Archive for December, 2008

The Magic Behind Digital Camera

Wednesday, December 10th, 2008
digital cameras
Harry Rockwell asked:

A digital camera, as opposed to a film or videotape camera, uses an electronic sensor to transform images (or video) into electronic data. Modern digital cameras are typically multifunctional and the same device can take photographs, video, and/or sound.

In 2005, digital cameras are starting to push traditional film cameras out of many markets. Shrinking device sizes have recently allowed miniaturized digital cameras to be included in multifunctional devices, such as cell phones and PDAs.

Classification

Digital cameras can be classified into several groups:

Video cameras

* Professional video cameras such as those used in television and movie production. These typically have multiple images sensors (one per color) to enhance resolution and color gamut. Professional video cameras usually do not have a built-in VCR or microphone.

* Camcorders used by amateurs. These are a combination of camera and VCR to create an all-in-one production unit. They generally include a microphone to record sound, and feature a small LCD to watch the video during filming and playback.

Still cameras

Digital still cameras are generally characterized by the use of flash memory and USB or Fire Wire for storage and transfer.

Most have a rear LCD for reviewing photographs. They are rated in mega pixels; that is, the product of their maximum resolution dimensions. The actual transfers to a host computer are commonly carried out using the USB mass storage device class (so that the camera appear as a drive) or using the Picture Transfer Protocol and its derivatives.

All use a CCD (for Charged Coupled Device) which is a chip comprised of a grid of phototransistors to sense the light intensities across the plane of focus of the camera lens.

There has recently been some application of a second kind of chip, called a CMOS (Complementary Metal-Oxide Semiconductor) sensor, and this chip is often differentiated from a CCD proper in that it uses less power and a different kind of light sensing material, however the differences are highly technical and many manufacturers still consider the CMOS chip a charged coupled device. For our purposes, a chip sensor is a CCD.

* Standard Digital Cameras: This encompasses most digital cameras. They are characterized by great ease in operation and easy focusing; this design allows for limited motion picture capability. They have an extended depth of field.

This allows objects at multiple depths to be in focus simultaneously, which accounts for much of their ease of focusing. It is also part of the reason professional photographers find their images flat or artificial-looking. They excel in landscape photography and casual use.

* Digital SLRs typically have a sensor nine times larger than that of a standard digital camera, and are targeted at professional photographers and enthusiasts. They resemble ordinary professional cameras in most ways, with replaceable flash and lens components, which give the user maximum control over light, focus and depth of field.

They are also bulkier and more expensive than their casual-use oriented counterparts. They are superb for portraiture and artistic photography because they can be customized for various applications with a comprehensive range of exchangeable lenses.

Professional modular digital camera systems

High-end digital camera backs used by professionals are usually separate devices from the camera bodies which they are used with. (This is because most of the large- and medium-format camera systems in professional use at the time that digital capture overtook film as the professional’s medium of choice were modular in nature, i.e. the camera body had multiple lenses, viewfinders, winders and backs available for use with it to fit different needs.)

Since the first backs were introduced there have been three main methods of “capturing” the image, each based on the hardware configuration of the particular back.

The first method is often called “Single Shot,” in reference to the number of times the camera’s sensor is exposed to the light passing through the camera lens.

Single Shot capture systems use either one CCD with a Bayer filter stamped onto it or three separate CCDs (one each for the primary additive colors Red, Green and Blue) which are exposed to the same image via a beam splitter.

The second method is referred to as “Multi-Shot” because the sensor is exposed to the image in a sequence of three or more openings of the lens aperture. There are several methods of application of the multi-shot technique.

The most common originally was to use a single CCD with three filters (once again red, green and blue) passed in front of the sensor in sequence to obtain the additive color information.

Another multiple shot method utilized a single CCD with a Bayer filter but actually moved the physical location of the sensor chip on the focus plane of the lens to “stitch” together a higher resolution image than the CCD would allow otherwise. A third version combined the two methods without stamping a Bayer filter onto the chip.

The third method is called “Scan” because the sensor moves across the focus plane much like the sensor of a desktop scanner.

These CCDs are usually referred to as “sticks” rather than “chips” because they utilize only a single row of pixels (more properly “photosites”) which are again “stamped” with the Bayer filter.

The choice of method for a given capture is of course determined largely by the subject matter. It is usually inappropriate to attempt to capture a subject which moves (like people or objects in motion) with anything but a single shot system.

However, the higher color fidelity and larger file sizes and resolutions available with multi-shot and scan-backs make them attractive for commercial photographers working with stationary subjects and large-format photographs.

Webcams

* Webcams are digital cameras attached to computers, used for video conferencing or other purposes. Webcams can capture full-motion video as well, and some models include microphones or zoom ability.

