Wednesday, December 29, 2010

【 Weak current College 】 buy digital camera should note 】

Buying a digital camera, the best advice is: take it easy, don't worry. Do not watch it at a discount to buy, this is important because discounted goods are often outdated, or will be updated instead of more advanced technology.

When you purchase a digital camera, take note of the following:
Buying a camera, it was actually buying a "negative". Resolution camera built-in fixed, not maximum resolution in sensor on the basis of increased. If the image detail is important to you, then select camera, paying particular attention to the maximum resolution of the camera.

Most prices relatively moderate digital camera as a fool, not like SLR cameras that can be user control features. This means that you can only hope that manufacturers in an established price down to the camera configuration to the broadest possible range of control devices. And Pns cameras, optical accessories or other accessories not many. Some digital cameras and 35mmSLR camera is similar, but the prices are very high, so they are only suitable for professional photography.

In a Word, you must be careful to determine what your own image, and purchase the most suited to your needs with the camera.

Finally, a digital camera needs to be saved in memory of photo storage. In order to achieve a more reasonable price/performance ratio, a digital camera usually compress images in various ways. Effects of compression on the image quality is high, some compression system requires the adoption of clear image detail and color information for the relatively small size of the image. This is a direct result of the filmed image sensor has weakened. But at present there are very few cameras store images in the compresses, additional information is not lost.

1. the sensor (CCD, CMOS)
Digital camera resolution not less than 1024X768, so you can catch more image details. Digital cameras use two basic types of image sensors: CCD and CMOS.

CCD camera prices are more expensive, most likely in the coming years it is in the position of inexpensive cameras are CMOS technology. CMOS cameras are currently has just been listed. One thing to be careful: do not use interpolation resolution and confuse the actual resolution.

2. metering system
Exposure table, also known as the camera light meter, in occupies a very important position, as it should, according to the shooting scene to set the shutter speed and aperture.

Best metering system is the "zone metering" or "multi zone metering." In these systems, the camera will capture image is divided into several zones, each zone consists of a camera metering system for estimating separately. Then put the results together, using a special calculation method to determine the best exposure. Then under the metering system-provided information to determine your camera's Aperture and shutter speed. At present, with many regional metering of digital camera is not very much, but this situation is gradually changing.

Today, most digital cameras use a central focus of average metering. This metering focused on Center, and then and the entire screen of metering average values to determine the ultimate exposure. This means that the camera at the darker object, the image of the remaining parts will be overexposed, conversely, too. View the camera's exposure only way is to type a try. Thankfully, most digital cameras in use, you can browse to the image on the LCD screen, the camera metering mode.

Finally, remember: overexposed image areas do not have any available data for future use image editing software can not be recovered.

3. lens
Most digital cameras are equipped with a wide angle lens, equivalent to 35mm camera 30 to 40 mm range. Shoot in this focal length, image distortion occurs, especially in the vertical direction. For this reason, most users still prefer aspherical lens. In addition, with automatic focus, high quality glass lens to any camera is important, especially in macro mode. There are also people who believe that fixed focal length lenses with more easy shooting, but when it's close to the subject object constraints is relatively large.

The lens is also very important. The lens of "F" the number, the small bright (F2.0, F2.8). Lens "F," the higher the value, the maximum aperture is smaller, so it can only make a small amount of light reaching the sensor, the shutter speed is reduced. A lower shutter speed means an image easily blurred shots, especially when photographing and filming is vertical when you move an object.

Finally, note the lens cover is not very easy. Preferably in the lens cap on the lens can be strings, so that the lens cap strap is not easy to lose. Do not look down on such a small lens cap, usually the original manufacturer's product are expensive to be true, so you'd better be careful. Whether you believe it or not, some fairly expensive camera lens was not conspiracy, if you buy this camera, you have to always be careful not to put the lens cap to lose, or you can own the lens cap on wearing a hole, JI on a piece of string.

4. the image compression
Almost all cameras are image compression and storage. Most are made as JPEG compression damage. Regardless of the compression level, how to, definitely lost colors and details. Now apart from professional cameras, more and more cameras start provides lossless compression TIFF format. This option is very popular with users ' favorite, but the picture file is relatively large, there are many 2048X1536 9Mb, most of the memory card are stored not a few. With the memory card capacity increases, the issue should be can't be effectively addressed. But we still hope that manufacturers can provide similar to RAW files smaller lossless compression format. But in the present circumstances, it would be better to focus on the camera in the best resolution generated the final file size. Image file size is smaller than the compression ratio 300K that is relatively high, this is likely to lose many of the details.

