Since ROCWARE officially released the RC08 Mini full HD USB audio and video integrated camera, and its TOF laser-assisted autofocus system has attracted a lot of attention. Many friends have such questions: Is it necessary to carry a TOF laser-assisted focusing system that is only available in high-end mobile phones for a mini USB Webcam. Is this a gimmick?
To explain this, first we need to briefly understand the three common methods of auto focus in the industry: Phase Detection Auto Focus, Contrast Detection Auto Focus and laser focus.
The full name of PDAF is Phase Detection Auto Focus. The phase focus technology is generally used by SLR cameras, and its entire system structure is relatively complex. Two separate lenses are used to form two images on the sensor, and then the distance between the two images is detected by the linear sensor to determine the focus of current position is in the front or behind, so that to achieve focus quickly.
When the picture is the most clear state, the contrast value reaches the maximum, but the focusing system does not know that it is in focus at this time, so the focusing system will continue to move the lens to focus. When the contrast starts to drop, the focusing system senses that it missed the focus and returns the focus to the position with the highest contrast. So if you have a camera with contrast focus and you're in autofocus, you can see that there's a blur - clear - blur - clear process.
Contrast focus makes focusing very precise, but a bit slow. Both phase focus and contrast focus are more dependent on the external light perception, so the requirements for ambient light are higher. If the ambient light is low, it will also slow down the focus speed. Thus, the laser autofocus mode appeared.
Laser focus is to send low-power infrared laser to the object being photographed through the infrared laser sensor next to the lens, and then calculate the distance of the object being photographed by recording the time difference between the infrared laser emission from the sensor then reflected by the target surface, and finally received by the sensor, so as to complete focusing. This way of focusing is very fast and does not rely on reflected light, so it can still ensure excellent focusing performance in low light environment. However, due to the focusing distance and cost, the use of laser focus is still limited.
After a brief understanding of the three AF modes, let's take a look at the AF mode of RC08. RC08 adopts TOF laser-assisted autofocus system, which is actually a combined focusing mode of contrast focus and laser focus. Combining the advantages of precise contrast focus and fast laser focus to achieves the effect of 1+1 > 2 through self-developed algorithm.
When RC08 performs autofocus, contrast focus and TOF laser-assisted autofocus work at the same time. TOF laser-assisted autofocus will use the distance between the image obtained by the lens and the object obtained by the sensor, and calculate the depth of field information and distance of the subject according to a certain algorithm, and then combine this data with the data obtained by the contrast focus to quickly find the focus to complete the focusing. Therefore, the focusing speed of RC08 is faster than the contrast focus used by traditional cameras.
At this point, I believe you have understood that the TOF laser-assisted AF mode of the RC08 is not a gimmick, but a practical technology that can really solve the problem.
So the question is again, what obvious benefits can RC08 bring to remote video collaboration or live streaming?
Follow us for answers in the next post.