Digital cameras can be perplexing to many beginners. When shopping for a digital camera it is very likely that you will encounter terms like white balance, pixel, ppi and dpi mean and how they affect image and print quality.
You may be probably expected to know the difference between things like optical zoom and digital zoom as well as the advantages and disadvantages between storage formats such as Compact Flash (CF), Microdrives, Sony Memory Stick, Secure Digital (SD), Multimedia and camera interface technologies such as USB 1.1, USB 2.0 and Firewire IEEE 1394. Lets make things simple and go to the basic things you actually need to know.
Pixels
A pixel is a abbreviation of the term PIcture ELement. Digital images are basically made up of small squares, just like a tile mosaic on your kitchen or bathroom wall. Are the more pixels the better? For viewing on the internet, resolutions of 640 X 480 is enough. For a typical 4R photo, you need a resolution of 1200 X 1800.
Difference Between Digital Zoom and Optical Zoom
Most cameras have both optical zoom and digital zoom functions. Optical zoom works just like a zoom lens on a traditional film camera. The lens changes focal length and magnification as it is zoomed. Image quality is high through the zoom range. Digital zoom simply crops the image to a smaller size and enlarges the cropped portion to fill the frame again. Digital zoom always results in a consider loss of quality.
The Storage Wars
There are quite a few different memory cards used in different digital cameras.
Compact Flash (CF) – The original memory card. Somewhat larger than the others, but used on all high end DSLRs. Available in capacities up to 2GB.
Secure Digital (SD) – Very small – about 24mm x 32mm and 2mm thick. SD cards have a built in write-protect switch to prevent any unintentional removal and certain encryption capabilities. This may be of very little interest for most digital camera owners.
Multimedia – Same size as SD but with less features and no encryption capability. There are some that can be used in some SD cameras but they are not 100% compatible with SD cards in all applications.
Memory Stick – It is introduced by Sony and used only by Sony cameras.
XD – Developed and used by Fuji, Olympus and Toshiba – even smaller than SD. 20mm x 25mm by 1.7mm thick
There's really no reason to pick a camera with one brand over another unless you have multiple cameras or other devices which may also use the same memory cards. Then it is more convenient if they can share the same cards.
Buying a Digital Camera
Some magazines advertise cameras at low prices yet they charge high shipping cost or they may tell you it is out of stock. Of course they have a more expensive model for you. Shop for cameras only from reputable dealers. At least they probably have a more responsive customer service.