Friday, February 4, 2011

Buying a Digital Camera

Getting started

Buying a digital camera can be disorienting. There are hundreds of cameras available at many different types of retail outlets (online and in traditional stores), with prices ranging from $75 to several thousand dollars. Some cameras are small enough to fit in a shirt pocket. Others are large and can weigh up to two pounds. Some are easy to use. Others look like you need an engineering degree to operate them. And almost all are advertised with abbreviations that can be cryptic and confusing for the novice. In this digital camera guide, we aim to help you overcome some of this confusion.

What is a digital camera?

The first step is to understand what a digital camera is. With a film camera, an image is formed by collecting light from a particular scene or subject and focusing on film, which reacts chemically when struck by light and is said to "capture" the image. What makes a camera "digital" is that, instead of film, it has an image sensor that reacts to light by sending out electrical signals.

The camera takes the information from the image sensor and processes and stores it as a collection of pixels in a digital file, usually on a memory card inside the camera. Although the actual process is more complex than that, in essence it is how a digital photo image is made. It's essentially made up of thousands and thousands of tiny dots, or pixels.

What are megapixels?

When you collect a million pixels, you have a megapixel. The number of megapixels tells you how many pixels the image file has. A camera that captures 8 million pixels, for example, is called an 8-megapixel camera. The number of megapixels a camera features can also help to determine the size photos you can print or the amount of cropping you can do. For example, a 4-megapixel camera may be enough for snapshots, but if you want to print poster-size images or crop heavily, 8 megapixels (or greater) is more suitable.

A 6-megapixel camera might be all you'll need because higher resolution doesn't necessarily produce better prints. Lenses and other factors affect quality too. But most cameras today have at least 10-megapixel sensors. The size of the sensor, and the size of each individual image sensor element, which corresponds to pixels, can affect photo quality. But remember, the number of megapixels alone doesn't determine the quality of a digital camera's images.

Types of digital cameras

Our Ratings are divided into two main categories: Basic cameras, are simple point-and-shoots with just the features needed for routine shots, and advanced cameras, which are feature-laden cameras that include sophisticated point-and-shoot and models that let you chance lenses. Note that all point-and-shoots, whether basic or advanced, include cameras with lenses built into the camera (that is, non-removable).

Our basic camera category is divided into three subcategories: subcompacts, compacts and superzooms.

Subcompacts fit in a pocket, are lightweight but generally have few manual controls. A few include nontelescoping zoom lenses, and others have zooms as high as 14x. Compacts are a bit larger, and often have more manual controls than subcompacts. They can also be among the most inexpensive cameras available.

Superzooms offer 15x or greater zoom, with some recent models including optical zooms as great as 30x. Like compacts, superzooms often, though not always, include manual controls. They're also among the more expensive basic cameras.

Our advanced camera category is also divided into three subcategories: advanced point-and-shoots, SLR-like and SLRs.

Advanced point-and-shoots have a nondetachable lens but differ from basic models because they have lots of manual controls, a hot shoe for an external flash, and support for RAW files. It's the lightest advanced type. SLR-like models have interchangeable lenses, but they lack a through-the-lens viewfinder. They're smaller and lighter than an SLR but usually larger than a point-and-shoot. SLRs have the most features, with interchangeable lenses and the largest sensors for the best image quality in low light, and a through-the lens viewfinder. Controls are extensive. They're also the heaviest, most expensive cameras.

Next steps

After you consider the type of camera you want and the number of megapixels you need, but before you dive into specific models, be sure to check out our brand profiles, which outline many of the most popular camera product lines and their respective character traits.

Recommendations (available to subscribers) for the models that have the best performance and image quality, including scores for how models capture regular, low-life and flash photos. If you're interested in how well a camera captures video, consider the video quality score. And to see which models respond the quickest, consider the response time score, which is an overall speed judgment, including start-up time and the shutter delay for the first and later shots. In most cases, our

(available to subscribers) for the models that have the best performance and image quality, including scores for how models capture regular, low-life and flash photos. If you're interested in how well a camera captures video, consider the video quality score. And to see which models respond the quickest, consider the response time score, which is an overall speed judgment, including start-up time and the shutter delay for the first and later shots. In most cases, our

Ratings found that point-and-shoot cameras take decent snapshots. So, look through our Ratings for specific features that are important to you. For example, if you want a point-and-shoot that has a better LCD than others, look for a model with a Very Good LCD quality score. Or, if you want a model that includes a touch-screen LCD, look for that in our

found that point-and-shoot cameras take decent snapshots. So, look through our Ratings for specific features that are important to you. For example, if you want a point-and-shoot that has a better LCD than others, look for a model with a Very Good LCD quality score. Or, if you want a model that includes a touch-screen LCD, look for that in our

Ratings. There are also scores for how well a camera handles shake, which can cause blurry photos, its controls, and versatility.

. There are also scores for how well a camera handles shake, which can cause blurry photos, its controls, and versatility.

