Buying the best digital camera for your needs

Choosing the best digital camera can be a daunting task with the wide number of choices available in today’s market place. There are lots and lots of things that you need to keep in mind while going to choose a camera for yourself. The best digital camera for your friend might not be the best option for you.

So, the first question that you need to answer is that for what purpose you are planning to buy a digital camera. Is it to take photos of your family while on vacation or are you planning to become a photographer? This will help you to narrow down your choices to a limited few. So lets take a look at the options that we have :

A camera for emailing photos, taking family photos etc. : Most people use a digital camera for taking personal photos and then emailing them to family and friends. For this purpose, a simple and relatively cheap camera costing $100 to $200 and having a 2 mega pixel range is sufficient.

A camera for photographing images for online auctions : With more and more business taking place through the Internet, you might also need a camera to take photos of your antique furniture which you would like to sell. So, you need a camera which can take pictures at an extremely close range, say within 12 inches of the object. Thus, a camera consisting of 3-4 mega pixel is suitable for such purposes. The prices of these cameras are falling nowadays since they fall into mid-segment, i.e. they are neither hi-fi nor low end. So if you go and do a little bit of research, it is most likely that you will hit a good bargain.

http://www.great-digital-cameras.com/best-digital-camera.html

The Inside Picture Of A Digital Camera

Electronics greatest technological breakthrough in this modern age is the digitization of analog signals. Digital information, which is represented by 1s and 0s, is formed upon successful conversion of analog information, which is represented by a fluctuating wave. This conversion of analog to digital has made the world of science and technology make great advances into the field of computers, Internet, satellites, and space research.

On the consumer domain, the benefits of this technological breakthrough can be witnessed in consumer electronic products like TVs, computers, cameras, camcorders, CDs, DVDs, etc. Digitization gave rise to microchips, which could be programmed to perform any task. With the utilization of the microchip, the digital camera was born.

In a digital camera, the lens focuses the image, the shutter allows the entry of light reflecting from that image into the camera, for a fraction of a second, and the aperture determines the quantity of light allowed inside the camera. When the light enters the camera, it does not fall on a photographic film as it does in a conventional camera, rather it falls on an image sensor.

The image sensor is an electronic device, a semiconductor, made up of photosites that measures the light intensity. The photosite can only measure the intensity of light and cannot recognize any color. To overcome this, each photosite is covered with a color filter of red, or a green, or a blue color according to a pattern known as the Bayer pattern. Since the human eye is twice sensitive to the green color, the number of photosites having green color is twice the number of photosites having red or blue color. Millions of photosites are covered by this Bayer pattern. Each color occupies a single photosite, which is known as a pixel.

The more the number of pixels, the greater is the amount of detail that can be captured. The detail of the image is called as resolution, which is determined by the quality of the lens and the number of pixels in the image sensor. High-end digital cameras have about 12 million pixels, whereas professional digital cameras have about 20 million pixels.

The information of the pixels is recorded as electrical analog signals, is amplified, and then is fed into a converter, which converts the amplified analog signals into digital binary numbers, with respect to the color information of each pixel. These digital binary numbers are then fed into a computer chip residing inside the camera. The computer chip analyzes the digital binary numbers that have been made as per the color of individual pixels. This information is known as RAW data. For analysis, the computer chip subjects this RAW data using a technique known as demosaicing.

In this technique (demosaicing), the pixel color is determined as per the color of the neighboring pixels. For example, if a red color pixel is surrounded by blue and green pixels, then that red color pixel is treated as white color, since the color white is a combination of the colors, red, blue, and green. After demosaicing is complete, the image is further subjected to the photographer`s settings of the camera, like adjustments made for brightness, color saturation, contrast, etc.

High-end digital cameras usually do not do anything more to the image thus produced. However, professional digital cameras have a sharpening algorithm, which heighten the sharpness and clarity of the demosaiced and settings adjusted image. Professional digital cameras also have the option of saving the image in its RAW data before any demosaicing or adjustments are made by the computer chip. This is to give control to the professional photographers to make changes to the RAW data as per their own choices.

The image can be saved in an uncompressed format like TIFF or a compressed format like JPEG. Uncompressed formats preserve greater information; thus, the detail of the photograph is much more than a compressed format, where detail is less, as lesser information is stored. Hence, compressed formats are also known as lossy formats, since details are lost. An uncompressed format increases the file size, whereas a compressed format reduces the file size. Depending upon the need, the image can be saved either in an uncompressed or a compressed image format, as bits and bytes in a memory card. The stored image can be viewed on the digital camera`s display screen as a digital photo.

This digital photo can then be transferred from the digital camera to the computer`s hard disk via the serial port or USB port or FireWire port or Bluetooth wireless using Wi-Fi connectivity. RAW data and uncompressed data like TIFF take a longer time to transfer than compressed data like JPEG or GIF.

