OPPO is working on a periscopic optical zoom with moving parts for smartphones. The zoom lens has a range equivalent to 85-200mm on a full-frame camera. OPPO also shows five-axis image stabilization for smartphones.
OPPO speaks of ‘continuous optical zoom’ and refers to the fact that the 85-200 mm lens is actually a zoom lens with different focal lengths. The Chinese manufacturer uses a periscopic construction for this, where the lens lies flat in the phone and the sensor is at an angle. The light enters the phone through a prism.
Current ‘zoom lenses’ on smartphones are almost always telephoto lenses with a fixed focal length. For example, in marketing terms, manufacturers refer to it as or 5x ‘optical zoom’, if the focal length of that telephoto lens is 5x longer than that of the primary camera.
In comparison, the 85-200mm zoom would provide a maximum of about 8x ‘optical zoom’. The primary camera of phones usually has around an equivalent of a 24mm to 28mm lens. The zoom range of the 85-200 mm is in fact 2.3x, because that is determined by the ratio between the longest and the shortest focal length.
OPPO says it uses a lens construction made of glass and plastic, with ‘ultra-thin aspherical lenses’, which should ensure good image quality. It is not yet known when the zoom lens will come to smartphones. VIVO already showed a concept smartphone with an optical zoom lens last year. With the Xperia 1 III, Sony already has a camera with a telephoto lens that can switch between two focal points, namely 75 and 105 mm.
Five-axis image stabilization
OPPO is also demonstrating its Five-axis OIS technology. That five-axis image stabilization uses the gyroscope to detect movements. Both the lens and the image sensor can move in five axes to compensate for those movements. The optical stabilization of the lens is used for small movements and the sensor shift is also used for larger movements.
OPPO claims that this allows a maximum stabilization angle of 3 degrees, which is three times more than with other image stabilization techniques in smartphones. From the beginning of next year, OPPO will use the technology in smartphones.
New rgbw sensor and rear screen camera
OPPO also shows a new version of an RGBW sensor, a sensor with an extra white subpixel, which should benefit the light sensitivity. OPPO claims that the new sensor generates up to 35 percent less noise. The manufacturer does not say anything about the dimensions of the sensor. The new sensor will come to OPPO phones at the end of this year. Some phone cameras have previously tweaked the pixel layout to boost light sensitivity. For example, Sony sensors in Huawei phones have exchanged the green subpixels for yellow ones. Huawei has been using those sensors for several years. Before that, Huawei already used rgbw sensors, including in its P8 smartphone.
OPPO is also showing off its improved behind-the-screen camera technology, which it announced at the beginning of this month. The manufacturer says it can now make screens with a pixel density of 400ppi in the place where the camera is behind. That’s similar to what Xiaomi and ZTE are claiming with their latest generations of cameras behind the front screen. Due to this high pixel density, the place where the camera is located is less noticeable, because the pixel density is the same as that of the rest of the screen. OPPO showed the new techniques at its Future Imaging event.