What you need to know to buy a smartphone
Ever wonder what 'capacitive touchscreen', 'MicroSD' and 'HSPA+' mean? We provide real definitions for the specifications most commonly used to describe what's under the hood in today's smartphones.
Smartphone specifications explained: Touchscreens
Smartphone touchscreens allow the user to interact directly with the phone's interface and operating system. These days, two main types of touchscreens are used in smartphones: resistive and capacitive. Resistive touchscreens contain two layers of conductive material with a small gap between them. When your finger depresses a point on the screen, the two layers meet and form a circuit at that location. The information from that circuit then goes to the phone's processor.
Capacitive touchscreens often appear in higher-end smartphones like the Motorola Milestone. These screens usually consist of a layer of glass coated with a transparent conductor like indium tin oxide. The human body also conducts electricity, so when your finger touches the coating on the glass, it creates an interruption in the screen's electrostatic field. The phone's processor then detects the location of that interruption.
Smartphone specifications explained: Battery
Many of today's mobile phones use lithium-ion batteries; lithium is the chemical inside the battery cell that migrates to the cathode of the battery, releasing an electrical charge. Lithium-ion batteries are rechargeable and last two to three times longer than alkaline batteries.
Larger phones tend to have 1500mAH lithium-ion batteries, while most smaller phones have around 1400mAH. (The current capacity of a mobile phone battery is measured in milliampere-hours, or mAH.) Most of your battery's power goes to powering your screen; that's why phones with larger screens use 1500mAH batteries.
The battery that accompanies a phone is usually satisfactory for that model, but if you spend long periods away from electrical outlets, it's a good idea to buy a lithium-ion battery with a larger capacity than the one that comes with your phone. Note that talk and standby times vary depending on the number of apps the phone is running, the screen brightness, whether you have Wi-Fi/GPS or 3G turned on, and other factors.
Smartphone specifications explained: Camera
Is there much practical difference in image quality between a picture shot with an 8Mp camera and one taken with a 5Mp camera? The megapixel count reflects the size of the camera's sensor - a small device inside the phone that converts an optical image into an electronic signal. The higher the pixel count, the higher the resolution of your photos. But you'll probably view most of your photos on your phone's display or on a PC, where the two resolutions are typically indistinguishable. If you plan on printing your photos, however, a higher megapixel count will make a difference.
As is true with point-and-shoot and digital SLR cameras, more megapixels doesn't automatically mean better image quality. Other factors that affect image quality include the quality of the camera lens (the Nokia www.nokia.co.uk N-Series phones, for instance, ship with lenses made by Carl Zeiss, a company that also makes lenses for high-end digital SLRs), the accuracy of the camera's autofocus features, and the camera's shutter speed (this is especially important if you're shooting a fast-moving subject). Shooting modes for various light environments (low-light indoors, evening, nighttime, etc.) can also help improve image quality.
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