These devices range in price from very inexpensive to expensive higher-end models; many complex webcams have a servo-controlled base capable of tracking facial motion with the help of software.

Interpolation

Image color or resolution interpolation is used unless the camera uses a beam splitter single-shot approach, three-filter multi-shot approach, or Foveon X3 sensor.

The software specific to the camera interprets the information from the sensor to obtain a full color image. This is because in digital images, each pixel must have three values for luminous intensity, one each for the red, green, and blue channels. A normal sensor element cannot simultaneously record these three values.

The Bayer filter pattern is typically used. A Bayer filter pattern is a 2×2 pattern of light filters, with green ones at opposite corners and red and blue elsewhere.

The high proportion of green takes advantage of properties of the human visual system, which is determines brightness mostly from green and is far more sensitive to brightness than to hue or saturation.

Sometimes a 4-color filter pattern is used, often involving 2 different hues of green. This provides a wider color gamut, but requires a slightly more complicated interpolation process.

The luminous intensity color values not captured for each pixel can be interpolated (or guessed at) from the values of adjacent pixels which represent the color being calculated.

In some cases, extra resolution is interpolated into the image by shifting photosites off of a standard grid pattern so that photosites are adjacent to each other at 45 degree angles, and all three values are interpolated for “virtual” photosites which fall into the spaces at 90 degree angles from the actual photosites.

Connectivity

Many digital cameras can connect directly to a computer to transfer data. USB is the most widely used method, though some have a Fire wire port.

Integration

Some devices, like mobile phones integrates digital cameras. Mobile phone cameras are much more sold than standalone digital ones.

Storage

Digital cameras need memory to store data. The higher one goes in pixel size, the more memory will be needed. Cameras use a removable memory card to store data, but the cheapest and smallest cameras may simply use fixed internal memory instead. Some cameras come with inbuilt memory as well.

Autonomous devices

An autonomous device, such as a PictBridge printer, operates without need of a computer. The camera connects to the printer, which then downloads and prints its images. Some DVD recorders and television sets can read memory cards too.

Canon Digital Camera: Get the Best Cameras From the Leading Brand

Monday, December 8th, 2008
digital cameras
Jayson Pablo asked:

In the past, cameras were considered as luxury devices. There were old technology devices with which we had to wait till the whole camera film was consumed. After that we had to wait for a few days more till the film could be developed. But these days, there are hi-end cameras which allow us to capture and view pictures instantly. The user can even delete them if he does not like the picture. They have become an essential device to carry on a trip.

Everyone wants to memorize his or her past times. The constant improvement of technology has bought digital cameras into existence. With these superb devices, we can remember our good times when we had lived happily. They have become a passion for everyone. There are a multitude of companies in the markets which manufacture a huge range of video and hi-end cameras.

Canon is one of the popular manufacturer offering a superior range of digital still and video cameras. They offer high-quality features and tools delivering premium quality and performance. The user can view lively images captured by them. The mind blowing categories of Canon digital camera offer superior functionalities and performance. These categories include digital compact cameras and digital SLR cameras.

The first Canon digital camera came in 1996 which was titled PowerShot 600. Gradually, it introduced various digital camcorders. Canon continues to provide its consumers with superb technologies at cost-effective prices. Some of the top rated Canon digital cameras include Canon Powershot A590 IS, Canon Powershot SD 1100 IS, Canon PowerShot SD40 Digital ELPH, etc.

The Canon Powershot SD 1100 IS features 8 mega pixels camera with 3x zoom, image stabilization and auto focus for capturing perfect shot. The Canon Powershot SD950 IS offers features like 12 mega pixel, 3.7 optical & 4X digital zoom, 2.5″ LCD display, image stabilization, auto focus and a secure digital memory of 32 MB.

If the user likes to shoot quality images, he can find various brands at the online shops. Buying a Canon digital PowerShot S2 would be a great idea as it comes with the latest features. Some of the amazing features of this device include an optical image stabilization, a rotating LCD, USB 2.0 high speed support and Secure Digital memory cards instead of Compact Flash cards. All the advanced features of these hi-end cameras make them an essential part of our life. The user can find portable cameras in various brands. The popular compact powerful cameras are really easy to use and possess amazing features.

If the user is shopping for these cameras, he may be confused by seeing such a wide range of brands and features available in the market. Selecting the right camera can be an exhausting experience. When the user searches the online shops, he can find every manufacturer offering different types of cameras to choose from. Shopping online for cameras can be amazing if you get the right price with cost-effective deals.

Canon offers high quality products with cutting edge technologies and is amongst the most familiar and finest cameras in the market. This manufacturer is a leader in the compact digital camera class. They come with brilliant products at very competitive prices. The user can find a full range of high quality accessories too in their vast range of products.

