Urgent! ! ! How to identify whether a digital camera is used for the first time? How to check the camera quality by yourself?

You can call the Consumer Protection Association for information.

Interviewee: phwjmj level: Novice (2005-12-0713: 42:14) It is very simple to identify whether the camera is used for the first time. You only need to take a photo with this camera, and then input it into the computer, and you can see the file name of this photo in the computer. Such as Dsc00002, DSCN2005, etc. Don't look at the English letters in front (because different cameras have different letters), just look at the numbers at the back. If the camera is taking pictures for the first time, its number must be 0000 1 or 000 1. Of course, if someone else has tried it like you, the number may be 00002, which should be regarded as the first time to use it. After you buy a digital camera, you can know how many photos you have taken with it in this way. The most reliable way to detect the quality of a camera is to look at the quality of the photos it takes under different conditions.

1: According to the 800 820 6027 telephone provided by the manufacturer, the serial numbers of the fuselage (each unique) can be used to identify the authenticity.

2: The warranty card and camera serial number have been.

3. China Insurance Company's national warranty card, with three guarantees of after-sales service.

4. Simplified Chinese instruction.

(Don't open the seal)

On the identification of two mobile phones;

1, look at the label. See if there can be no burr on the edge of the label, or if the film paper on the label surface will tilt at the edge, and whether the label and the edge will be stolen (black, only for non-black cameras);

2. Look at the interface. Usually the pictures are transmitted by USB, and there must be traces of friction at the interface;

3. Look at the gap (small space). See if there is dust in the gap (small space), that is, check the sanitary dead corner, and the new machine will not have dust.

4. Look at the photo number, which is usually 4 digits, and the last digit should be 1.

This is my experience in using a unit camera.

Regarding the quality test of cameras, the most important thing is to test the bad points and noise of CCD (image sensor). The following are specific methods:

1. Turn on the camera, warm up 1-2 min, use this time to enter the menu, turn off the date printing function (the new machine is turned off by default, so it is not new when it is turned on), turn off the noise reduction function (by default), and turn off the image effects (sharpness, contrast, clarity, saturation, etc.). Are turned on normally), turn off the film reversal effect, and automatically white balance. Then cover the lens cover, and the machine without the lens cover firmly covers the camera lens with a flat, dark and thick notebook. If possible, wrap the lens in a black cloth. Image format is the most commonly used jepg fine. Some automatic machines automatically open the shutter to reduce noise when they are slow, and the solution is discussed in the second article.

2. Start the test now. Don't zoom. First, test the bright noise/bad points at the lowest iso. Needless to say, full manual and partial manual, you can manually adjust the iso to the minimum. If there is no manual camera, the following methods will be used. Use the fastest shutter and ordinary shutter (1/250s,1125s, 1/30s,115s to 1s). Automatic machines can't determine the shutter, so they take pictures in night mode instead of the slowest shutter sample (iso is generally the lowest at this time, but some machines will automatically turn on noise reduction); Use night portrait mode (blocking flash) instead of 1s shutter to take proofs; Turn on the flash with automatic gear (P gear) (automatic flash mode, remember to block the flash) and take a sample instead of1/60s; Replace the1125s sample with the landscape mode; Replace the fastest shutter sample (if any) with the motion mode (if not, forget it). Except for night scene mode, the above alternatives will not be turned on. Don't worry.

All the above tests are bright noise/bad points, which reflects that the leakage, short circuit and breakdown of ccd complementary oxide elements will lead to bright noise/bad points. The so-called bright noise/bad point is the point on ccd that is always abnormally overexposed. It is also necessary to test the following dark noise/bad points, which reflect the burning, open circuit, even oil leakage and ash entry of ccd elements. On the contrary, dark noise/bad spots are always insensitive to light on ccd.

3. Open the lens cover or remove the object blocking the lens and start testing the dark noise/bad spots of ccd. Many people don't take this test. I have helped many people test the country and found that many friends have encountered this situation, which sometimes affects the quality of photos, but I regret it after the replacement period, so I have to say it here. Remember: If your machine is not new, the dark noise may be caused by ccd dust/oil leakage. Aim your machine at a piece of pure white paper. White paper has better lighting. Use a small desk lamp to increase lighting. Fluorescent lamps use automatic white balance, incandescent lamps use incandescent lamps (halogen lamps) white balance, and other settings remain unchanged. Fill the picture frame (viewfinder) with white paper and keep a distance of about 20cm to prevent the machine and hands from blocking the light because they are not too close.

For fully manual machines, use manual gear shifting, and the shutter is gradually accelerated from 1s to shoot all-white test films. Remember that the key is that the white paper is overexposed by more than 2 steps (the machine will mistake the white paper for 18% gray scale instead of 0% gray scale! Refer to the manual exposure meter to adjust the aperture and overexpose for more than 2 files (preferably 3 files) to shoot all-white films. Gradually increase the shutter speed until the aperture can not meet the overexposure of more than 2 gears. This process can be realized by shutter priority and exposure compensation. This series of tests estimated that the shutter speed could reach about 1/60s. Of course, someone must want to know how to test the dark noise/bad point at a faster shutter speed, but this is not necessary. Brothers who must try, first, can increase the lighting of white paper, and second, can cooperate with flash (overhead/external connection). Turn on the flash by force. If the output power can be adjusted to the best (for example, fz20), the output power of the flash can be increased by more than 2 steps, and the shutter is used to shoot all-white films first. For the machine that can't control the power of the flash, turn on the flash forcibly and raise the aperture by 2-3 steps. If the default aperture of your machine is already the maximum when using the flash, it will be miserable. Because the shutter in flash photography has lost control of the subject exposure. Under the condition that the flash can be synchronized, the shutter speed that can be achieved by various machines is different, but it can generally reach 1/250s (consumer dc is generally a vertical focal plane shutter). Faster shutter can only use advanced flash, so don't test it again! Anyway, we got a series of all-white test films.

Without a manual machine, you can also shoot various test films (landscapes, portraits, banquets, beaches, etc.). ) by using exposure compensation. Remember to increase the exposure by more than 2 steps. There is no need to increase exposure when shooting in night scene mode, which can replace the test of the slowest shutter.

4. Finally, the software detects these all-black/all-white proofs. First, use acdsee, photoshop and other software to open all the white proofs, turn them into all-black films and save them back (don't mix them together). Then use Deadpixel test software to test all-white/anti-all-white proofs. First, set 60/250 with the default parameters. Anything over 60 is bright/dark noise. Remember their coordinates. /kloc-fixed noise above 0/can be replaced at that time, and fixed noise above 3/must be replaced within 7 days after purchase. If it exceeds 250, it must be changed. For the noise in the anti-black film, if there are many noises connected together, the old machine is probably ccd dust/oil leakage. If you want to compare the noise control ability of various cameras (without more than 60 noise points), it is suggested that each sample be tested with 5/20 parameters. The less noise, the same noise control ability of this camera in theory (the same shooting parameters).

5. By the way, how to test the bright spot of LCD. Use your LCD to browse any tested noiseless black film. If you can see bright spots on the LCD screen, you can ask for replacement, although it will not affect the photo quality.

6. Emphasize that the dc lens without lens cover must be tightly covered when shooting black films, and the cover must be thick, flat and opaque; Be sure to overexpose the white film for more than 2 files and clean the white paper; I believe I have made other details quite clear, so you might as well pay more attention.