Since cell phone camera pixels started to move from 500W pixels to 800W pixels, or even higher pixels, some people said that the card camera would die. But the fact is that the card machine that should have died since 2003 is still alive, and the cell phone pixel has also climbed to a new level of 1300W. In fact, are you satisfied with the camera system of your mobile phone?

In my opinion, although mobile phones can compete with card machines in pixels, they can only compete with card machines, but they cannot kill card machines. In recent years, the development of mobile camera system can even be said to be regressive in some aspects. Let's take a good look at what direction this camera system should go.

flash lamp:

A few days ago, a new patent of Google was disclosed.

Eight LED flash lamps XD, in fact, when I saw it, I thought it was a wonderful patent. Yes, what the author is most dissatisfied with is the current flash of mobile phones. In my opinion, it is a beautiful lie that the mobile phone camera with two LED flash lights can promote the good night scene.

The author has always missed the era of feature phones. Sony's K series mobile phones mainly feature camera functions, a 320W Carl Zeiss certified camera and a xenon flash! The xenon flash lamp that the author believes should be inherited is hard to find in the current era of smart phones.

Let's first introduce the difference between LED flash and xenon flash.

LED flash uses LED light-emitting diodes to fill the light of the subject. Because the brightness of LED light-emitting diodes is far lower than the real flash, it can only play the role of "fill the light". LED does not emit light through the electronic jump inside the atom, but by applying voltage to both ends of the PN junction of the LED, so that the PN junction itself forms an energy level, and then the electrons jump on this energy level and generate photons to emit light. The advantages of LED flash are:

1. The stroboscopic speed is faster than any other light source, including xenon flash lamp. It has a very short rise time, ranging from 10ns-100ns. The lighting quality of white LED can even be comparable to that of cold white fluorescent lamp.

2. LED flash has lower power consumption. In flash applications, LEDs can be driven by a pulse current with a very low duty cycle. This makes the current and the light output generated by the current increase significantly during the actual pulse, while still keeping the average current level and power consumption of the LED within its safety rating.

3. The LED flash light can be lit for a long time, so it can be used as a flashlight for mobile phones.

Xenon flash lamp, also known as high intensity discharge gas lamp, is filled with high-pressure inert gas xenon in the quartz tube. Its working principle is that when the shutter is pressed, the shutter feeds back a signal to the CPU, and at the same time, the CPU synchronously outputs a control signal trigger circuit to the triode to flash. Then the triode is turned on, so that the trigger capacitor begins to discharge, and a pulse current is generated on the primary of the transformer. This current can generate a high voltage of nearly 4000v on the secondary of the transformer, which will stimulate the ionization of xenon in the flash lamp and turn on. The electric energy stored on the capacitor is instantly converted into light energy through the discharge of the flash tube to complete a flash.

The advantage of xenon flash lamp is that it can flash much more than LED flash lamp, but it also has some defects. For example, a certain power storage time is required, which may affect continuous shooting. At the same time, it is impossible to keep the LED flash on.

In actual use, the limit distance of single LED flash is 3 meters; Dual LED flash light is 4 meters; The xenon flash lamp starts to fade from 6 meters. In fact, as can be seen from the above technical popularization, LED flash is not a flash, but a small flashlight to provide light compensation, while xenon flash is the real flash. Although LED flash is the mainstream configuration of smart phones at this stage, it is believed that with the market demand, more phones equipped with xenon flash will come out. At that time, the manufacturer will publicize the night view effect again.

metering:

In fact, light metering is something we don't pay much attention to when taking photos, but its impact on the photo effect can be displayed on the mobile phone screen in real time. Fortunately, recently Love to play computer games Several new mobile phones evaluated have made great improvement and progress in the light metering system. stay Unique photography charm Nubia Z5 shooting sample evaluation We found that the metering in the professional mode of ZTE Nubia Z5 is special. In the review post above, we can see the separation of metering and focusing, which is very helpful for the imaging of photos. I also hope this feature can be supported by more manufacturers.

Zoom:

In this regard, the author believes that it is difficult for manufacturers to configure optical zoom for mobile phones. The current optical zoom system is still very thick. It is really fantastic to use it on a slim body with a body thickness of 10mm. However, Nokia 808 can be said to meet this stringent requirement from another aspect. In the horizontal space of the Nokia 808 phone, the pixels are pulled to 4100W pixels, and we focus on PureView technology. In the PureView technology white paper released by Nokia, we can see what this technology is all about. Nokia adopts the trimming of ultra high altitude starting pixels to achieve a lossless digital zoom effect. Because the original pixels are high enough, even if only a small part of the picture center is cut out, there are actually enough pixels for users to use. According to the technical specifications of the Nokia PureView 808, it can achieve 3x still photo zoom and 4x full HD video zoom without loss of image quality. In practical terms, the Nokia 808 can be called invincible in terms of zoom.

And we don't have to go overboard in zoom. In the absence of major updates on the optical zoom architecture at this stage, the optical zoom must be configured on today's thin smart computers, and the thickness must not be controlled. Maybe we should expect Nokia's PureView technology to shine in major manufacturers.

Photosensitive device:

It can be said that the core of the camera system is the photosensitive device. You can check the details Aikepu: composition structure of mobile camera 。 The larger the area of the photosensitive device, the more photons captured, the better the photosensitive performance, and the lower the signal-to-noise ratio. In short, the larger the sensor, the better the picture quality. In the camera industry, the size of the sensor is a big propaganda point. Compare the sizes of our common card machines and smart phones:

The top left is the common sensor for ordinary mobile phones, the middle is the 1/2.3 sensor for ordinary digital cameras, and the bottom right is the 1/1.2 sensor for Nokia 808.

We can easily see that the future smart phone camera system and photosensitive devices must be moving in a larger and larger direction. At that time, we will be able to kill the card machine.

Anti shake:

In the model evaluation before Love Computer, many readers will ask how the night view is and whether it is fuzzy. In this respect, it can be said that the anti shake function determines whether it is fuzzy. The author believes that the anti shake function is very useful in night scene shooting. stay Detailed explanation of optical anti shake of mobile camera There are detailed answers in the article. The lens of the Lumia 920 uses optical anti shake, which is the first similar design used in smart phones. Optical anti shake has long been used in SLR/micro single lens. The basic principles of the two should be much the same, but slightly different. Unfortunately, we have not found the anti shake diagram of 920. Here we use a structural diagram of the optical anti shake of the camera lens to illustrate the anti shake mechanism. In shooting night scenes, the most common problem is blurring. This optical anti shake can achieve a certain degree of compensation. In addition, the anti shake function is also very useful in our daily walking and driving.

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