What you'll spend

For many, price is a major factor when buying a camera. In general, look to pay the following for the type of camera you're looking to buy:

When you're ready to buy, consider where you will make your purchase. Although some walk-in stores, such as photo-specialty camera shops, might have knowledgeable salespeople, you can't rely entirely on the staff of walk-in stores to assist you in your purchase. Use the internet and our Ratings for information before buying. Also, if you decide to purchase at a traditional retail store, forgo the extended warranty because digital cameras have been among the most reliable products in our surveys.

Many respondents in our surveys found online shopping to be a more satisfying shopping experience than walk-in-store shopping. Most walk-in retailers offer either low prices or wide selection. But some online retailers offer both. But be cautious of very low prices and verify that the camera isn't refurbished or gray market (diverted from other retailers or not meant for sale in the U.S.).

Types


Basic cameras
Advanced cameras

Features

Digital camera features vary greatly from model to model. Some might be essential to you, while others might be of use only for highly specialized applications. Before you buy, consider the following features, which are included on most digital cameras.

Exposure modes

Most digital cameras, including SLRs, are highly automated, with features such as automatic exposure control, which manages the shutter speed and aperture according to the available light. In that mode, the camera generally handles setting ISO and autofocus too. But there are other program modes that allow you to control specific settings, including shutter priority, aperture priority, and special scene modes. Some cameras include full manual controls, which let you set shutter speed and aperture.

Zoom lenses

This type of lens, which is actually made up of several different lenses or lens elements, allows you to vary the focal length. That provides you with flexibility in framing shots and closes the distance between you and your subject, which is ideal if you want to quickly switch to a close shot. The typical 3x zoom on mainstream cameras goes from a moderately wide-angle view (35mm) to moderate telephoto (105mm). You can find cameras with extended zoom ranges between 5x and 30x, giving you added versatility. If you want a greater view angle for more panoramic landscapes or group portraits, look for cameras with a wide-angle end of the zoom range as low as 28 or 24mm.

One common feature of zoom lenses is that they generally protrude from the camera when you turn it on. But some subcompacts and a few compacts and superzooms have nontelescoping lenses. On larger compacts or superzooms, you might also find a manual focus ring similar to the one on an SLR lens, although manual focusing on a point-and-shoot works differently than that on an SLR.

Optical zooms are much better than digital zooms, which merely magnify the center of the frame without actually increasing picture detail. Almost all point-and-shoot digital cameras include zoom lenses. SLRs, which can use interchangeable lenses, often ship with a zoom lens, but also use prime or nonzoom lenses.

Image stabilization

More and more cameras, including many with powerful lenses, now come with an image stabilizer, a device that compensates for handheld camera shake. Often, the IS device lets you shoot with a slower shutter speed than you otherwise could without producing blur due to hand shake (although it won't compensate for a subject's motion). Optical (in the lens) and mechanical (in the camera body) image stabilizers are the best types to use, although some cameras include simulated stabilization.

In SLRs, some brands include mechanical stabilizers, which can use IS with every lens. But some SLR brands only include optical IS in telephoto or long zoom lenses, which are the ones that need it most. The optical-based IS generally produces better results than mechanical-based IS. But you won't have IS on every lens because it's not built into the camera body. Image stabilization is a feature you should look for, especially if the camera has an optical zoom greater than 3x.

Face detection & ¿Smart Camera' features

This digital camera feature attempts to find a face in the image to set focus, exposure, and color balance so that faces appear in focus and well exposed. When we've tried it, we found that it usually worked well. In some cameras, you have to turn on the feature. In others, it's enabled at the factory, but can be turned off. Other types or variants of face detection are beginning to appear in newer cameras too, such as a smile shutter mode, which shoots a photo of the subject when a subject smiles. Other types include blink warning, which alerts you to shots in which a subject might have blinked, and intelligent ISO.

Focus

In addition to being able to automatically set exposure, digital cameras automatically adjust the focus of the lens with autofocus features. But more advanced cameras include additional focusing functions. Be sure to look carefully at the types of additional features available on your camera, including manual focus. On SLRs, look for the number of AF points they have and what types of AF modes are available. SLRs include additional types of AF (often called dynamic AF) that groups focus points into a field to more accurately track moving subjects.

Shooting modes

Most cameras have three options for shooting still images: single image, burst mode, and self-timer. The burst mode allows you fire off a series of shots quickly, for several, dozens, and sometimes scores of shots. Some SLRs can shoot more than a hundred shots in a burst, and do so very quickly (measured in frames per second, or fps). Some newer advanced point-and-shoots are also able to capture many shots per second. As the name implies, the self-timer mode provides a delay between the moment the shutter button is pressed and the photo is captured. Some cameras let you set how long this delay is and the number of shots you can take.

