Is Thunder made in China? Ask the master to briefly introduce the relevant knowledge.

1:CCD-abbreviation of English charge coupled device, Chinese name is "charge coupled device". What are the characteristics of CCD?

The CCD technology is mature and the imaging quality is good. After all, it is the most widely used imaging element now, but it also has shortcomings:

1) consumes a lot of power. Early digital cameras were known as "electric tigers", and one of the main reasons came from CCD. Although the use of low-energy components such as low-temperature polysilicon display screen reduces the power consumption of the camera to a certain extent, CCD is still a big power consumer of digital cameras-CCD keeps working at any time after the digital camera is turned on, which consumes a lot of electricity unnecessarily.

2) The process is complicated and the cost is high. The complex structure of CCD determines the complexity of its manufacturing process, so so far, only a few electronic giants can produce CCD.

3) pixel promotion is difficult. The first two shortcomings of CCD also directly lead to this shortcoming. There are only two ways to improve CCD pixels: one is to increase the CCD area by keeping the unit area of photosensitive elements unchanged, and integrate more photosensitive elements on a large CCD. However, this method will lead to low yield of CCD, high manufacturing cost and high power consumption, which is unrealistic in the civil field; Second, reduce the unit area of photosensitive elements and integrate more photosensitive elements on the existing horizontal CCD area. However, this method will reduce the unit photosensitive area of photosensitive elements, reduce the overall sensitivity and dynamic range of CCD and affect the image quality.

2. How to understand the basic parameters of imaging elements?

Imaging element is the core of digital camera, so it is necessary to know some important parameters correctly, which will bring a lot of help to understand the basic performance of digital camera and how to buy digital camera.

Total pixels-Total pixels refer to the number of imaging units on the imaging element of a digital camera. A CCD with a total pixel of 5.24 million means that 5.24 million imaging units are integrated on it. The total number of pixels is basically used to mark the performance of digital codes one by one.

Effective pixel-When a digital camera is imaging, the edge of the photosensitive element will be blurred due to the diffraction of light. In order to ensure the imaging quality, this part of the imaging on the photosensitive element will be discarded, so the photosensitive unit cannot use 100%. The utilized pixel, that is, the final image, becomes an effective pixel.

3:CCD size-refers to the diagonal length of the photosensitive element, usually in inches. Common ones are11.8 inch, 1/2.7 inch, 2/3 inch and so on. Generally speaking, the larger the size of the photosensitive element, the better the performance and imaging effect of the element. In addition, the photosensitive elements of digital cameras generally adopt the aspect ratio of 4: 3, especially 3: 2.

4: ISO-refers to the sensitivity of photosensitive elements to light induction. The larger the value, the higher the sensitivity. Common values are 50, 80, 100, 160, 200, 400, etc. At present, the highest ISO value of photosensitive elements of digital cameras can reach 3200. It should be noted that although a high ISO value can improve the imaging quality of a digital camera in a dark environment, the higher the ISO value, the more obvious the impact on the image quality and the more noise there will be.

5. What is the conversion relationship between the print size of digital photos and the resolution of photos?

What is the conversion relationship between the print size of digital photos and the resolution of photos? It can be expressed by an expression:

The number of pixels on the long side of a digital photo ÷ photo output accuracy = the size of the output photo.

Take a 5 megapixel digital camera as an example. The maximum resolution of the output photos is 2560× 1920, and the effective pixels are 2560×1920 = 4915000, which is about 4.92 million. If the print output accuracy is 300 dpi (dpi-dots/inch), you can output 2560÷300=8.5 inches, that is, you can output 8 inches of photos; If the digital photos are developed digitally, according to the minimum printing accuracy of digital printing 150DPI, 2560÷ 150= 17 inches can be output, that is, photos with 17 inches can be output. In other words, a 2-megapixel digital camera can generally achieve a photo resolution of 1600× 1300. If you print digitally with the lowest printing accuracy of 150DPI, you can get a photo of 10 inch, which is enough for ordinary families.

6: What is aperture?

Aperture is a parameter used to express the luminous flux of lens, and it is also an important index to measure the quality of lens. Generally, we use the maximum aperture value of the lens to represent it. Aperture is generally expressed as "F+ number", which is based on the ratio of lens focal length to lens effective aperture, that is, the larger the lens effective aperture, the smaller the value after f, which means the larger the aperture. Generally, the numerical value of the aperture is increasing or decreasing in geometric series, such as F 1, F 1.4, F2.8 A lens with a large aperture is called a fast lens. For example, in a poor light environment, the lens with the maximum aperture of F2.8 needs only a shutter of 1/30 seconds because of its large luminous flux, but the lens with the maximum aperture of F4 can't. So generally speaking, the larger the aperture, the higher the lens quality. In addition, a parameter related to the aperture is the aperture of the lens. The aperture of a lens is the diameter of the lens. The larger the aperture of the lens, the more light it passes, the better the imaging, and of course, the more expensive it is. The aperture is expressed in mm, and the significance of understanding this parameter is that when you want to choose accessories such as UV mirror, color filter or external lens for the lens in the future, you must buy corresponding accessories according to the aperture of the lens.

7: What is digital zoom? What's the difference between it and optical zoom?

Digital zoom, also known as digital zoom, uses the built-in program of digital camera to enlarge the image through software. The traditional camera's ability to take a long-range view depends entirely on the lens, while the digital camera benefits from the advantages of digital imaging technology, which can provide zoom capability higher than the optical zoom multiple of the lens, that is, digital zoom. Digital zoom is to use software to judge the colors around existing pixels and insert pixels added by special algorithm according to the surrounding colors.

Although digital zoom can make the object in the photo bigger, because the photo it produces is obtained by software operation, the quality of the photo it finally obtains is different from that obtained by optical zoom-optical zoom is a real pixel, which can restore the distant scene without any quality loss. So we can say that digital zoom is actually at the expense of photo quality, so in practical use, digital zoom has almost no practical use.

8: White Balance

White balance is a unique concept of digital cameras, which is actually the same as the color temperature mentioned in traditional camera photography. High color temperature will make the whole image blue and cold. On the contrary, the image will be red and warm. When we use a digital camera, we often encounter the problem of color deviation between the captured image and the actual scene. At this time, you need to adjust the white balance of the digital camera. Generally, the white balance of digital cameras will have indoor, outdoor, cloudy and sunny options. There is also an automatic white balance function, but sometimes there is deviation, so manual white balance function is needed.

9: exposure compensation: according to the ambient light, the exposure compensation is increased when it is dark, and decreased when it is not dark! ~

Correct exposure is the technical key to get a good image. Although most cameras have metering and automatic exposure systems, independent hand-held exposure meters are more conducive to measuring ever-changing outdoor light sources. For example, backlight, exposure value is determined according to the shadow. By properly increasing the exposure (increasing 1/2EV to 2EV), people's skin texture can be better expressed and artistic charm can be added. Of course, under normal circumstances, the built-in metering system of SLR can completely occupy this position, but in some cases, it is necessary to avoid false measurement, such as wearing all-black and all-white clothing in a large area of bright or dark background, which can implement positive and negative fill light or partial metering and spot metering on people's faces.

10: shutter speed: in short, it is to control the photosensitive ability of CCD. The slower the shutter, the brighter and darker the photo! ~

1 1: color effect, contrast, saturation: these are the effects of photos. As long as exposure compensation, white balance, ISO sensitivity and shutter speed are properly adjusted, the color effect, contrast and saturation of photos will be reasonably matched. Of course you can Photoshp, even if the effect is worse, you can modify it! ~

I hope your class is helpful to you! ~~~~`