Once the data has been transferred to the computer`s hard disk, any photo editing software can manipulate and adjust it, as per the individual tastes and requirements of the photographer. The digital photo can then be printed on photographic paper, specially coated paper, or any other paper via a color inkjet or laser printer. Utilizing a plotter, it can be printed in larger sizes, in any other medium like canvas, acrylic, vinyl, etc. The digital photo can be saved on a hard disk, pen drive or a CD, for archival purposes.

With passing time, more and more features are being introduced in a digital camera. Nowadays, audio-video recording is also fused with the still image capturing capability of the digital camera, making them small camcorders (camera + recorders).

This article is under GNU FDL license and can be distributed without any previous authorization from the author. However the author´s name and all the URL´s (links) mentioned in the article and biography must be kept.

This article can also be accessed in portuguese language from the News Article section of page http://www.polomercantil.com.br/camera-digital.php

Roberto Sedycias works as IT consultant for http://www.polomercantil.com.br

http://www.articles-hub.com/Article/159115.html

New digital camera? Know how, where you can use it

Digital cameras were one of the hot gifts these holidays — the first one for some people, an upgrade for others. Cell-phone cameras are everywhere too, and sites like Flickr and Buzznet — not to mention photoblogs — make it easy for anyone to share the zillions of photos they're taking.

With all these cameras snapping around us, I started to wonder about the laws regarding using them. Where can you shoot? What can you shoot?

A blogger I know shot a picture in an office building. One of the tenants had boxes of medical records sitting around in an unlocked office, visible from the hall. He published a picture of the boxes, which started a little brouhaha: He didn't have permission from the building's landlord, someone said, so he wasn't allowed to take or publish the photos.

That turns out not to be the case.

What I discovered is that a lot of people have ideas — often very clear ones — of what is legal and what isn't, based on anything from common sense to wishful thinking to "I always heard…"

Trouble is, they aren't always right. If you've got a digital camera and like to shoot in public, it pays to know the real deal.

So I went looking for it. I checked with the Reporters Committee for Freedom of the Press and found its Photographers' Guide to Privacy.

The Missouri Bar has a terrific Journalists' Right of Privacy Primer by attorney Mark Sableman.

Bert P. Krages, an attorney in Portland, Ore., and author of the Legal Handbook for Photographers, has a short but excellent PDF document called The Photographer's Right.

I also had e-mail conversations with both Mssrs. Sableman and Krages (who were both careful to point out that they were only speaking in general terms, and not offering legal advice).

Finally, I got some background from the American Law Institute's A Concise Restatement of Torts on the Harvard Law website.

Of course, I'm not a lawyer; in this case I'm a researcher. But lemme tell you: All these sources jibed, which I take to be a good sign. Just don't take this as legal advice; it's one columnist's researched understanding of the law.

If you can see it, you can shoot it

Let's get the easy stuff out of the way. Aside from sensitive government buildings (e.g., military bases), if you're on public property you can photograph anything you like, including private property. There are some limits — using a zoom lens to shoot someone who has a reasonable expectation of privacy isn't covered — but no one can come charging out of a business and tell you not to take photos of the building, period.

Further, they cannot demand your camera or your digital media or film. Well, they can demand it, but you are under no obligation to give it to them. In fact, only an officer of the law or court can take it from you, and then only with a court order. And if they try or threaten you? They can be charged with theft or coercion, and you may even have civil recourse. Cool. (For details, see "The Photographer's Right.")

It gets better.

You can take photos any place that's open to the public, whether or not it's private property. A mall, for example, is open to the public. So are most office buildings (at least the lobbies). You don't need permission; if you have permission to enter, you have permission to shoot.

In fact, there are very few limits to what you're allowed to photograph. Separately, there are few limits to what you're allowed to publish. And the fact that they're separate issues — shooting and publishing — is important. We'll get to that in a moment.

You can take any photo that does not intrude upon or invade the privacy of a person, if that person has a reasonable expectation of privacy. Someone walking in a mall or on the street? Fair game. Someone standing in a corner, looking at his new Prozac prescription? No. Using a long lens to shoot someone in an apartment? No.

Note that the limits have nothing to do with where you are when you take the shots; it's all about the subject's expectation of privacy. You can be on private property (a mall or office-building lobby), or even be trespassing and still legally take pictures. Whether you can be someplace and whether you can take pictures are two completely separate issues.

Chances are you can publish it

Publishing photos has some different restraints, although they're civil, not criminal. Break one of these "rules" and, while you won't go to jail, you could find yourself on the short end of a lawsuit. (Although, according to the Reporters Committee for Freedom of the Press, "the subject's remedy usually will not include the ability to bar the publication of the picture.")

