Looking at the most intricate details of the digital camera as a technologically advanced device a lot of functions come into play. Such s a point is that of the digital camera metering. This discussion focuses towards that intention of understanding and knowing the details of the component. Basically speaking the metering system in a digital camera measures the amount of light in the scene and calculates the best-fit exposure value based on the metering mode explained below. Automatic exposure is a standard feature in all the digital cameras. All that is requires to be done is select the metering mode, point the camera and press the shutter release. Most of the time, this will result in a correct exposure. The detailed explanation and analysis of the entire process is as follows in the next lines of this discussion.

The metering method defines which information of the scene is used to calculate the exposure value and how it is determined. Metering modes depend on the camera and the brand, but are mostly variations of the following three types. Primarily, matrix or evaluative metering. This is probably the most complex metering mode, offering the best exposure in most circumstances. Essentially, the scene is split up into a matrix of metering zones, which are evaluated individually. The overall exposure is based on an algorithm specific to that camera, the details of which are closely guarded by the manufacturer. Often they are based on comparing the measurements to the exposure of typical scenes.

Next comes the center-weighted average metering. This is probably the most common metering method implemented in nearly every digital camera and the default for those digital cameras that don’t offer metering mode selection. This method averages the exposure of the entire frame but gives extra weight to the center and is ideal for portraits. Another important is the spot or partial metering. The spot metering allows the user to meter the subject in the center of the frame or on some cameras at the selected AF point. Only a small area of the whole frame is metered and the exposure of the rest of the frame is ignored. This type of metering is useful for brightly backlit, macro, and moon shots.

Again a lot has been revealed and a lot remains to be done so, yet the rudimentary foundation of string fundamentals can be established via the lines of the above lines of this discussion. It is only hoped that the lines get their true respect from the readers of them and users of the digital camera to properly deliver the due respect that the digital camera metering technique deserves.

About The Author

Jakob Jelling is the founder of http://www.snapjunky.com. Visit his digital camera guide and learn how to take better pictures with your digicam.

Buying a digital camera is great fun, particularly if you’ve never had one before, because you can take loads of great photos without the expense of having to print them all of before you can see which ones worked well. But if you want to get the best out of your digital camera and extend its life, then you need to spend a little extra on some digital camera accessories, some of which might include:

One of the most sensible digital camera accessories you can buy is a soft camera case. These are usually only $10 to $20, but can be worth their weight in gold if you drop your camera or are careless with it. A soft camera case won’t protect your digital camera from everything, but it can protect your camera from damage in many instances. If you expect to be traveling a lot, it might be better to buy yourself a strong camera bag for extra protection.

A lens cleaning kit is another very important accessory. Buy a good quality kit, preferably from a reputable camera dealer. Never clean the lens or any other optical part of your camera with a shirt, water, breath or fingers. A good kit should only cost a few dollars, and include a soft cloth, a small blower brush, some lens cleaning solution and some lens cleaning tissues.

Rechargeable batteries. Including a spare set, are a definite necessity. It’s amazing how often the batteries in your camera will go flat at the worst possible moment. So having a spare set already charged is a great idea. If you take a lot of photos you’ll find you go through a lot of batteries, so although rechargeable batteries are more expensive up front, they’ll pay for themselves very quickly. It also means you don’t have to try and find a shop selling batteries when you’re in the middle of nowhere. You’ll also need a battery charger or an AC adapter. Personally I think the charger is more useful, because you can be charging up one set of batteries while still taking photos with another. With an AC Adapter you’ll have to wait for the battery to recharge.

Most digital cameras come with a memory card that is either 16 or 32 MB. Most people find this isn’t enough, so it’s probably a good idea to buy yourself a larger memory card. That way you can take more pictures at a time, and will have to make less trips to the computer to transfer the ones you’ve taken. You can also use a number of smaller memory cards if that works better for you.

A tripod isn’t an essential digital camera accessory, but it can certainly be a handy one. A tripod is particularly useful if you’re taking photos at a shutter sped below 1/60 second, so that you can reduce the effect of camera shake. Some cameras have an LCD monitor that has a blinking light that flashes when the shutter speed is low enough to cause camera shake. You also need a tripod if you plan to do lots of macro photography and are too close.

Digital cameras have their own flash unit, but these have a limited range. However if you’ve bought a high-end digital camera, then it may include a horseshoe so that you can include an external flash. This can be useful if you like to experiment with different lighting effects, or simply if you find the camera’s own limited range too frustrating.

Don’t spend another dollar on a digital camera accessories without first visiting Digital-Photo-Tips.info where you will find valuable information on the advantages of digital photography, tips on how a digital camera works and a digital camera buying guide that could save you money on your next digital camera.

Digital cameras are basically the same as film cameras in their handling. They both have a lens to focus the specific image, a shutter to let light inside the camera, and an aperture to control the amount of light which enters the camera.

The differences between digital and traditional photography happen to be after the light enters the camera. A traditional camera captures the images on film, while a digital camera captures the image on an image sensor.

Image sensors are electronic devices made up of an array of electrodes (or photosites) which calculate light intensity. The most universally recognized type of image sensor for digital cameras is the CCD (Charge-Coupled Device) although others such as CMOS and Foveon are sometimes used.

The number of photosites in the image sensor gives the digital camera its megapixel (millions of pixels) rating. Each photosite corresponds to a pixel in the final image, so a camera which is rated at six megapixels, for example, has an image sensor which is 3008 pixels wide by 2000 pixels high.

When light hits the image sensor it is converted into electrical signals which are built-up and fed to an analog-to-digital (A/D) converter. The A/D converter changes the electrical signal into binary numbers which are processed by a computer housed in the camera body. Once the numbers have been harvested the resulting image is stored on a memory card.

Photosites can only measure intensity of light — not color. In order to produce a colour image, each photosite must be covered with a colored filter which can be red, blue, or green. These are the three primary colors which can be combined to produce any other colour including white.

The colored filters are arranged in a grid so that there are twice as many green filters as there are red or blue. This is because the human eye is twice as sensitive to green light. Filters are arranged in a pattern called the Bayer pattern - one row of red, green, red, green (etc.), and the next row of blue, green, blue, green (etc).

Since each photosite can only be covered with one coloured filter, computer processing is necessary to produce a full colored image. This is done by analyzing a certain pixel and its immediate neighbors and producing a composite colour from these calculations. For example, if a bright red pixel is surrounded by bright green and bright blue pixels, the bright red pixel must undeniably be white, because white is the combination of red, blue, and green. This process is called demosaicing.

After demosaicing the image is adjusted according to the settings on your camera. Most cameras have settings for brightness, contrast, and colour saturation. After these adjustments are made some cameras may also apply a sharpening algorithm to make the image clearer.

The final step before saving the image on the memory card is to compress it. Most cameras use JPEG as a compression format. This reduces the size of the file by eliminating excess data. This information cannot be recovered, so JPEG is called a ‘lossy’ format.

Several cameras have the ability to save uncompressed images as TIFF files or raw data. Raw data is the original photosite data even before demosaicing. It can be transferred to a computer for processing with special software that will perform all of the processing functions of the camera but with much greater control.

Drew Laughlin is a photographer extraordinaire. Digital Photography is a true passion of Drew’s and he loves sharing his research, reviews and information to help people become better photographers and help them choose the best digital camera for their needs. You can learn more about Drew and recieve a ton of free, vlauable Digital Photography information at http://www.learn-digital-cameras.com.