Hardware Reference
In-Depth Information
the total number of pixels. Table 3.2 provides some examples. Some of the highest-quality
digital cameras today exceed 24 megapixels in resolution.
TABLE 3.2
Megapixel to resolution comparison
Megapixels
Image Resolution
×
4
2272
1712
×
6
3072
2000
×
8
3264
2468
×
10
3872
2592
Camera Size
Some cameras are much more lightweight and portable than others.
Zoom
There are two types. An
optical zoom
camera uses a real multifocal length lens,
and it's preferred. A
digital zoom
camera doesn't use a zoom lens; it simulates zooming by
interpolating the picture. Digital zoom isn't as good because it's guessing at some of the
pixels, rather than actually capturing them.
Storage Medium
Most digital cameras store pictures on fl ash memory cards like the ones
you learned about in Chapter 2, “Input and Storage Devices.” They vary in the types they
support (CompactFlash, Secure Digital, memory stick, and so on).
PC Interface
Different cameras have different means of connecting to a computer. Most use
either a USB or FireWire connection. (Not all PCs have a FireWire port, so a USB-interface
camera is a safer bet for wide compatibility with the different computers you may use.)
Manual Adjustments
Most digital cameras are fully automatic, but experienced 35 mm
camera users may want a model that has more manual options available such as aperture,
exposure compensation, focus, and shutter speed.
Delay Between Pictures
Higher-end cameras can take multiple shots very quickly, with
limited recovery time between pictures.
Video Capture
Some video cameras, although primarily used for still images, can also
record short motion video clips, with or without sound.
Webcams
A web camera, or
webcam
, is a low-resolution video camera that feeds its images directly
into a computer or network, most often using a USB or network connection. A webcam can
also double as a digital camera, although you can't use it while it's disconnected from the
computer. Many people use webcams for online video chatting and conferencing.