Revealing private facts about someone is a no-no. As the American Law Institute put it, "One who gives publicity to a matter concerning the private life of another is subject to liability to the other for invasion of his privacy, if the matter publicized is of a kind that A) would be highly offensive to a reasonable person, and B) is not of legitimate concern to the public."

Here the private property issue comes a bit more into play. Publishing a recognizable photo of someone at an AA meeting could be a problem, even if that meeting is open to the public. (An elected official, perhaps, but not of Joe Citizen.)

You also can find yourself in civil court if you publish a shot that places a person in a false light. That might be more of an issue with the caption than with the photo; running a shot of the mayor and his daughter labeled "Mayor meets with porn star" could land you in hot water. (Assuming his daughter isn't a porn star.)

Finally, you can't use someone's likeness for a purely commercial purpose — using a photo of someone in an ad, for example. That isn't to say you can't publish a photo in a commercial environment, such as a newspaper or a blog that accepts ads. If the photo is being used in a news or artistic sense as opposed to a commercial one you're OK.

Risk factors

The fact that taking a photo and publishing it are separate things might go against some folks' common sense.

Let's say you're banned by the local mall for taking photos there, but you go back anyway and take more. Now you're trespassing. But unless the photos you take violate someone's expectation of privacy, your taking photos isn't illegal — only being there.

That said, if you're arrested and convicted, a judge might use the fact that you were taking photos to increase the penalty, but shooting on private property isn't a crime in and of itself. As one lawyer told me, "I don't see why the act of trespass would turn something that occurs during the trespass into a tort if it wasn't one already."

There are some other risks to taking and publishing 'problematic' photos. But, as you'll see, they're easy to avoid.

Trespassing is an obvious problem. If you're not supposed to be someplace — you see a sign or you're told by the property owner, for example — you can get arrested. Sure, you might be able to publish the photos you take, but Web access from jail is limited. (Trespassing is almost always a misdemeanor, by the way.)

You might be charged with your state's variation of intrusion — using technology (e.g., a long lens, hidden camera, or parabolic microphone) — to access a place where the subject has an expectation of privacy.

Beyond trespass, the major risks you run are civil, not criminal. You can lose an invasion of privacy lawsuit if your photographs reveal private facts about a person that are offensive and not newsworthy when the person had a reasonable expectation of privacy. Ditto if they place the person in a false light, or inappropriately use the specific person's image for commercial purposes, e.g., stating that the mayor endorses a product by publishing a photo of him using it.

http://www.usatoday.com/tech/columnist/andrewkantor/2005-12-29-camera-laws_x.htm

Top Players In Digital Camera Market

Selecting a digital camera is definitely not an easy task with hundreds of brands available in the market. Before you decide to buy, you should take a look at the many features like optical quality, zoom, storage media and etc. These are only a few features among the many digital camera models to be compared. In terms of image quality, the amount of mega pixel resolution and the quality of the lens are the main factors that determine the sharpness of the pictures. And one of the best ways to know the quality and crispness of pictures is to see a printed picture.

As for image storage, there are many different kinds of storage media or flash memory cards available for digital cameras, which are rewritable chips that do not require power in order to retain the content. This makes it possible to take many photos without the fear of losing them before they are stored in CD-ROM or hard disk of the computer.

Surely, choosing a digital camera is not an easy task with so many models and range of mega pixels, features and different prices. Some of major brands available in the market are Argus, BenQ, Canon, Casio, Disney, Epson, Fujifilm, HP, JVC America, Kodak, Konica Minolta, Nikon, Olympus, Panasonic, Pentax, Polaroid, Ricoh, Samsung, Sanyo, Sony and Toshiba. However the most popular among them are Canon, Nikon, Sony, Olympus, and Kodak.

Sony`s digital cameras are among the most innovative and popular in the industry. The cameras range from tiny 2 mega pixel point & shoots to bulky 8+ mega pixel units. Some of Sony digital cameras that are selling fast are Cybershot N2, Cybershot S700, and Cybershot T20.

Canon is also ruling the market with its amazing array of models. They receive high ratings from consumers because of their impressive construction and top quality images. Canon produces a wide variety of cameras, ranging from small point and shoot ELPH series to the professional range of SLRs. The most popular ones are Canon PowerShot A460, PowerShot A710 IS and PowerShot A640.

Nikon is not far behind in the consumer digital market where it is one of the major players.The Coolpix line of cameras with its impressive D-series SLRs has made a splash in the camera scene. Take a look at the fast selling ones: Nikon D40, Coolpix S50 and Coolpix L12.

Kodak digital cameras are known for their simplicity and quality. The easiest to operate when compared to its competitors. The one-touch image downloading, emailing, and printing features have made this brand even more popular in the market. Take a look at few of the models in the market: Kodak EasyShare V1003, EasyShare V803 and Easyshare C653.

