Digital camera common questions FAQ

Q: I shoot digital photos often appear out of bright or dim side of the case, may I ask why there will be a digital camera metering errors happen? How to make?

A: The digital camera automatically metering is based on "standard dust" to determine, is the assumed rate is reflective metering region 18%, followed by determining the ratio of the metering aperture and shutter values, source of 18% of this value according to the natural landscape in the middle of the performance may be reflective tone, tone if the majority of white viewfinder screen, then if the camera automatically determine the aperture metering Shutter value to shoot, then get the photos taken will be an underexposed photo white background will appear gray hair looks so reflective rate of more than 18% shooting scene, the need to increase the HP pavilion dv7 battery replacement camera's exposure compensation value, whereas if the reflection rate of less than 18% shooting scene, for example, black background, shoot Photos tend to have exposure, black background will become gray, so the reflection rate of less than 18% of the shooting scene, the need to reduce exposure. Simply means "white with black cut."

Although digital images can be post-digital darkroom processing to adjust the exposure, but for an overexposed image, shadow detail and levels have all been lost, in order to adjust the back is difficult, but if it is less exposed serious photo, correction occurs after exposure more noise, the details will be lost, so try to get pictures taken with the correct exposure.

Q: The computer can only display JPEG files 24BIT full color, that is, a digital camera as long as the configuration 8BIT the A / D converter will be able to meet the need, but why use more than one converter 10BIT it?

A: The reasons are as follows: First, the high-end digital cameras usually use RAW format photographs, RAW when shooting can fully record all the raw data, get rid of the shackles of JPEG standard, to achieve the perfect color and quality performance. Second is to increase the combined calculation of the reference digital image data, some of the DSP digital camera with enhanced resolution for the program forces, this program mainly with reference to neighboring pixels of pixel sampling performance, do a statistical made. Thus, BIT the higher the A / D converter to sample with more parameters, relative to the combined 24BIT JPEG file out of the performance better.

Therefore, each digital camera red, green and blue more than the output to be at least 10BIT (1024 gray scale) for the job is currently configured 12Bit most of the A / D processor. Individual high-end products is reached 14BIT.

Q: I would like to ask sensitive CCD ISO ability to improve the methods are there? Another CCD's exposure latitude is much worse than the traditional film it?

A: Use a fixed CCD camera as a light-sensitive components can not be like a traditional film camera, to be replaced as selected higher or lower photographic capabilities. To increase the capacity of CCD ISO there are usually two ways, first, simplify the CCD from a particular region to improve the signal pixels on the ISO, because it can not be physically larger CCD sensitive area, through joint matrix to simulate the handling of large photosensitive area way, so the higher the ISO to be relatively lower resolution. Another way is through a specific signal enhancement circuit, according to data operations to obtain a reasonable performance of the exposure, but usually accompanied by noise generation. Therefore, the maximum ISO value of the HP Pavilion dv4 battery pack digital camera is mainly dependent on the maximum acceptable signal to noise ratio (S / N).

Under the accurate exposure, CCD better than traditional film to capture images of a wide tonal range. An ordinary CCD can record 250:1 (eight aperture) around the high-contrast scenes. High-end FF CCD system can handle nearly 1000:1 tonal range. However, the final output image on photo paper only reappear about 32:1, or 5 aperture range of hues.

Q: I'm going to buy a digital camera, mainly for landscape shooting, what is the market big 10X zoom product better? How to determine the reasonableness of the digital camera focus?

A: The telephoto digital camera does have many unique advantages, such as can be taken to far away objects, and can capture a close-up photo of the background to the virtual. But for shooting scenery, the wide-angle is the most commonly used. To record bits and pieces of daily life, wide-angle can be better qualified for the job. The telephoto cameras on the market today, and its wide-angle 38mm focal length is usually around, for the average home user and the users love landscape photography, this focal length and not too reasonable.

So from your demand, I suggest you choose a digital camera with wide-angle lens. The camera should be at least 28mm wide-angle end of the following, now meet the requirements of the products on the market a lot, even to the end product of the wide-angle 24mm, very suitable for landscape photography.

Q: Will the number of ordinary digital camera Why is the focus more than it? Can even be free to choose the focus, and more What are the benefits of focus?

A: For SLR cameras, the more focus and focus on the selection means high prices. This is determined by the structure of SLR cameras, the focus is a separate component, in order to ensure high-speed AF, selectable Focus range and location are very limited. The common digital camera's focus is to test the designated area on the CCD imaging, phase analysis done by AF, so in theory any of CCD position, of any size are able to separate out the regional analysis and focus, then 5 The above points focus on a few products, some products are even free to choose to focus. Such as the Canon 2002 years later, almost full range of products also have the ability AiAF, center of the screen that can move freely on most of the focus areas.

Flexibility to pursue creative, photography veteran often dull and will not be subject to the composition placed in the center of the screen, to free choice of focus, innovative composition will bring great convenience, no matter what position the main body, can the focus will shift in the past, dedicated to the composition without the need to focus distraction.

Q: I am a digital photography enthusiasts, often for a long time to go out shooting, going to buy a "digital companion" to store photos, may I ask how to choose?

A: At present the market "Dell Inspiron 9400 ac adapter digital camera companion," many types of products, most of the photos used only for storage, but some products have started to offer color LCD display and more features, and some products are not simply the sense of digital camera partner, and also can be used to listen to music, watching movies, playing games.

Simple "digital camera companion," is bound to be a transitional product, I suggest you purchase multi-functional products, but such prices are usually more expensive, so you can consider buying second-hand pocket notebook. In fact the price of memory cards is now much reduced, two 1GB CF card or SD card prices, but some one thousand, you can store thousands of photos, fully able to meet the needs of ordinary film, "digital camera partner" role is not very big.