Digital cameras are quite similar to traditional cameras in their operation. They both have a lens to focus the image, a shutter to allow light inside the camera, and an aperture to control the amount of light which enters the camera.

The differences between digital and traditional photography occur 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 measure light intensity. The most common 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 amplified 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 processed the resulting image is stored on a memory card.

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

The coloured 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 coloured image. This is done by analyzing each individual 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 actually 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 data cannot be recovered, so JPEG is called a ‘lossy’ format.

Many 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.

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Throughout the ages humanity has always been fascinated by the possibility of “capturing moments” or in other words perpetuating moments of high significance and outstanding beauty. This provided the opportunity to share something that nobody else has seen or perceived. This idea has made a long way from canvas-paintings to using cameras. Cameras, in their turn have also experienced a rather fast evolution and nowadays everybody has a notion of what a digital camera is and the majority of people use digital cameras.

What is a digital camera? According to a standard definition a digital camera is “?opposed to a film or video camera, uses an electronic sensor to transform images and video into electronic data”[1]. Years ago people used to possess two different devices in order to take pictures and to make video. The need to spare space and make it more comfortable for people to do both things with higher quality results catalyzed the creation of digital cameras. The multifunctionalism of digital cameras and the combination of several devices in one make it the best possible choice for a modern man.

For years a digital camera has been unaffordable for many families, nevertheless, nowadays the great variety of digital cameras of different manufacturers and diverse prices make a digital camera a potential purchase of almost every single family. The formula: price + quality = satisfied customer used by the digital cameras manufacturers is especially reflected in the wide choice of cameras that offer the best quality standards for the price-range they belong to.
How to choose a digital camera?

The transition of digital photography from the privilege of rich people to an ordinary home appliance has caused some problems. That is the reason a modern man has a set of questions concerning digital cameras, especially the what’s, why’s and where’s of digital cameras. Nobody wants to make a “miscalculation”! The basic problem in choosing a digital camera is a “guarantee” that the device you are purchasing will “grow old” in couple of month due to a constant improvement and development of the sphere. The only factor that may delay this process of “growing old” is purchasing a device with the price twice or three times higher of the average market price for a digital camera at the moment.

If a person chooses a digital camera there are several criterions of a great priority he needs to keep in mind: price of the device, the image resolution of the camera, the capacity of the memory card, presence of a LCD-display, the interface of the camera, its weight and size. The price of a digital camera depends on its quality factors. The resolution of a digital camera, or in other words the “size of a digital image” is measured in pixels. Pixels in their turn are photosensitive elements. It is common knowledge, that the bigger is the amount of pixels indicated in the camera properties the better it is. Therefore, if a high-detailed photo is required, the usage of zoom on a digital camera with small resolution will not give the desired result. In this case a person choosing a digital camera needs to exactly know what it will be used for and to choose it according to its future destination. It is necessary to mention that the resolution of 640″x”480 is the lowest resolution any customer should be orientated to. It is the minimal resolution with witch the purchase of a digital camera still remains reasonable.

The lens of the camera or “the zoom properties” mentioned above allows saving a lot on the price of the device but hits the quality of the pictures obtained. The memory card is a very important issue, too. It is much better to choose a better camera with a lesser memory capacity than an overage digital camera with a larger memory capacity. The presence of the LCD-display is no longer a “wish” it is a requirement for any digital camera. It allows to choose the future image, to anticipate it and to delete bad images and therefore to save space.

The advantages of digital cameras

Along with some advantages mentioned above there are more to digital cameras than that. It goes without saying that it is possible to examine and sort out the images, create a slide show, a digital photo album, create a presentation on your computer, a ordinary TV or a multimedia projector. A digital camera offers the ability of sending images for printing directly to the printer with a DPOF standard or throughout the USB without using the computer. The images from the digital cameras may be sent throughout the Internet. For instance, it is possible to send images to colleagues, friends or relatives using e-mail. In the era of the constant lack of time this advantages become issues of the highest priority.

Affordability and manufacturers

There is a plenty of digital cameras for sale in the price-range from $300 to $9000 and more. What camera would become the best choice? An ordinary digital camera with the price around $300 is suitable for everyday usage. So do not expect any super possibilities from a camera like that. The variety of manufacturers is very wide. Nevertheless it is necessary to mention the most popular brands among the customers. They are: Sony, Canon and Nikon. And some others: Casio, Fuji, HP, Kodak, Konica, Olympus and Pentax. The most popular digital camera nowadays is Sony Cyber Shot DSC-P150.

Conclusion

Digital cameras find more and more place in the lives of contemporary people. Due to the comfort and quality of making images they are rightfully displacing ordinary old cameras from the market. After all, this is very simple: take the picture you want, connect the digital camera to your computer and open “the boundless elbowroom” of its opportunities. You may immediately print the images or by means of special programs make the images brighter, add shrill and so on. The quality of the images is much better than on the film cameras. Smart Media Card or Сompact Flash memory cards store the images and do not let them to get old. Digital cameras are the right choice of the new millennium!

John Nilson is a senior writer at Custom Essays Writing Service. He is an experienced writer of custom essays and term papers and will be glad to share his experience with you.

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There is so much that you can do with compact digital cameras that you just couldn’t do with film cameras, and the switchover from film to all digital photography is well underway. When you think of how easy it is these days to just snap a photo, save it on a reusable media card, transfer the file to your computer later that day, alter the photo as you like in your favorite photo editor, and then either print it out on photo paper or send it to your friends around the world, it’s no wonder that digital cameras are all the rage. But before you buy a compact digital camera, here are some things to look for:

Probably the most important consideration these days regarding compact digital cameras is how many megapixels they have. Actually this is how most digital cameras are grouped these days, so you need to understand what this designation means. Basically, a megapixel is capable of storing a million bits of information about a photo. So the more megapixels you have the more information you are storing about every photo you shoot. So before buying any compact digital camera you need to decide how you intend to use it.

Will it mainly be used for just 4×6 snapshots? Will you be enlarging some up to 8×10 or even higher? Do you like to crop out a portion of the images in your photo editor and enlarge them? The answer to these questions will help determine what megapixel camera will suit you best. This is because most 3 megapixel cameras can produce enough information about a photo to print a sharp picture on up to 8×10 or so. So if all you do is take snapshots you really don’t need to pay for any more megapixels. However, if you like to make enlargements beyond 8×10 or you like to enlarge just a portion of each photo, you will need more megapixels, perhaps 5 or 6. And for those who are dedicated hobbyists who may want to produce super enlargements, you might want to consider even larger megapixel cameras.

Another important consideration especially for compact digital cameras is their size. Just as the name suggests, they are very compact. There is even an ultra-compact digital camera category too. Initially it all sounds good to make cameras smaller and more lightweight, but sometimes it seems that the camera manufacturers have gone a bit too far with some models and the dials and controls are so tiny that they are hard to manipulate for some folks whose hands may be larger. So before you buy any compact digital camera be sure that you actually hold one in your hand and work with it for a while so you know that it will fit you personally.

Once you have hand tested the models that interest you most, you can then look for them online and often will save a lot of money that way. There are several good online electronics retailers that offer significant compact camera discounts. So shop around and look for those online retailers that have a good reputation and have been in business for a while to get your best compact digital camera deal.

Thad Pickering writes on many consumer related topics including audio and video. You can find out more about digital camera best buys and cannon digital cameras by visiting our Home Theater website.

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