Among the other major brands is the Olympus that offers innovative features like the 10x optical zoom on the Ultra Zoom models and the weather-proof body of the Stylus series. Some of the popular ones are Olympus Stylus 550UZ, Stylus 760 and Stylus 770 SW.

Before you start shopping for a digital camera, it will be helpful to know the lingo. Understand what the salespeople are talking about when they drop these digital camera terms - Borderless, CCD, Compact Flash, Digital Zoom, DPI, Firmware, F-stop, Image Format, Grayscale, LCD Screen, Mega pixel, Memory Card, Memory Stick, Optical Zoom, Secure Digital, SLR and xD Picture Card. So, to be on the safer side, it is better to have the knowledge of these terms so that you don`t get cheated.

There is so much that goes into buying a digital camera. Wrestle all the details under control with the various brochures provided by the manufacturers before deciding to buy one for yourself.

This article is under GNU FDL license and can be distributed without any previous authorization from the author. However the author´s name and all the URL´s (links) mentioned in the article and biography must be kept.

This article can also be accessed in portuguese language from the News Article section of page http://www.polomercantil.com.br/camera-digital.php

Roberto Sedycias works as IT consultant for http://www.polomercantil.com.br

http://www.articles-hub.com/Article/159106.html

How To Buy Digital Cameras & Web Cameras

There are many good reasons to buy a digital camera or Web cam. Digital cameras let you take as many photos as you want without worrying about the cost of film or developing. You can also see the results of your efforts instantly, without waiting for photo developing. Digital cameras and Web cams also provide other benefits—they let you engage in videoconferencing, send photos as email attachments, or even help post images to the Web.

Before you choose a camera, it's important to research the camera models you are considering. Many people make the mistake of simply examining camera spec sheets, but there are a number of performance-related and subjective factors that a spec sheet will not convey. Below, we list some of the factors you should consider when selecting a digital camera or Web cam.

Digital Cameras.
Consider your needs before buying a digital camera. You don't need a powerful, high-end model if all you want is a simple point-and-shoot camera for posting snapshots to a Web page or exchanging images by email. A camera with a shooting resolution of 1,024 x 768 pixels will give you more than enough image quality for these tasks.

Resolution. A camera's resolution refers to the number of pixels (or single dots) it uses to create images. In general, resolution is often used to describe the sharpness and clarity of an image. Typically, the higher resolution a camera has, the better its images will be.
A digital camera with a megapixel resolution means it has a resolution of at least 1 million pixels. A camera with 2-megapixel quality has a resolution of approximately 2 million pixels, such as 1,600 x 1,200 pixels. Most two-megapixel cameras are capable of producing quality 5- x 7-inch photo prints. Currently, you can find many cameras with a 2-megapixel resolution for $200 to $300. Just a couple years ago, a 2-megapixel camera might have cost over $500.

If you want to print 8- x 10-inch photos, the camera’s resolution is important. Some high- quality 2-megapixel cameras can produce decent 8- x 10-inch prints. However, a 3-megapixel camera should print quality full-page prints with very few visible flaws. Cameras with three-megapixel quality are widely available for about $250 to $500.

You can also find cameras in higher resolutions, such as 4, 5, and 6 megapixels. It’s generally accepted that a 6-megapixel camera offers near film-quality results, however, such cameras are still very expensive. However, high-megapixel cameras come in handy if you have a printer capable of printing on larger paper or if you want to crop images and still print 8- x 10-inch photos.

Other important factors. You should consider much more than resolution. A quality 3-megapixel camera may very well produce better images than a cheap 4-megapixel camera. Read independent product reviews, such as those on this Web site, to learn about the image quality of specific camera models.

You should also consider what manual features you want. Just as you can choose between simple point-and-shoot film cameras and advanced film cameras with manual focus, you can choose between very basic digicams and digital cameras that contain a wealth of manual functions. If you buy a more advanced camera, look for one that has easy-to-use menus and controls, as well as a detailed users manual.

If you want a little bit of control over your images but don’t want to spend the money on an advanced model with features you will never use, look for a camera that includes WB (white balance) and EV (exposure value) control. Many cameras that cost less than $400 include such settings. Other features you might consider are a self-timer, macro mode, and an AF-assist (auto-focus assist) lamp.

You should also carefully consider the camera’s zoom capabilities. Many manufacturers print a combined-zoom figured on the packaging or on the body of the camera. Combined zoom includes both optical and digital zoom. Digital zoom is not a true zoom. As you apply more digital zoom, image quality deteriorates quickly. Optical zoom, on the other hand, maintains image quality and is a true zoom. For this reason, a camera with a combined zoom of only 4X (4X optical and 1X digital) will have better zoom power than a camera with a combined zoom of 20X (2X optical and 10X digital).

Many cameras let you capture video and sound. Some also double as Web cams with full videoconferencing capabilities. Many mid- or high-end digital cameras also have burst or continuous shooting modes, manual focus, flash synchs or hot shoes, a threaded lens, and various metering settings.

