How to test the CCD when buying a digital camera?

The difference between a CCD camera and a digital camera

1. Chips: CCD cameras are charge-coupled devices using CCD chips, CMOS is complementary metal oxide semiconductors using CMOS chips, and the latter is relatively low in cost.

2. Shutter: CCD chip mode is generally frame (global shutter), CMOS chip mode is generally rolling shutter.

3. Imaging: CCD camera is suitable for shooting stationary or moving objects, with good color reproduction, large dynamic range of the chip, good sensitivity, and the dependence of the imaging effect on external lighting is lower than that of the CMOS chip.

The CMOS camera is more suitable for shooting still objects, and the moving object has dragging, and the image will be distorted, the color reproduction is poor, the dynamic range of the chip is small, and the sensitivity is poor, but in the case of sufficient light, it can also achieve better image results.

The above content refers to Encyclopedia - Digital Camera.

3 All CCD cameras refer to:

CCD camera is a safety system, the generation of images is mainly from CCD camera, CCD is the abbreviation of charge-coupled device, it can turn light into charge and store and transfer the charge, and can also take out the stored charge to change the voltage.

Therefore, it is an ideal CCD camera component, and is widely used because of its small size, light weight, not affected by magnetic field, and anti-vibration and impact characteristics.

Application of the principle of CCD camera:

After the image is imaged on the surface of the capacitance array through a lens, a charge of varying strength is formed on each capacitance unit according to its brightness. Linear CCDs used for fax machines or scanners capture a thin strip of light and shadow at a time, while planar CCDs used by digital cameras or camcorders capture an entire image at a time, or a square area from it.

Once the action is completed, the control circuit will transfer the charge on the capacitive cell to the next adjacent cell, and when it reaches the last cell at the edge, the electrical signal is passed to the amplifier and converted into potential.

This is repeated until the entire image is converted to potential, sampled, digitized, and stored in memory. Stored images can be transferred to a printer, storage device, or display. In the early 1990s, frozen CCDs were also widely used in astrophotography and night vision devices, and major observatories continued to develop high-resolution CCDs to capture extremely high-resolution objects**.

CCDs have a wonderful application in astronomy, allowing fixed telescopes to function like tracking telescopes. By making the direction of the charge reading and moving on the CCD be consistent with the direction of the celestial body, and the speed is also synchronized, the CCD guide star can not only effectively correct the tracking error, but also enable the telescope to record a larger field of view than the original.