Glossary Term: Digital Zoom
One of many advantages IP cameras have over analogue CCTV is the capability to go beyond optical zoom.
An analog camera may have optical zoom capability, but there’s no scope to go beyond this fixed, mechanical zoom level. Digital zoom provides a solution to this, allowing, in some of the most sophisticated examples, true clarity at massively high zoom. Take, for instance, the Panasonic i-Pro WV-NW964, which has a 30x optical zoom capability. Combine this with its 10x digital zoom function and the camera offers exceptional image quality up to a massive 300x zoom.
Now, even the best digital zoom suffers from a reduction in quality, but in the best examples the perception of clarity and focus remains high.
It works like this: as soon as optical zoom is exceeded the camera begins to digitally extrapolate a zoomed image from the source image at highest optical quality. This work is all done in the processor of the camera and therefore digital zoom should not be confused with optical zoom, but simply seen as an extention of optical to give a higher zoom range, with a progressive loss of quality.
[...] There are many IP cameras available today which have a zoom lens and this allows the camera to enlarge areas of a scene so that more detail can be seen from distant objects. This is not to be confused with digital zoom, which is another feature entirely. [...]