and long optical zoom capabilities are just some of the innovations to appear over the past few years. It’s the latter that Oppo is working hard to improve even further, having just lifted the lid on a new hybrid zoom periscope lens system.
The new idea takes the fixed focal length of current periscope cameras and makes that switchable, essentially allowing for two different optical zoom levels using a single lens and sensor system. This takes us one step closer to how variable optical zoom works in DSLR and compact cameras. The idea is to improve intermediate zoom quality, which typically relies on digital or hybrid zoom by having more optical points to capture in high quality.
How does it work?
To achieve this, Oppo splits its seven lenses into three groups that work together to adjust focal length. The two groups nearest the sensor move via a 16-bit high-precision driver mechanism to switch between 85mm and 135mm focal lengths with f/3.3 and f/4.4 apertures, respectively. Focal length is based on the distance from the optical center of the lens to the sensor, so moving the lenses changes the focal length. However, their placement has to be very precise to keep focus. The module also has a corresponding auto-focus and image stabilization module.
This is just part of the picture though. Oppo calls this a hybrid system as it incorporates the company’s Fusion software, allowing for multi-focal length image fusion technology, multi-camera field-of-view alignment technology, and super-resolution algorithms to cater to zoom levels between the two focal lengths and beyond. In other words, smart zoom enhancing software is an equally important part.
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The new approach is reminiscent of a couple of ideas we’ve already seen in the industry. Samsung experimented with Dual Aperture as far back as the Galaxy S9 and uses image fusion zoom in its latest flagships. Huawei’s P40 Pro Plus has a 10x periscope camera and 3x telephoto lens for greater flexibility, relying on a hybrid approach to fill in the gaps in between. Oppo informs us that its solution takes up less space than using two individual cameras and can avoid the dreaded large camera bump associated with telephoto lenses thanks to its periscope design.
Speaking of size, the new design is slightly longer than Oppo’s current periscope camera. The thickness is 6.2mm, so it’s definitely not a small module. Oppo is looking to slim down future versions.
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How far does it zoom?
Oppo informs us that its 85mm and 135mm focal lengths roughly equate to 3.3x and 5.4x zooms, respectively. That’s pretty far, but not as long-distance as the 10x periscope designs already on the market. However, through its hybrid software approach, Oppo’s new design extends out to 11x. That’s roughly equivalent to a 280mm focal length.
The picture below gives an example of the level of zoom on offer from 85mm and 135mm focal lengths. It’s a pretty comprehensive range of coverage.
Even so, total zoom distance isn’t really what’s important. 10x and beyond are much further than most consumers will need for all but the rarest of pictures. Instead, the 2x to 5x range is more commonly used and Oppo’s dual solution should ensure much more consistent image quality moving between 2x, 3x, 4x, and 5x than other single or multi-zoom lens systems.
Finally, the hybrid zoom solution utilizes a 16:11 wide image sensor with a 32MP resolution. There’s support for 4:1 pixel binning, a popular technique to improve low-light photography quality. The system also works with video, allowing for full HD capture at long distances.
Sadly, it doesn’t sound like this version will be heading to a smartphone in the immediate future. Oppo intends to develop a more compact structure with more powerful optical zoom functionality in the future. The company hasn’t given a date for when we will see the technology. I’m hoping for sometime in early 2021, but we might be in for a bit of a wait.
Next: Camera zoom explained: How optical, digital, and hybrid zoom work