5. memory
Memory is essential for digital camerasIt is now indispensable device for digital cameras. Different manufacturers of memory differences are considerable. New models equipped with a removable storage card or built-in storage unit or both. Some cameras have a built-in storage units, only the storage card, it will be according to the manufacturer and camera model. Some older models only a fixed amount of memory and cannot be expanded, you'd better not to buy such old models. And different types of camera, built-in storage unit capacity is different, this indicator will affect the camera store file, continuous shooting speed. Therefore, other things equal it is best to choose a larger memory.
6. the digital and optical zoom
Because most civilian grade digital camera lens can be replaced, so many of the camera has a zoom feature. But you have to keep track of what is optical zoom and digital zoom. If you are the optical zoom is more practical. It should be noted that the lens is of maximum aperture will zoom to the telephoto end become very small, if so, in the telephoto end shooting your shutter speed would be impossible to get a higher shutter speed, it's possible photographs will be virtual. Note: digital zoom and not much use. So do not report on the digital zoom is too large, it is very banal, just put the photos for local amplification.

7. optical viewfinder
Be careful, some digital cameras there is no optical viewfinder, if you buy the camera, do be sure to have a spare battery. The LCD screen as a viewfinder, will soon run out of battery. Worse, most of the LCD screen in outdoor use under bright light. Purchase camera best equipped with a size suitable for the optical viewfinder. Many of the viewfinder size is too small, or no diopter adjustment, glasses of the user in the use of extremely uncomfortable when they feel, and many of the viewfinder is unable to correct the parallax. So be careful and be sure you're on camera viewfinder quite satisfactory. For paraxial viewfinder camera must have Parallax correction line and the diopter adjustment knob, if you can buy the TTL of the viewfinder so much the better.

8.LCD display
Digital cameras are usually equipped with a LCD display screen, it can be stored in the camera image preview and playback and delete. The best LCD monitor for active matrix (ActiveMatrix), because they show the brightest of the screen. The disadvantage is that it is better than any other type of LCD display power-intensive. Recent passive matrix (PassiveMatrix) display screen technology for some improvements, the screen clarity, even in outdoor is also clearly visible. But remember: LCD is famous for it's electric Tiger, you'd better save point.

Finally, do not see the LCD screen displays the photo effect is good to make a purchase decision. LCD screen often see on the actual scene of brighter, more saturated. By the way, check your camera's display screen location, because some camera display location not too good, in the optical viewfinder viewfinder nose dome in the LCD, you have to spend considerable time to wipe the grease stains nose forward.

9. control design
Complex control device is really annoying. Digital camera control unit should be easy to operate and understand, the user shall not be liable to the user manual to normal operation.

And control devices should be easy to reach, it is better not to frequently used features to the menu settings. If the photograph before you have to move the camera to the nose to find the control button, you will lose many opportunities.

10. Flash
A built-in Flash is very necessary. The camera should configure basic Flash control, in the light of local can auto Flash or Flash, turn off, for small portable camera must be equipped with a red eye removal function prevents shoot out of every one like rabbit eyes. If possible, try to buy a slow-sync Flash camera door, this function can take photos with a night person, let the characters and background have access to accurate exposure.

You should note the Flash range and regional or its index. Some types of Flash cannot fully cover shot of max shooting angle, angle of the photograph appears black. There are a number of Flash's range is too small to shooting distance distant objects. Finally, we need to pay attention to what the camera can add an external flash. General Flash shoe or external Flash sync terminal of the camera a little better.

11. image processing speed
After the photo shoot, digital camera, you must put the image stored in the memory. Image processing time from several seconds to several tens of seconds. During this period, the camera does not work, and is very sensitive to vibration, so time is as short as possible.

12. software
A digital camera is not enough, to get photos, you must leave it connected to your computer. Take a look at the camera onboard, and see if there is one called TWAIN driver attachment. This software can be downloaded from the image to the computer, or should have a plug-in (PLUG-IN). Most manufacturers will provide some image editing software, you can make adjustments to the image. Even on PHOTOSHOP like image software unfamiliar or you can use these simple software for image reset size, trim, adjust the contrast, color or sharpening. Carefully checked bundled software, some parallel imports is not this.

13. connection
Most cameras use the serial interface is connected to your computer, but this connection transfers data more slowly, no longer meet the increasingly large image files. Some manufacturers offer IrDA connection, use infrared to transfer the data. But your computer must be equipped with this function, there are many laptops and desktop PCs but very few. Some manufacturers provide IEEE1394 or USB connection mode, both the download speed is very fast. One IEEE1394 is mainly used in professional models, but the computer must have IEEE1394 interface; UComparison of universal SB, and general computer motherboards have a USB slot, is the ideal connection. If you do not have a USB connection, you can buy a USB card reader, you can only read a card, some are compatible with SM, CF card. You can most camera equipped with a cable. Some camera provides only the cable for PCs, Macintosh cable is intended for alternative. Make sure you select the camera to your computer is properly connected.

14. white balance control
This is a very useful feature. White balance enables you to control the camera filming scenes of judgment. Using this control, you can prevent a generation too dark, too bright, or because the colors are fluorescent light transfer of images. Mid-range and professional digital cameras often have this function. Although most cameras are equipped with automatic white balance control, but in a different light, auto white balance is still not fully meet the requirements. So the more senior digital camera provides multi-level white balance allows the user to select the light source.

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