Also consider the camera’s design. Make sure it is comfortable to hold and that you can operate the controls easily. You should also consider batteries carefully. Cameras that use standard AA alkaline or NiMH (nickel-metal hydride) batteries are convenient because you can easily buy a new set of batteries if needed. However, they generally suffer from very short battery life. If you want to get more battery power before recharging batteries, look for a camera that uses a Li-Ion of InfoLithium battery pack. You will want a spare, though, because if you have battery problems, it will be harder to find a quick replacement. We prefer cameras that ship with a battery charger. Some manufacturers make the chargers an optional accessory.

For storage, most consumer models ship with a flash memory card. There are many types of memory cards, but you can only use cards that are compatible with your camera. For example, Canon cameras use CF (CompactFlash) cards, Sony cameras use MSes (Sony Memory Sticks), and today’s Olympus cameras use xD-Picture Cards (eXtreme Digital Picture Cards). (Older Olympus cameras used SMCs [SmartMedia Cards].) The most common types of flash memory cards for digital cameras are CF, SMC, xD, MMC (MultiMedia Card), SD (Secure Digital), and MS.

Web Cameras.
Like digital cameras, Web cams come in many varieties. In fact, Web cams are some of the most uniquely designed peripherals on the market. But before you buy a model based on its appearance, put it to the test. Many models have designs that leave them wobbling or tipping over whenever the monitor is bumped. Look for a Web cam that has a secure mounting device and a solid, heavy build. Otherwise, you'll spend an annoying amount of time readjusting it.

Nearly all Web cameras are capable of videoconferencing, video chat, posting images to Web pages, attaching video to e-mail, and capturing still images. Some models include an integrated shutter button to take still images away from the computer without having to use the keyboard. In addition, almost every Web cam on the market today uses a USB connection, making it easy to install. Many models also have a built-in microphone. If not, you'll have to provide your own.

Usually, the image quality that Web cams produce isn't anything to write home about. Yet, many models provide sharpness, color accuracy, and focus that are acceptable for videoconferencing. Look for a model that can handle varying lighting situations and hold the focus well into the background. Also, Web cams with automatic white balance are preferable.

Many models have top resolutions of 640 x 480 pixels. Others can reach better resolutions, but may do it with interpolation software. For Web cams, a higher resolution isn't as important for capturing video. Typically, a higher resolution means the camera will grab fewer fps (frames per second) of video, resulting in choppy, jerky motions. A camera with a resolution of 320 x 240 pixels for grabbing a smooth 30fps (television quality) of video is the norm.

Perhaps the best feature about Web cams is their price. Many name-brand cameras currently cost less than $40. In general, you should be able to find a Web cam with a quality performance, software bundle, and features for less than $60.

http://www.smartcomputing.com/editorial/articleht.asp?guid=zdahv6py&article=Articles/Hardware/2000/H0307/62h07.asp

Digital Camera & Web Camera Terms To Know

analog phone line— Also referred to as POTS (Plain Old Telephone Service), an analog phone line is a communication line that transmits information. Most homes use analog phone lines, making them popular for videoconferencing. A common problem with analog phone lines concerning videoconferencing is their limited bandwidth (which refers to how fast and how much information transmits over a line in a certain amount of time).

CCD (charge-coupled device)—An instrument with semiconductors arranged so that the output (electrical charge) from one semiconductor is the input of the next semiconductor. This type of array serves as the light-detecting component in many digital cameras, video cameras, and optical scanners. CCDs and CMOS (complementary metal-oxide semiconductor) components are the light-sensitive sensors used to capture digital images. Some manufacturers prefer CCDs while others use CMOS chips instead. CMOS chips are easier and less expensive to make and require less power than CCDs, but CMOS chips are vulnerable to damage from static electricity, and they often do not deliver the same image quality as CCDs.

CMOS (complementary metal-oxide semiconductor)—An electronic component used for RAM (random-access memory) and fast data switching. These semiconductors are made of two metal-oxide field effects transistors for high speed and low power use. However, static electricity can easily damage them. As mentioned in the definition for CCDs (charge-coupled devices), CMOS chips are easier and cheaper to make and require less power than CCDs, but they often do not deliver the same image quality as CCDs.

compression—Compression involves squeezing data down in size. This is an important factor for digital images because if images aren't compressed, a digital camera can only store a few of them in its memory. Some compression types negatively alter an image's quality. Most digital cameras combat this by offering multiple quality settings, making it possible for users to save many low-quality images or just a few high-quality ones. Some cameras also have raw modes that save shots without any compression at all. JPEG (Joint Photographic Experts Group) and FlashPix are two common compression formats used by digital cameras.

