Batteries and Power Sources | Editing Software | Exposure Controls
File Formats | Flash Features | Focus | Lens
Price | Resolution | Shooting Modes | Storage Capability
Downloading Images to your Computer | Viewfinder and LCD Monitor | Downloading Images to your Computer

Low End	May use alkaline batteries; and use them, and use them! May also use AA lithium batteries, which last longer than the alkaline variety.
Midrange	Look for rechargeable NiCad or NiMH batteries and for an AC adapter, which will allow you to use a power cord when not out taking pictures.
High End	Uses rechargeable Lithium Ion battery and AC adapter. May also include a car battery adapter to be used with a special cable kit.

Software editing programs run the gamut much like the digital cameras do. Simple programs allow you to crop and adjust the brightness and contrast in your photos. Higher end products, such as Adobe Photoshop, allow you to adjust color levels, sharpen images and parts of images, and save pictures in many different file formats.

In digital photography, exposure is the amount of light that hits the image sensor when you snap your photo. If too much lights hits the sensor, your photo will be over- exposed; if too little light hits the sensor, your photo will be under-exposed.

Image Sensor	The image sensor in a digital camera is analogous to the film in a conventional camera. A digital camera has no film. Instead, there is an array of sensors that are simply light sensitive computer chips. When light hits these sensors they emit an electrical charge that is converted into digital information by the camera’s processor.
Shutter Speed	The shutter is placed between the lens and the image sensor. The longer the shutter stays open, the more light hits the image sensor.
Aperture	The aperture is an adjustable piece of equipment between the lens and the shutter. The larger the aperture, the more light can strike the sensor or film.

File Format describes the particular computer code used to store your files. There are many different image file formats. The most common, however, are JPEG, TIFF, BMP and GIF. When attaching a picture file to an email, the two file formats that are used most frequently are JPEG and GIF. For example, you might receive a picture file attached to an email that looks like this …puppy.jpeg. Because the file format is JPEG, you will immediately know it is an image.

JPEG	Joint Photographic Experts Group… The most widely uses file format for pictures, JPEGs are platform independent. They can be opened easily on both Mac and Windows. A JPEG image is one that has been compressed.
TIFF	Tagged Image File Format … TIFF files are platform independent and can be opened by both Mac and Windows. Because TIFF images are not compressed they tend to be large and require lots of storage space on your hard drive. Pictures in TIFF format are a basic file format for the printing industry.
BMP	Bitmap … BMP files are not compressed. The files are large and used primarily for Windows wallpaper images.
GIF	Graphics Interchange Format … GIF files are platform independent and can be opened on both Mac and Windows. This early picture format uses only 256 colors and has been surpassed by other choices. GIF files, however, are still one of the easiest file formats to attach and open on email.

There are several different flash options that are available for digital cameras.

Auto Flash	The camera decides if the flash fires, depending on the amount of light in the shot.
Fill Flash	The camera will fire the flash in any lighting condition, even bright sun. This is useful in a shot with uneven lighting or shadows. (Also called Flash On).
Red-eye Reduction	The flash fires a "mini" flash of light to fool the iris of the subject’s eyes into closing a bit before the real flash fires and the picture is taken.
Slow-Sync Flash	The flash fire time is extended to better illuminate the darker or background areas of your shot.
External Flash	Many high-end cameras enable the user to attach an external flash unit to the camera
No Flash	No Flash is an option for those times when the camera thinks you want a flash, but you don’t.

Focus is the word used to describe the quality of a photo’s detail. For example, when the subject of the photo is in sharp detail, the camera is in focus.

Focus-free or fixed-focus	Found on low-end cameras, a fixed-focus system is not adjustable. Fixed-focus is designed to give best results when the subject is at least four feet away from the camera.
Autofocusing	Autofocusing (AF) cameras can electronically estimate the distance to the main subject. This is usually done with an infrared light that bounces off the subject
Manual-focusing	Manual-focusing enables the user to determine focusing distances. This is usually an option on higher-end cameras.

