Image Sensor

There are two different kind of image sensors used in digital cameras:
CCD (Charged Coupled Device) and the CMOS (Complementary Metal Oxide Sensor).
Both types of image sensors are light sensitive chips used for image gathering.
The CCD is the most used one in digital cameras today.
The image sensor is positioned in the digital camera where the film would normally be. When the photograph is captured the information is stored in the digital camera's memory.

Resolution

For digital cameras the resolution is usually expressed as a matrix of horizontal by vertical pixels. A resolution of 640x480 means the digital camera produces images that consists of 640 horizontal pixels by 480 vertical pixels.

Images Capacity

Number of images (pictures) that can be stored depending on the image quality mode.

Compression

There are several formats used to compress an image: JPEG, TIFF or others.
Image compression plays a big part in how many images can be stored per MB of memory.
JPEG stands for "Joint Photographic Experts Group." A standardized image compression format developed by the Joint Photographic Experts Group.
TIFF stands for "Tagged Image File Format."
Digital cameras from Kodak have their own propietory format.
JPEG and TIFF images can be read by a wide variety of imaging software programs. For the other formats you need special camera driver software to view them on a computer.

Lens

Most manufacturers list a combination of f-Number (aperture) and focal length under this category.

·         f-Number
A number that indicates the size of the lens opening (aperture) on an adjustable camera. The common f-numbers are f/1.4, f/2, f/2.8, f/4, f/5.6, f/8, f/11, f/16, and f/22. The larger the f-number, the smaller the lens opening. In this series, f/1.4 is the largest lens opening and f/22 is the smallest. Also called f-stops, they work in conjunction with shutter speeds to indicate exposure settings.
Each number represents an aperture that admits half as much light as the preceding one. Thus, f/16 lets in half as much light as a lens opened to f/11.

·         Focal length
The distance (in millimeters) between the image sensor and the optical center of the lens when the lens is focused on infinity.

·         Example
5 mm (equivalent to 36mm on a 35mm camera)
means the focal length of the digital camera is 5mm, which is equivalent to a focal length of 36mm in a convential camera that uses 35mm film.

Focus

Adjustment of the focal length setting on a lens to define the subject sharply.
Most digital cameras have a fixed-focal-length lens with closeup or macro setting. Some have zoom lenses or dual-focal-length lenses.

Focus Range

The range within a camera is able to focus on the selected picture.
Usually the focus range is listed for normal mode and/or macro mode.

Memory/Storage

Built-in

 The image storage method use two different techniques:
Built-in (internal) memory and removable memory.
Once the internal memory is used up by images, the user has to download and erase the images to continue taking pictures.

Removable

Removable memory is like a roll of film for conventional cameras that can be re-used over and over again.
Currently there are four different methods in use:

·         PC cards

·         SSFDC (Solid State Floppy Disk Card)

·         Miniature card

·         Compact Flash

·         Floppy Disk

Usability

Viewfinder

A viewing device on a digital camera to show the subject area that will result in the image stored.

LCD Display

With a LCD (Liquid Crystal Display) a subject or image is viewed through a small screen, ranging between 1.8 and 2.5 inches in diameter. The LCD enables the user of a digital camera to instantly view the taken image and reshoot if not satisfied.
One small disadvantage however is that the screen is hard to read in bright sunlight.

Flash

A brief, intense burst of light from an electronic flash, usually used where the lighting on the scene is inadequate for picture-taking.
If available the range is listed within the flash is effective.

Flash Modes

List of the various modes the flash can work:
Auto: Automatic flash activation in low light and back light situations.
Red-eye Reduction: Flashes several times before taking the picture and thereby avoiding the red-eye effect.
Off: No flash activation at all.
On: Forced activation.

Self-Timer

With a built-in self-timer, you can take pictures and be in it too.

Interface

Describes the type of physical connection to transfer images to and from the digital camera to a computer, TV set or a printer.
Cameras can be connected through either the serial or the parallel port.

General

Power Supply

Lists the number and type of battery to power the digital camera. Most manufacturers offer optional AC adapters.

Dimensions

Physical characteristic of the digital camera.

Weight

Physical characteristic of the digital camera.

Software

Nearly every digital camera ships with imaging software for enhancing and retouching photos, as well as camera driver software.

Extras

Mentioning of features that are unique to the digital camera.