What is the correspondence between the resolution of the lens and the sensor? How to match the lens to meet the needs of the application and not to waste?

First of all, it should be noted that when a lens is shipped from the factory, a "lens inspection projector" is generally used to inspect the resolution of the lens. The resolution index embodied in the lens inspection projector is expressed in lp/mm, that is, the number of line pairs that can be resolved per millimeter (line pair), but generally lens manufacturers do not explicitly mark this index in the specifications, but rather replace it with a more intuitive 1MP, 2MP or 3MP mark.

Regardless of how the lens images, the Pixel Size of the sensor affects the physical limit of its ultimate recognition resolution, which is called the Nyquist Frequency, and the smallest Line Pairs that the camera can resolve will be exactly twice the Pixel Size. However, the Line Pair happens to have Moiré-effects at the Nyquist Frequency, which means that the actual scene cannot be projected exactly on the middle of the Pixel, causing the limit to be sometimes resolved and sometimes not. At 0.66 times the Nyquist limit, the amplitude can remain largely unchanged regardless of the phase. Therefore, empirically we will take 0.66 * Nyquist Frequency as the practical resolution limit, which is equivalent to using 3 pixel sizes for one black and white transformation (Line Pair), so the correction formula is as follows:

Pixel Size = 1/[3*(lp/mm)] Unit:mm

To sum up the above, the lens with Line Pair as the standard can be converted to pixel size, the sensor also uses pixel size as the standard, in the standard above the two can achieve consistency. Therefore, the following criteria are met

1. The lens and the sensor are properly matched, and the 3 pixel sizes correspond to one black and white conversion (Line Pair).

2. The image circle of the lens can completely cover the sensor.

To achieve the above two points is the best match. The lens or the sensor is too low or too high is not very suitable, it can be used, but may be limited by a certain party, IADIY will choose the most appropriate match for customers to provide the most suitable products to meet customer needs.