Click outstanding digital photographs at the click of a button. Find a vast range of camera styles and features which satisfy all consumer requirements and makes their experience an amazing one. Canon designs and markets these powerful cameras with excellent range of features both for the novice and serious photographers. The fact cannot be denied that these cameras are manufactured with quality and superiority.

Before you select the camera to fulfill your photography needs, browse through the menu options and see if they are intuitive or not. Research on all the latest models and then select your favourite one.

History And Type Of Digital Cameras

Friday, December 5th, 2008
digital cameras
Roberto Sedycias asked:

A digital camera is such a camera that will take either video or still snaps digitally. It records the images digitally on a light-sensitive sensor. Some digital cameras can take still snaps as well as video and audio. The digital cameras have become very popular nowadays and more and more people are opting for rather than regular cameras.

Digital cameras are technologically much advanced and have many user-friendly features that are usually not found in regular cameras. One such very good feature is that it displays the image on the camera’s screen just after you catch it. Thus you can click and record millions and millions of pictures, keep the ones you want and discard the others. After the pictures or videos are recorded, you can edit the images and thus can be a virtual master of the background, people etc. Imagine the fun when you can change the background of a picture taken at your home to be changed to a Hawaiian beach, or changing the hair color of your sister to a wild pink and many other things. The choices are unlimited.

Nowadays digital cameras can be incorporated in many devices like PDAs or mobile phones or computers etc. Some astronomical devices like Hubble Space Telescope also use specialized digital cameras.

Digital camera technology has evolved from the similar technology that first recorded television images. It was in 1951 when the first video tape recorder was used to capture live images using television cameras. They converted the information in electrical impulses and saved the information on magnetic tape. It was actually due to NASA`s space technology that used digital images to capture photographs of surface of moon and advanced computer technology that led to major developments in digital photography.

Government was also using this technology in forms of spy camera and the time that being spy satellites and it contributed immensely in advancement of science of digital imaging. Soon private companies like Kodak, Sony etc were releasing professional digital cameras for ordinary people. Their strong marketing tactics worked and today digital cameras are found everywhere.

There are many varieties of digital camera and we will discuss some of them. Compact digital cameras are one of such varieties and are designed to be small as well as portable. The miniature versions are called subcompact cameras. Though they do not have much advanced features or excellent image quality but they are very simple to use and easy to carry around. Images are stored using Lossy compression in JPEG format. Such cameras are generally equipped with a low power, built-in flash usually sufficient for close subjects. Live preview is generally used for framing the photos. They are perfect for casual and home use.

Another type are Bridge cameras that are higher-end cameras. They resemble DSLRs and also share some advanced features with them but just like compact cameras, the photo framing is done with help of live preview and they also have small sized sensors. A Fuji film FinePix Bridge camera is also equipped with super zoom lenses that give you a chance to take very distant shots, though at the cost of image quality.

Another type is Digital single lens reflex cameras that are based on film SLRs or single-lens reflex cameras. These cameras are characterized by the presence of a mirror-reflex system. Other types include rangefinder and are generally used for film cameras, professional modular digital cameras that are assembled from different modular components and used for specific purposes. The common brands for such cameras include Mamiya and Hasselblad.

Make Your Digital Camera Batteries Last Longer

Wednesday, December 3rd, 2008
digital cameras
Roberto Sedycias asked:

Digital cameras, also known as filmless cameras are one of the most intelligent inventions of late. Because before digital cameras, even the most high end cameras were chemical process dependent for photo printout.

But in digital camera, images are recorded electronically by an inbuilt computer. Though initially they were beyond the reach of normal people due to price factor, now they are available in within an affordable range.

Battery is an important component of any digital camera. In fact the longevity of your digital camera depends upon the performance of its battery. First thing to remember is never go in for alkaline AA batteries as they have shorter life span. Always opt for rechargeable batteries called as NiMH. Although they are a bit costly as compared to alkaline AA digital camera batteries, but they can be reused for a long time.

If you are going out on a long trip, it is a good idea to take extra rechargeable batteries. You never know when they will come handy as digital cameras consume power from batteries quickly even if you use rechargeable ones.

While going on a trip, it is also advisable to take battery charger along with you as digital camera batteries may lose their charge over time. Having a charger is helpful especially if u r novice in digital camera photography for you tend to consume more batteries while clicking the perfect shot. Here are some other helpful tips to increase the longevity of your digital camera batteries.

It is always advisable to remove the batteries when the digital camera is not in use. This simple precaution can ensure the longevity of batteries.

Never let your digital camera batteries get wet as water can corrode the batteries and eventually damage them.

