Camera purchase skills: five guidelines to ensure product quality

At present, computers have become an indispensable part of our lives. In order to improve the functions of computers, various manufacturers have also continuously researched and produced peripheral items of computers, such as printers, scanners and other peripherals and digital products. Attention and favor. Digital cameras are the fastest among them.

Today, with the popularity of broadband networks, we can see friends who are far away from the horizon by using the camera, and they really have the feeling of "the neighbor is beyond the horizon". However, many friends don't know much about cameras, so how to buy a camera that suits you?

Five guidelines for choosing a camera

Usually, a series of technical parameters, such as the maximum resolution and focus range, can be seen on the camera product packaging box, so what should we pay attention to?

1. Photoreceptor

This is the heart of the camera, the important thing can't be more important. General cameras can be divided into two types. One is CCD. Only high-end cameras use this type of photoreceptor. It has the advantages of high sensitivity, anti-vibration, small size, etc., but the price is also relatively high. The second is CMOS. It has the characteristics of low power consumption and low cost, but the resolution, dynamic range and noise are unsatisfactory. In general, CCD imaging level and quality are higher than CMOS. When we recommend high-end users to purchase, we should first consider the products using CCD sensor, of course, you need to pay a little more for the price.

Second, pixels

Pixel value is also an important factor to distinguish a camera from good or bad. Early digital cameras were basically 100,000-pixel products, because the technical level is relatively low, and it is already a eliminated product. Most mainstream products in the market are currently around 300,000 pixels. With the support of such large pixels, the camera can often fill the full screen (640 × 480) when working, and it has a unique advantage when intercepting a single picture.

3. Imaging speed and number of frames

Because the camera is used for online chat, it is also important to have a fast imaging speed, and the imaging speed depends on the overall configuration of the camera, so not only the lens, but the configuration of other components of the camera also determine the quality of the camera. The main part of the camera structure except the lens is the sensor, data processor and peripheral circuits.

If the overall configuration uses inferior accessories, the lens will not be as good as the imaging effect, because it involves the quality of components and the reasonable design of peripheral circuits, but users often ignore this link, usually blindly seeking the lowest price And ignore the overall performance.

Another factor related to the imaging speed is the number of frames. The number of frames is the number of frames for transmitting pictures in 1 second. It can also be understood that the graphics processor can refresh several times per second, usually expressed in fps. Different pictures require different capture capabilities. The maximum resolution of mainstream digital cameras to capture pictures is 640 × 480. However, at this resolution, the picture will jump, and the 30fps capture effect cannot be achieved.

When the resolution is 320 × 240, it is possible to achieve the standard rate capture index by relying on the combination of hardware and software, so the complete video capture speed is only a theoretical index. For frame rate, you can use a book to shake up and down in front of the camera (do not swing too fast) to see if the image delay is serious? If the image can be displayed continuously, it can basically reach the level of 30FPS.

Four, focusing function is indispensable

Some users only found the image very blurry after buying the camera back, but it was good when they tried it at the merchant. Why is this happening? It is usually caused by not adjusting the focus. Like a point-and-shoot camera, the camera uses a super-focus, which has a large depth of field but should be manually adjusted when macro. Therefore, sometimes it is necessary to manually adjust the focal length of the camera to get the clearest image.

However, the focal length of many cheap cameras is fixed, that is, the camera can only capture a clear image at a fixed distance. Once it is too close or too far, it can not get a clear image. The camera lens of good quality can be manually adjusted to focus, so no matter where you put the camera, you can get a clear image by adjusting the focal length, usually we can use the adjustment device that can adjust the lens outside.

The focusing effect is often measured by the focus range. The focus range refers to the range from the closest point to the farthest point where the camera can focus. For example, the focus range of some cameras is 20cm to infinity, which means that the closest focusing distance is 20cm, and the range within 20cm cannot be focused. Even if it can focus, the resulting image is not clear.

Five, data transmission interface

At present, USB has become the standard interface of the camera. This connection method is easy to use and supports hot swapping. The device uses its own reserved interruption alone and does not compete with other devices for PC resources. For cameras with a level of 350,000 pixels, the transmission rate of the USB1.1 interface can fully meet the needs. If you choose a megapixel camera, it is best to choose the USB2.0 interface. However, if you use it on the Internet with this type of product, the display effect on the network is basically no different from the USB 1.1 product due to the speed of the network.

In addition, the factors that users can consider when buying a camera include the accompanying software, built-in microphone, angle adjustment, base fixing device, static shooting, etc., which can bring us a lot of convenience in use. Among them, the application that comes with the camera is an important part. Many manufacturers have included some applications such as image e-mail software and simple video editing software, so that users can choose according to their own circumstances. "

In addition, some image effect correction and enhancement programs are also very practical. For example, adjust the camera's color saturation, contrast, edge enhancement, gamma value, etc., as long as the adjustment is appropriate, sometimes the shooting effect can be greatly improved.