digital camera—In short, digital cameras use light-sensitive chips instead of film to capture still or moving images and store them as bits of information in internal or removable memory. Users can quickly transfer images to a computer for use in different applications. For example, users often attach digital images to e-mail messages, use them to enhance World Wide Web pages, or make them into colorful prints with a photo printer.

fps (frames per second)—A measurement of the speed at which a video switches from one frame to the next sequential frame to create the appearance of a moving image. Cameras with higher frame rates typically display video motion that is much smoother. Television-quality motion requires 30fps.

frame rate—A Web camera's frame rate refers to the number of frames (individual pictures) of video it captures per second. Frame rates are usually measured in fps (frames per second). Motion in videos with high frame rates appears more fluid than in videos with low frame rates. About 30fps is required to trick the human eye into seeing full motion. However, due to bandwidth limitations, many transmissions cannot reach that rate, resulting in the jerky, choppy motion that's sometimes associated with videoconferencing.

interpolation—Interpolation refers to the use of software to enhance the true resolution of a digital image and is often used with digital cameras and scanners. Through interpolation, the software copies pixels and pastes them among existing pixels to enhance the image's resolution.

JPEG (Joint Photographic Experts Group)—A color-image graphics compression format named for the committee that designed the standard image compression algorithm. Using compression, computer files can be altered to take up less storage space. In the JPEG image compression system, some data is sacrificed to achieve high rates of compression. Ratios of 100:1 or higher are possible, which means that a 100MB graphics file could potentially be reduced to 1MB in length. However, ratios over 10:1 or 20:1, depending on the particular image, begin to show noticeable image degradation. The more loss tolerated, the more the image can be compressed. Compression is achieved by dividing the picture into tiny pixel blocks, which are halved over and over until the ratio is achieved. JPEG files are supported by Web browsing applications, such as Netscape Navigator and Internet Explorer, and end with either the .JPG or .JPEG extensions.

lag time—Digital cameras typically require a few seconds from when users press the shutter button to when a camera stores the image into its memory; this is the camera's lag time. Also, most cameras need two to 10 seconds to convert an image into digital data, compress it, and store it as a file; this is known as recovery time.

LCD (liquid-crystal display)—The liquid-crystal display is a small monitor on the back of a digital camera that's used to preview and review images. The LCD also acts as a display to help adjust camera settings and scroll through menu options.

megapixel—This term refers to a digital camera feature that allows it to capture an image with a resolution of at least 1 million pixels, such as a resolution of 1,280 x 1,024 pixels. Two megapixel refers to a camera with a resolution of at least 2 million pixels. Three megapixel refers to a model with a resolution of at least 3 million pixels, such as 2,048 x 1,536 pixels.

RAM (random-access memory)—The standard type of memory that you can write data to or read data from. Information in RAM can be stored and accessed randomly, and therefore, more rapidly. RAM, which is also known as main memory, is the vital workspace of computing. The more RAM a system contains, the more information it can handle, and the more programs it can run at one time.

recovery time—Most digital cameras need two to 10 seconds to convert an image into digital data, compress it, and store it as a file; this is known as recovery time. Also, cameras typically require a few seconds from when users press the shutter button to when a camera stores the image into its memory; this is the camera's lag time.

resolution—The resolution of an image refers to its sharpness and clarity and reflects the number of pixels (a pixel is a picture element or a dot in an image) an image contains. The amount of bits used to make up each pixel determines how many colors display in an image. Put simply, a one-bit image appears monochrome, an eight-bit image produces a 256-color display, and a 24-bit image has more than 16 million colors. In general, the higher the resolution an image has, the better the image should be.

storing and transferring images—Most digital cameras use removable memory cards to store images, although a few still use internal memory. When a camera's internal memory is full, you must delete or transfer some images to a computer before you can take more photos. Removable cards are much more convenient because they insert directly into the camera and allow users to interchange them, much like rolls of film, whenever the camera's memory is full. Types of removable cards include 3.5-inch diskettes, PC Cards, and minicards, such as CompactFlash and SmartMedia. The use of removable cards and adapters has made transferring images easier and faster than connecting a camera to the computer's serial port and uploading the images. In addition, many cameras use a USB (Universal Serial Bus) connection for even faster transfer speeds.

TIFF (Tagged Image File Format)—A common way to store bit-mapped graphics images on both PCs and Macintosh computers. TIFF is a platform-independent format, which means a TIFF image created on a PC can be viewed on a Macintosh and vice versa. (Bit-map files, on the other hand, are a graphic format for the Windows environment.) The TIFF format was specifically designed for scanned images and is commonly used for that purpose. It also can be used in some applications to save images created on a computer. TIFF graphics can be color, grayscale, or black and white. The file extension for TIFF images is .TIF.

