DIGITAL CAMERAS

A Guide to Purchase a Digital camera

By: Roberto Sedycias

hotographic camera became a desired consumer item since it became handheld many years ago. As it became digital with no need for film processing, digital camera became even more popular and it is now considered one of the most wanted optical/electronic consumer products.

However buying a digital cameras may be a bit difficult due to the many brands and models being offered. After all there are so many features, one has to be sure of his needs in picking the right digital digital cameras. The following tips might of some help:

1 - Price range: It is recommended that you establish a price range you are willing to pay for your new digital camera. Prices can start from bellow a hundred up to thousands of dollars.

2 - Features: Within the price range previously established, check the features available in digital cameras. Make sure it will meet your requirements for your personal or professional goals. You may find features such as zoom, automatic functions, special effects, black & white images, video recording capability and others.

3 - Battery life: Depending upon the places you go, charging the camera`s battery may not be possible. So make sure the battery life will last long enough during your outdoor activities. Also it may be a good idea to have some extra rechargeable batteries, so that that you won`t have to stop using the camera, while the original batteries are being charged.

4 -Digital Memory Storage: Digital photographs are stored in the digital camera`s memory. Most digital cameras have built in memory, but it will accept memory card as well, to increase its storage capability. Depending upon the picture resolution, a user can take hundreds of shots, before it exceeds the memory storage.

5 - Image Resolution: Also known as pixel resolution, this is one of the most talked about features in digital cameras. Although 2.0 mega pixels will deliver good photos for any personal and emailing purposes, nowadays digital cameras with 8.0 and above mega pixels (million of pixels) have become a standard feature. The higher the mega pixel resolution, the better it will look the pictures in larger prints. For those thinking about image enlargement, high mega pixel resolution is a must.

6 - Lens: Beware that the zoom feature may be of two kinds: optical and digital. Optical zoom relies on the lens magnification and delivers a good, sharp and clear image. On the other hand, digital zoom is the magnifying of the digital image and produces a less sharp, grainy image. So make sure that the digital camera offers some optical zoom capability. Also look for lens auto focus and image stabilization features.

7 - LCD: LCD screen is a standard feature in every digital camera, and it works for framing the shot beforehand and viewing it afterwards. Look for LCD screen size 2 inches and above for better clear images.

8 - Online Stores: Whenever looking for the best deals in digital cameras, take a look at some trusted internet stores. Since prices are posted in web sites, people may find very easy to compare them, and get the best deals. Also take a look at some auction sites, for new and used digital cameras.

Digital camera has definitely become a very popular consumer product. The easy of taking shots and emailing to friends have really made this item an absolute must-have kind of product. I guess one could say that people found in digital cameras the perfect tool to preserve special moments by sharing digital photos with loved ones, around this ever growing wide web world.

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 has a bachelor degree in Business Administration and over 20 years experience in systems analysis and computer programming. Currently working as IT consultant for http://www.polomercantil.com.br

by digital camera knowladge

Global Position system

Global Positioning System

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"GPS" redirects here. For other similar systems, see Global Navigation Satellite System. For other uses of "GPS", see GPS (disambiguation).

For a generally accessible and less technical introduction to the topic, see Introduction to the Global Positioning System.

Artist's conception of GPS satellite in orbit

Civilian GPS receiver ("GPS navigation device") in a marine application.

Automotive navigation system in a taxicab.

The Global Positioning System (GPS) is a Global Navigation Satellite System (GNSS) developed by the United States Department of Defense. It is the only fully functional GNSS in the world. It uses a constellation of between 24 and 32 Medium Earth Orbit satellites that transmit precise microwave signals, that enable GPS receivers to determine their current location, the time, and their velocity. Its official name is NAVSTAR-GPS. Although NAVSTAR-GPS is not an acronym,^[1] a few backronyms have been created for it.^[2] The GPS satellite constellation is managed by the United States Air Force 50th Space Wing. GPS is often used by civilians as a navigation system.

Similar satellite navigation systems include the Russian GLONASS (incomplete as of 2008), the upcoming European Galileo positioning system, the proposed COMPASS navigation system of China, IRNSS of India, and DORIS of France.

After Korean Air Lines Flight 007 was shot down in 1983 after straying into the USSR's prohibited airspace,^[3] President Ronald Reagan issued a directive making GPS freely available for civilian use as a common good.^[4] Since then, GPS has become a widely used aid to navigation worldwide, and a useful tool for map-making, land surveying, commerce, scientific uses, and hobbies such as geocaching. Also, the precise time reference is used in many applications including scientific study of earthquakes, and synchronization of telecommunications networks.

The first satellite navigation system, Transit, used by the United States Navy, was first successfully tested in 1960. Using a constellation of five satellites, it could provide a navigational fix approximately once per hour. In 1967, the U.S. Navy developed the Timation satellite which proved the ability to place accurate clocks in space, a technology that GPS relies upon. In the 1970s, the ground-based Omega Navigation System, based on signal phase comparison, became the first worldwide radio navigation system. The design of GPS is based partly on similar ground-based radio navigation systems, such as LORAN and the Decca Navigator developed in the early 1940s, and used during World War II. Additional inspiration for the GPS came when the Soviet Union launched the first Sputnik in 1957. A team of U.S. scientists led by Dr. Richard B. Kershner were monitoring Sputnik's radio transmissions. They discovered that, because of the Doppler effect, the frequency of the signal being transmitted by Sputnik was higher as the satellite approached, and lower as it continued away from them. They realized that since they knew their exact location on the globe, they could pinpoint where the satellite was along its orbit by measuring the Doppler distortion.