Films of different frame sizes and different sensitivities to light.
A light-sensitive silicon chip determines the frame size and the light sensitivity of the camera. Pictures are recorded on reusable memory.
Picture framing
An optical viewfinder is used.
An optical viewfinder and/or LCD display are used.
Picture storage
Images are stored as digital files on reusable memory.
Images are stored directly on the film, which is single-use and has a fixed number of frames per roll.
Picture Display
Displays pictures on the LCD or can also be viewed on a PC.
Barring a few advanced models, the pictures cannot be displayed before developing the negatives.
Photo printing
The image files can be downloaded to the computer for printing on home printer or if the printer is compatible, the camera can be directly connected to the printer.
A professional photographer's services are required for developing negatives and getting prints.
Power
Disposable and rechargeable batteries.
Usually disposable batteries.
Digital Camera Features:
Size
The digital cameras come in undernoted five sizes:
Ultra-Compact: Fit in pockets and is easy to carry. Usually have fixed focal length or folded optical lenses.
Compact: Easy to transport, can be carried in a pouch. Have retractable zoom lenses.
Medium: Need a camera bag to carry. Usually have fixed zoom lenses.
Large: Need a large camera bag. Have fixed zoom lenses. Offer more controls.
SLR: Large size. Have interchangeable lenses. Provide the most flexibility to shoot variety of scenes and deliver best quality optics. Used by professional photographers.
Resolution
A digital picture is made up tiny dots, called pixels. A megapixel corresponds to roughly one million pixels and is used to describe the density of pixels in the image captured by the camera. The
higher megapixels in a camera enable it to capture more details in the picture.
The number of megapixels required is related to the size of the print out/display you want to have. For a print out of upto 8" x 10" a 6-7 megapixel camera gives good results. If you want to have
larger printouts than higher megapixels are required.
Optical Zoom
Optical zoom is the ability of a camera to capture a smaller area from a given location of the camera. The greater the optical zoom, the smaller the area that can be photographed. It is equivalent to
going closer to the subject. Optical zoom is measured by how much closer the camera can get compared to its position from the subject. A 3X optical zoom can make a subject appear three times closer.
Digital Zoom
Digital Zoom magnifies the picture of the zoomed object without adding on the details in the picture resulting in loss of quality.
LCD (Liquid Crystal Display)
LCDs refers to the small screen on the back of a digital camera and are described by their size (usually of 2"-2.5") and by their resolution. LCDs are used for viewing the pictures taken and to
preview the picture to be taken. LCDs usually loose their brightness in daylight/sunlight. TFT coated LCDs are brighter and better as the brightness loss is lesser.
Flash
A flash on a camera is a small lamp to illuminate objects to be photographed. A pop-up flash is normally hidden and pops-up when used.
Viewfinder
Viewfinder is used to look at the object to be photographed and position it in the frame. While an LCD can be used as a viewfinder in most digital cameras, the majority of digital cameras also have a
viewfinder.
Face recognition technology
This helps in finding the person in the frame and to apply its auto-focus to that area in order to make sure that the face is in focus.
Video and Audio Recording
Most digital cameras can capture video clips. The quality usually available from a digital still camera is 30fps with 640x480 resolution and sound. Some cameras allow to record a continuous clip
without time restriction while others put a time limit of 30 seconds or so at a time. Further all cameras that shoot video do not capture sound. This aspect should be checked at the time of buying
the camera.
Some cameras also work as audio recorders, allowing to record hours of audio subject to availability of memory. A built-in speaker in addition to the microphone will enable to play voice
recordings back on the camera.
Video-conferencing
Some cameras can be used as Webcams and come with the requisite video-conferencing software. To use this feature, a camera with a built-in microphone is preferable so an external microphone is not
required for video-conference with sound.
Batteries
The digital cameras usually come with two types of batteries:
1. Lithium-ion or Nickel Metal Hydride (NiMH)
Advantages:
Long life
Compact and lighter
Less expensive in the long run
Disadvantages:
Require electricity to recharge
Need to keep charged extras on hand
Don't always have other alternatives
2. Disposable or rechargeable AA sized
Advantages:
Readily available in stores.
Inexpensive to replace.
Disadvantages:
Usually two AA-size batteries are required, which adds to weight and size of camera.
