Mobile camera tech has really taken off recently, thanks to the introduction of advanced technologies, like OIS, color sensors, laser auto focus and PDAF. But, this technological leap can easily be overlooked by the average user, simply due to lack of understanding. Qualcomm has realized the need for more palatable explanations of recent advancements and has put out a short, upbeat video with a quick overview of how current Snapdragon chips achieve camera focus.
The technology in the company’s current SoCs is dubbed – “hybrid auto focus”, simply because it features intelligent algorithms for switching between laser and phase detection focus and for using them in tandem. There is nothing really hard to understand about both technologies, once you get a proper explanation.
Snapdragon hybrid auto focus combines these auto focus technologies with smart algorithms developed by our in-house engineers. The processor can intelligently switch between, or use these auto focus technologies simultaneously, depending on the lighting situation. In other words, you can enjoy using your smartphone with Snapdragon processors to take photos virtually anytime, anywhere and feel confident knowing your Snapdragon hybrid auto focus is engineered to give you the perfect focus.
Focusing a photo is all about knowing or rather finding out the precise distance to the object you are shooting, so you can adjust the camera lens accordingly. You have most-probably noticed phones coping with the process in a more-traditional, “brute-force” manner. If there is no special tech to measure the distance, the phone simply goes through every position of the camera lenses in one quick swoop, constantly analyzing the achieved focus and then returns to the best possible setting. This is usually effective, but far from efficient and at times quite slow. In come dedicated focus technologies.
On the one hand, there is Phase Detection Auto Focus (PDAF). It works in much the same way our eyes do. The camera sensor uses a pair of pixels that are a certain distance apart. This makes them view objects out of phase. Calculating exactly how misaligned the view is, is then used to judge the distance to the object and focus. This technique works pretty well with good lighting, but falls short for darker shots.
This is where laser auto focus comes in. It’s method of operation is also pretty straight-forward. A laser beam is shot at the object and then detected once it bounces off, back into the sensor. The time it took the beam to travel to the point we want to focus and back is then used to calculate the exact distance to it, using elementary math. The technique is simple enough, but also quite powerful and versatile. The same principle is actually used to measure the distance between the Earth and the Moon, by shooting lasers at special reflectors, left behind by the lunar landing mission.
Simple enough and yet quite clever, especially since it is all bundled up in tiny the Snapdragon chip, powering your mobile device.