We can often see on the PPT released by some mobile phone manufacturers that a certain mobile phone uses a certain type of sensor, and how many μ m (microns) is the width of the unit pixel, so what is this μ m, what does it represent, and what is its role?

On the PPT of various mobile phone manufacturers, if the unit pixel area of the mobile phone camera released is relatively large, it will definitely be dragged out to say, whether Apple, Google or the flagship products of major domestic mobile phone manufacturers, they will almost tell you how large the unit pixel area of the light-sensitive components on their mobile phones is. Why do manufacturers make such efforts to promote the unit pixel area? We can simply understand that when the lens pixel size is the same, the larger the unit pixel area is, the larger the area of the lens's photosensitive element is, and the larger the photosensitive area is, the electromagnetic interference between points will be reduced, and the imaging quality will be correspondingly improved. The conclusion is a classic sentence in the photography circle: the bottom is bigger than the bottom. Similarly, in the case of the same photosensitive area, the smaller the pixel, the larger the area per pixel.

Speaking of this, does it remind people of The New HTC One (M8) on the shore next door? M8's Ultrapixel concept is also to improve the area of unit pixel by combining a large photosensitive area with ultra small pixels, which finally makes this camera reach the amazing level of 2 μ m per unit pixel area. Of course, it is the pixels of the sample that are sacrificed, and the maximum pixels of the sample taken are only 4.3 million pixels, This is a very bold challenge for the 2013 trend smart phones. In fact, this concept is quite good, and Xiao Bian was very optimistic about this technology at that time. However, due to factors such as weak lens coating and optimization, HTC is prone to purple light, lens glare and overall redness. In addition, after Android phones collectively jumped to 13 million pixels or even higher at that time, more people liked to zoom in and compare. So 4.3 million pixels was far from meeting the market demand, and HTC Ultrapixel was finally eliminated from the market.

So how is this μ m calculated? It is the side length of the sensor and the largest pixel of the sample that affect this value. The value of μ m can be roughly obtained by dividing the two values. For example, we know the size of a sensor, which is actually the diagonal of the sensor area, as well as the side length ratio of the sensor. According to Pythagorean theorem, we know that the square of diagonal length=the square of length+the square of width, and then we can calculate the values of length and width according to the proportion. We can divide the length of the sensor by the length of the pixel to get the value of the unit pixel area.

In addition, there is a simpler way to check the data of relevant sensors at multiple points, which can generally be found.

Does that mean that the unit pixel area of the sensor is small, and the shooting effect will be poor? No, no, no, no, let's just talk about it.

Knowing that you like comparison, I chose the iPhone 6S and iPhone 6, which finally upgraded from 8 million pixels to 12 million pixels, for comparison. Because the sensor area of the iPhone 6S has not increased, but only the lens pixels, According to the above explanation, we can know that the unit pixel area of the iPhone 6S is certainly smaller than that of the iPhone 6. In fact, the official document also states that the unit pixel area of iPhone 6 is 1.5 μ m, while that of the new iPhone 6S is 1.22 μ m.

IPhone 6 on the left and iPhone 6S on the right. Yes, 8 million pixels is so small. Click the magnifying glass to view the original image.

(This is a 100% screenshot of the above figure)

Through the comparison of daytime samples, we can see that high pixels have really improved the resolution, and the iPhone 6S has not lost significantly to the iPhone 6 in terms of image quality and dynamic range.

(Similarly, iPhone 6 is on the left and iPhone 6S is on the right.)

How much influence will imaging have in dark environment? Xiao Bian shot a still life at night under the condition that the ambient light is absolutely controllable. At first glance, the imaging of the two is almost the same.

However, all the truth is revealed after 100% magnification. By contrast, although the unit pixel area of the iPhone 6S is smaller than that of the iPhone 6, the iPhone 6S performs better in suppressing noise. However, the texture and color performance of the objects are slightly better than that of the iPhone 6.

However, it seems that even if the area of unit pixel is reduced, good performance can be achieved through proper optimization and adjustment. However, of course, with a larger unit pixel area, it is believed that it will be easier to get a better proof performance, but a larger unit pixel area means larger and thicker light-sensitive components. In today's trend of pursuing thin and portable smart phones, it is also risky to sacrifice the thickness of the phone for better imaging, For example, the Nokia 808 and Lumia 1020 are not recognized by the market, although they have a good reputation in imaging. For mobile photography enthusiasts, of course, the best hope is to ensure enough lens resolution, but at the same time, the unit pixel area is also guaranteed, and the thickness of the body is not too outrageous.