The lens is the camera’s eye. The lens collects the light reflected off the photo subject and directs it to the camera’s image sensors. There are many kinds of lenses, such as telephoto and wide angle lenses.

High-end cameras offer the user the option to attach external lenses to the camera body. Middle range cameras generally have built in zoom capabilities, but do not offer the option to attach external lenses to the camera body. There are two types of zoom capabilities found on middle range cameras.

Digital Zoom	The camera uses software manipulation rather than a true optical lens to zoom in on a subject. The software program discards pixels on the edge of the picture and enlarges the center subject area.
Optical Zoom	An optical zoom brings the subject closer before recording the image. An optical zoom gives better results than a digital zoom.

Low End	$150 and under
Midrange	$150-$500
High End	$500 and up

Simply put, resolution is how you define the sharpness of your digital image. Resolution is often defined as how many pixels per inch (ppi) your image has in both its height and width.

Low End	pixels at 640 X 480
Midrange	pixels at 1600 X 1200
High End	pixels at 2048 X 1536 or higher

Some low-end cameras, most middle range and all high-end cameras give the user options on how they wish to set up their photos. These options are called shooting modes. Some of the most common shooting modes include the following.

Macro	Macro mode is used to shoot subjects at very close range, from inches to a couple of feet away from the camera.
Portrait	Portrait mode is used when you want a particular subject to be sharp and clear, and the background to fade into the background.
Landscape	Landscape mode is used for panoramic, scenic views and distant objects.
Continuous	Continuous mode enables the user to take successive shots by holding down the shutter button.
Black and White	Black and white eliminates color in the photo and is used primarily for artistic shots.
Stitch	Stitch mode enables the user to shoot images that overlap. Later these images can be merged into a panoramic photo using software on a computer.
Self-Timer	Self-timer enables the user to set the camera to automatically take the picture several seconds later. This mode allows the picture taker to also be in the picture.

Storage capability refers to how and where the camera saves images.

On-board memory

Many low-end cameras save the image on their "hard drive" or on-board memory. Once the memory capacity is reached, the user will have to download from the camera to the computer and clear the on-board memory before any more photos can be taken.

Removable memory options

There are several different types and technologies for removable memory. These range from simple floppies, mini CD-ROMs to small stamp-like cards that can be inserted into the camera. All provide the convenience of enabling the user to simply replace the card when it is filled without having to immediately download images to the computer. Removable memory cards are more expensive than film, but are reusable.

Removable memory gives the photographer many of the same advantages as film. When the card or floppy is filled, the photographer can remove the card or floppy and insert a new one into the camera. Here are some examples of memory storage options used by different types of cameras.

	Floppies are easy to use, but have limited memory capacity.
	CD-ROMs in digital cameras have adequate memory, but require a larger camera to accommodate the disk’s size. Some digital cameras use mini-CDs.
	The CompactFlash and SmartMedia cards are about the size of postage stamps. These cards can be purchased with different memory capacities.
	A Memory Stick look like a stick of gum. A proprietary product of Sony, the Memory Stick can be purchased with different memory capacities.

There are a number of different ways to transfer images from a digital camera to a computer. By far the most common method is to use a cable connection from the camera to the computer's USB port.

Cable	Most digital cameras come with a USB cable. When ready to download pictures, the cable is connected from the camera to the computer’s USB port. Software on the computer recognizes the camera and opens the image file.
PCMCIA slot	A PCMIA slot is found on most laptop computers. A device known as a Picture Card Adaptor fits into this slot. A Compact Flash card can be inserted into this device and the images transferred from the card to the computer.
Infrared	Some high-end cameras offer an infrared method of transferring images from the camera to the computer.

Digital cameras use two different methods for composing a picture image.

View Finder	Low-end cameras rely on the traditional method of looking through a window to line up a picture subject.
LCD Display	Middle range and high-end cameras have a LCD (liquid crystal display) monitor for viewing pictures. Although very helpful in composing and viewing pictures, the LCD feature is a drain on batteries.