You should have prior knowledge about this fact that, if you are using MicroDrive media these miniature hard drives may take up quite more power than Compact Flash cards and hence extra rechargeable batteries are a must.

Turn off your digital camera when not in use. If you are in a situation where you must snap pictures quickly, this may not be a wise suggestion, but if you are in no hurry and can afford a couple of seconds before snapping a still subject, by all means, conserve your digital camera`s energy.

You do not need to stop and take a look after taking photo every time as by doing this does use up your digital camera`s battery power. However, once in a while, it is good to check if your exposure, lightening is perfect or not.

Now-a-days, many digital cameras come with regular viewfinder and an LCD viewfinder facility. While the digital LCD viewfinder has better resolution, it can drain battery power. Turn it off when applicable and use your regular viewfinder for taking pictures.

Try to keep your image playback to a minimum as they can drain out the battery power.

While replacing batteries in a digital camera, it is recommended that their mAh values match. The `mAh` stands for Milliamp Hour is a technical term used while describing how much power a particular battery will hold. It might be possible that one lesser mAh battery will drain before the others, resulting extra strain on the remaining batteries.

For better performance, do check in for an add-on power pack that uses AA NiMH batteries in your digital cameras.

When your AA NiMH batteries stopped accepting a charge, do not throw away them for they are recyclable. Contact your battery manufacturer or local recycling agency to see if these dead batteries can be recycled.

Always make sure to insert similar batteries into your digital camera battery charger. Miss-match set of batteries can result in damaging the batteries or the charger, and in extreme case, a fire too can ensue.

Taking proper care of your digital camera batteries ensures optimum and long lasting performance. Hope the above tips will come handy for the consumers of digital cameras.

Digital Cameras – How They Work

Monday, December 1st, 2008
digital cameras
Ted Burns asked:

Digital cameras come in various sizes, shapes, and specifications and offer a variety of impressive features.

Digital cameras are quickly gaining popularity around the globe. Many people already own one and routinely use it for their own pictures. Their use have become part of the culture among many communities and industries.

Digital cameras also have become part of a broad package of combined features with other hand-held tools, such as PDA devices and cellular phones. This makes the use of both devices much more convenient, having them combined in one, rather than two or more, functional instruments.

Digital cameras, moreover, not only can be used for still photos as with conventional cameras, but also for taking videos. An owner needs only to upgrade the camera’s memory card to increase storage capacity.

The marketplace offers a number of digital camera brands that provide a wide range of features. Olympus, Canon, Nikon, Kodak, and HP are some of the better-known brands of cameras offering the conventional 35mm to digital. Other key camera manufacturers include Sony, Panasonic, and Casio.

Digital Camera Considerations

Differing from conventional cameras, digital cameras have a small LCD screen, and sometimes an LCD screen plus viewfinder. The LCD screen is similar to TV screens that allow the photographer to see the picture, even before snapping it. Some have large screens that enable the photographer to see more of the subject and background.

Digital cameras also come with memory slots that hold a memory card or “stick.” The amount of memory available in them ranges from megabytes to gigabytes. Of course, the more memory, the greater the cost. However the extra storage capacity may be well worth the additional expense.

Another purchasing concern is the battery. Some digital cameras use disposable batteries. However, they wear out quickly, so most people recommend rechargeable batteries for longer energy life. Typically a rechargeable battery and a charger come in bundle with the camera unit.

Finally, consider the way the pictures are downloaded. Though many digital cameras come with a USB port which easily connects to a computer, there are others that necessitate removing the memory card and positioning it with a reader to download pictures.

Digital Camera Features

Camera buyers should know at least the basic features of their camera of choice before making an expensive purchase. Though the snapping of pictures is fundamentally the same from camera-to-camera, there are features that make one brand more appealing than others.

For example, the number of mega pixels used when taking pictures – meaning millions of pixels that help with the clarity of the pictures – should be one of the primary considerations to most buyers. Pixels are the individual “dots” that make up the content of pictures.

As such, cameras offering a greater number of pixels can produce larger images with better resolutions than those with less. Be aware, though, that cameras using a more pixels consume more camera memory when storing the images.

The camera’s zoom function is also critical. Most digital cameras are enhanced with a two-zoom capability; the optical and digital. Optical zoom uses a moving lens and makes the subject in the picture appear closer, while digital zoom crops or stretches the image.

Finally, don’t neglect the importance of the camera case’s durability. Some digital cameras are made predominantly of plastic materials – and are consequently more fragile – while others are comprised of a combination of plastic and metal alloy.

Either type has limitations in the amount of jarring that can be sustained without internal damage. Spend a little extra money to purchase a case that will protect your camera investment.