The ability of the camera's CCD to capture a full range of shadows and highlights.
Digital Zoom
Unlike an optical zoom, the digital zoom takes the central portion of the high-resolution sensor's image to achieve the effect of a zoom. This means that the existing data is not enhanced or added to, merely displayed at a lower resolution, thereby giving an illusion of an enlarged image. All PowerShot cameras utilize the superior optical zoom, which actually augments the data collected by the sensor, rather than merely creating the illusion that the image has been enlarged.
Digital Print Order Format (DPOF)
Digital Print Order Format (DPOF) is a standard format control file that is stored in the digital still camera's removable memory card, which specifies which image files should be printed, and the number of copies.
Diaphragm
The adjustable aperture of the lens. It restricts the amount of light allowed into the camera. This term can also be applied to shutter types, i.e. iris diaphragm shutter, which is a set of interposing leaves, which open and close at a variable rate to produce a between-the-lens shutter.
Developer
A chemical solution that changes invisible images exposed on light-sensitive film or paper into a visible image. Utilized in traditional camera film processing.
Depth-of-field
The zone of in-focus elements, from front to back. Another way to put this is the range of distance that is acceptably sharp within a photograph. Depth-of field varies inversely with the aperture opening. In other words, a wide-open lens with an aperture of f/1.8 has little depth of field; if stopped down to f/16, almost everything from front to back will be sharply in focus.
Dark Current
a.k.a. noise, dark noise. Pixels collect signal-charges in the absence of light over time, which can vary from pixel to pixel, and the result is known as dark current. PowerShot digital cameras reduce or eliminate dark current before a picture is captured.