USB (Universal Serial Bus)—Until recently, most digital cameras transferred images to the computer using a serial cable. Now, more cameras are using the faster USB connection, a new type of external bus expected to replace parallel and serial ports. A USB connection has a maximum transfer speed of 12Mbps (megabits per second). A main advantage of USB over traditional ports is that it offers easy expandability; up to 127 devices can be daisy chained, far more than the number of devices supported by traditional ports. All USB devices support plug and play and hot swapping, as well. The computer automatically recognizes any USB device as soon as it's plugged in or added to the chain. Desktop computers that support USB typically have two four-pin USB ports: one for a keyboard and mouse daisy chain, the other to daisy chain all other USB devices. USB was introduced in computers shipped in 1997 and has received a boost from Windows 98, which offers better support for the standard than Windows 95.

video capture card—Some Web cameras use a video capture card to grab video and convert it into digital information. Other Web cams use a parallel port connection, eliminating the need for a video capture card; however, more Web cams are beginning to use a USB connection instead.

videoconferencing—The face-to-face communication via computers using Web cameras, microphones, speakers, and communication lines to transmit compressed audio and video data. Participants sit in front of a Web camera and speak into a microphone. As this occurs, the data compresses and transmits to another participant who receives the data by viewing the video on a computer screen and hearing audio via the speakers.

Web cameras—These devices, also known as Web cams or desktop digital video cameras, are small, they focus on one object (such as a person sitting at a computer), and they usually sit on top of a PC monitor. Web cams capture still images and video motion and then transmit this data for such purposes as videoconferencing, video e-mail, and enhancing World Wide Web pages.

http://www.smartcomputing.com/editorial/articleht.asp?guid=zdahv6py&article=Articles/Hardware/2000/H0307/64h07.asp

Choosing a Medium Format Camera

As editor of photo.net, I'm exposed to a constant stream of questions from people who can't decide what 35mm point and shoot or SLR camera to buy. Given that there is hardly any difference between modern Japanese 35mm cameras and yet folks are paralyzed with indecision, I sometimes wonder how it is that anyone comes to buy a medium format camera. Before you evaluate lens quality, brand reputation, included gizmos, electronic wizardry, or ease of renting accessories, you have to decide what size negatives you want!

Medium format cameras use 120 or 220 roll film, which is about 6 centimeters wide (2 and 1/4 inches). This size of roll film was introduced in 1898 by Kodak for its Folding Pocket KODAK Camera. It thus seems safe to say that the world has reached agreement on the proper height for a medium-format negative. On the other hand, nobody has ever agreed on the proper width. There are many standard widths for 120 camera frames: 645, 6x6, 6x7, 6x8, 6x9, 6x12, and 6x17. These numbers are ostensibly in centimeters although in practice a 6x6 camera such as a Hasselblad will expose a 56 x 56 mm frame.

My personal choice
I like 6x6. I find that I take better photographs when I park the camera on a tripod, look down onto the ground glass, and evaluate the composition as though I were looking at a finished photo. This is known as "waist-level viewing" and it is only really easy with a square-format camera.

How good would your pictures be if you had to decide on the frame molding shape, frame material, mat size, and mat color at the moment of exposure? Being forced to make all of these decisions would probably distract you from making images. Part of the workload of a 35mm or 4x5 photographer is deciding whether the subject would be better served by a horizontal or vertical image. Personally, I find that my photography improves if I'm not forced to think about cropping and image ratio at exposure time. I experiment with cropping and horizontal or vertical presentation at night with the square chromes on a light table.

Some of my favorite images have turned out to be square. This is especially true when the photograph is of a pattern or a collection of objects. The viewer can see the pattern better if he or she is not hammered into thinking in one direction or another by a rectangular frame.

The folks who make Hasselblad argue eloquently for the square format in The Medium Format Advantage. One of their arguments is that you shouldn't lug around the weight of a lens that you aren't using. Lenses project circular image disks. If you park a rectangular section of film behind the lens, you're wasting much of this "circle of good definition". If you expose circular frames of film, you're wasting much of the film. If you expose square frames of film that fit exactly inside the image circle, you're not wasting any film and you're wasting as little image circle as possible. Thus the lenses for a Hasselblad (6x6) are much lighter than the lenses for any 6x7 camera.

Which 6x6 camera is best? If you're rich and strong, I like the Rollei 6008 single-lens reflex system. If you are traveling and want something light, the Mamiya 6 rangefinder system is wonderful. If you're poor, you might consider a twin-lens reflex such as the Yashica 124 or Mamiya.

In fairness to 6x6 detractors, I'll show this photograph of Boston from the banks of the Charles River by MIT. They would say "look at all that wasted space at the bottom of the frame". The truth of the matter is that this is a terrible picture, ruined by the lack of any foreground subject. It would have been a waste of film even with my Fuji 617 camera. If you can't fill a 6x6 frame with interesting stuff then you won't have a good picture. If you are able to fill a rectangle's worth with interesting stuff, then you won't mind cropping off a bit of film.