Playback modes

All digital cameras can review images on the LCD, along with exposure and other information embedded in the image file. So, you can quickly see what the image actually looks like, and delete it if you don't like it. Many cameras have automatic orientation features that turn the photo vertically or horizontally to correspond to how you shot the photo. When reviewing, you can use the zoom control to magnify portions of the image file. The LCD screen is also where you would access the camera's menu system in order to change various settings and access features. A few types of digital cameras include either touch-screen LCDs or LCDs that swivel. The best LCDs also don't change in color or tone (often called solarizing) when viewed at an angle, although we don't test for that. Selected models include slideshow features, and some even let you play music or create a multimedia slideshow.

ISO

This setting expresses how sensitive the sensor is to light. Many cameras allow you to set various ISO settings (anywhere from ISO 100 to ISO 1600, although some ranges can be even greater, particularly on SLRs). The advantage in being able to set a higher ISO is that you can then have more flexibility in adjusting either the aperture or shutter speed. For example, if you need to shoot an image at 1/250 of a second in order to "freeze" the action, but you have only enough light for a shutter speed of a 1/125 of a second, one option is to change the aperture to let more light in. But if you're already at the widest aperture, you can instead increase the ISO from 100 ISO to 400 ISO, and you should be able to set the higher shutter speed.

But high ISO settings on point-and-shoot cameras, which have smaller sensors than SLRs, often suffer from image noise, which will make your photos look grainy and degrade image quality. So, even though point-and-shoots include ISOs up to 3200 or higher, you may be disappointed in the results. There is also concern about the relationship between high megapixel counts and sensor sizes. The more megapixels manufacturers cram onto the same-sized sensor, the more visual flaws can appear in the images.

LCD viewers

Although optical viewfinders were once ubiquitous on cameras, hardly any subcompacts or compacts include them anymore. The reason is that they've been replaced by larger, sharper color LCD viewers. Some are now as large as 3.5 inches. These displays are accurate in framing the actual image you get--better than most optical viewfinders--but they might be hard to see in bright sunlight. This live-view functionality, available in point-and-shoot for years, has also been appearing on more and more SLRs, which have traditionally used the LCDs for only playing back or reviewing images. A camera with an optical and an LCD viewfinder is more versatile, especially when you shoot in bright light or need to conserve battery power. Also, select point-and-shoots and SLRs include swiveling displays, which are helpful for taking hard-to-reach shots.

Flash

Available on almost every digital camera, a flash (or strobe) allows you to illuminate subjects by using a short burst of light. Nearly all have auto-flash modes, a setting that will automatically fire a flash whenever the camera senses there isn't enough illumination for a correct exposure. Most include other flash modes, including red-eye reduction mode, which minimizes a common flash camera problem (although you can also fix this in an image-editing program when the image is stored on your computer). There are primarily two types of flashes associated with consumer-level cameras: A built-in (onboard or, in some cases, pop up) strobe is generally positioned directly above or diagonally above the lens. An external strobe, sold separately as an accessory, fits into a camera's hot shoe, which lets you attach this accessory on to an advanced point-and-shoot, SLR-like model, or SLR. Many cameras include a number of flash modes that allow you to alter the type of flash or the strength of the illumination.

Image file formats

The most commonly used file format is the JPEG, a compressed image format that allows you to use the file for a number of different applications, such as printing photos, but also for using on Web pages and emailing as attachments. Advanced point-and-shoots and all SLR-likes and SLRs can also capture images in a file format commonly known as RAW. This format is most often uncompressed and the image isn't processed inside the camera, as with JPEG files. RAW files can yield the best quality images and give you the most flexibility when manipulating the photos with software.

Memory cards

Instead of film, nearly all digital cameras record their shots and store them on flash-memory cards, although occasional models also have had onboard flash-memory capacities greater than 1 GB. SecureDigital (SD) is the most widely used format. Other memory cards used include Compact Flash (CF), mostly on SLRs, Memory Stick Duo and xD. Although those storage cards were once quite expensive, they have recently dropped significantly in price. New cameras can also accept special, higher capacity versions of SD cards, such as SDHC and the latest, SDXC, a format that allows memory-card manufacturers to produce cards with capacities as large as 2 terabytes.

Connections

To save images, you transfer them to a computer, typically by connecting the camera to the computer's USB or FireWire port, or inserting the memory card into a special reader. (Many computers now have built-in card readers.) Cameras can also be connected to printers, or you can insert the memory cards directly into select printers. Both options allow you to print photos without the need to transfer them to a computer. Most cameras also include a video output that lets you view images on your TV. Some even include an HDMI output (on the camera body or camera dock) that can be attached to an HDTV. But the cords and docks might cost extra.

Video

Basic point-and-shoots have been able to capture video for many years, but SLRs have only recently included this feature. Most cameras include HD-resolution video, although some still capture in standard definition, which may not look as sharp on an HDTV. Some models with HD video quality are good enough to avoid the cost and inconvenience of a separate camcorder. One convenient video feature many cameras now include is a dedicated video button, which lets you quickly record video when you're shooting still images. Also, if you're buying a basic or advanced point-and-shoot, check to see whether the camera can zoom while capturing video. Not all models can.

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