My other personal choice
The 645 format is the smallest, lightest, and cheapest roll-film design. Negatives are a little squatter than the standard 35mm frame (24x36mm) and therefore full-frame printing on standard paper sizes such as 8x10 need not require a cropping decision. What you get is a sharper deeper negative that enlarges beyond 11x14 with more grace and is easier to handle if you do your own darkroom work. Sadly, it is also vastly more expensive and difficult to scan than a 35mm neg, so keep that in mind if you want to stand tall on the Web with lots of photos.

Fuji has done great things to promote this format. They make 645 lenses that are just as good as Hasselblad's 6x6 lenses. They charge less than half the price. Then they throw in a perfectly good body behind the lens for free! Sometimes Fuji puts a meter in the body, something that apparently costs 'Blad about $5,000 extra. Sometimes Fuji puts in an autofocus mechanism (they were the first to do so in the medium-format world). Sometimes Fuji adds a wide-to-normal zoom lens! Whatever they do, the integrated camera, body, meter, and lens costs about as much as a Hasselblad or Rollei film back.

The most collectible Fuji 645 is the old folding model with a 75mm lens. I have a GS645W from this series that takes great wide-angle pictures with a 45/5.6 lens (equivalent to 28mm in a 35mm system). The modern Fujis that you can buy from the photo.net recommended retailers operate much like 35mm point-and-shoot cameras. (See Medium Format Digest's Fuji section for more on these cameras.)

If you want something with the flexibility and features of a standard Canon or Nikon SLR, consider the Pentax 645N autofocus system. If you feel compelled to pay double or triple Pentax's lens prices, the Contax AF 645 system is for you. The lenses have a Zeiss brand name, in which I'd put little stock, especially given that they're probably made in Japan by Kyocera/Yashica. What is intriguing is that the lenses contain Canon EOS-style ultrasonic motors. Pentax uses the ancient Minolta/Nikon-style screwdriver-blade-in-the-body method of autofocus.

6x7
Photographers on portrait assignment for magazines often use the 6x7 format. The weight isn't a problem since they have assistants, rolling carts, and advance planning.

If you don't have a flotilla of assistants, your only real options are the Fuji rangefinders (very cheap but no meter) and Mamiya 7 rangefinder (sort of cheap if you buy it in Asia; meter in the body and interchangeable lenses including a delicious super-wide lens). If you want to pretend to be a magazine portrait photographer, invest in the unbelievably heavy and clunky Mamiya RB or RZ67 system (see the archived threads in the Medium Format Digest). If you want to pretend to be a starving artistic nature photographer, throw a Pentax 6x7 II system into your beat-up full-size van. This is a huge 4-pound SLR body that includes a prism the result is what looks like an old Nikon on steroids. Lenses are sensibly priced.

6x8
Fuji makes a very interesting GX 680 III camera. It is similar in size and weight to the huge Mamiya RB/RZ system but you get modern electronics and the same perspective controls that you'd find on the front standard of a view camera.

6x9
Fuji makes a rangefinders that are remarkably cheap, light, compact, and high quality (as of 1999, you can choose between 65mm and 90mm lenses). Regrettably they don't include a meter.

6x12
6x12 is a panoramic format that is interesting because it is the largest hunk of roll film that will fit into a standard 4x5 enlarger. If your ambitions stretch to larger formats, you'll be limited to contact prints, digital imaging, or professional photo labs.

If you already own a 4x5 view camera, a cheap way to get into 6x12 is with a roll-film back. You're saved the hassle of loading film holders but the other operational annyances of the view camera will still slow you down. On the plus side, even with the very cheapest view camera and 6x12 back you get perspective control, something that will cost you northwards of $8000 in a Linhof 612 PC outfit (includes one lens, a Schneider 58mm XL that costs $1,213 in a view camera shutter).

With a rotating lens on a 612 camera body, you can get some very interesting photos. The Noblex is the most common example of the breed, producing a 146-degree photo free of distortion and light falloff.

6x17
If it pains you to take more than four pictures on a roll of film, a 6x17 camera is for you. Check my Fuji G617 review for some sample images. The right camera to buy in this size is a used Fuji G617 (the old one without interchangeable lenses). I got mine for $2200 in flawless condition. The things that it really could use are perspective control and the ability to focus closer. What the market has delivered instead are 617 cameras with interchangeable lenses and breathtaking price tags. For the same price, you could get a G617 and a 4x5 or 5x7 view camera system for the times when you needed a different focal length, a closer focus ability, or perspective control.

More

• Internet's biggest, best, and best-archived discussion of medium-format cameras is Medium Format Digest

Inspiration
I'm going to try to keep tossing in photos here that show the advantages of various medium format cameras and image dimensions.

http://www.photo.net/photo/medium-format/choosing