Some newer models have 18x zoom, but 10x is typical for most extended zoom digital cameras.
zoom is to enlarge the image and capture in a digital camera
There is no limit for the zoom of a camera, but the The 26X Longest Zoom Digital Camera is one of the longest zoom cameras on the market. But you can always buy a longer zoom for a camera that does not have one .
Optical zoom is way better than digital zoom as digital only expands the picture. Optical zoom actually zooms in.
Canon makes a high quality zoom digital camera. However, these cameras are very expensive. Go to a local electronics store and ask about a reasonably priced high quality zoom digital camera.
Optical and digital. With optical zoom, the camera uses lenses to magnify objects. In digital zoom, the camera's built-in software creates a magnified image.
The Panasonic LX7 digital camera has all the usual features found on a digital camera like digital zoom and face recognition but this camera allows for full manual control of the aperture ring expanding the zoom and focus of the camera.
YOur eyes
Depending on your camera, lenses are available or not available. Nikon, Canon, Olympus etc., all have very good zoom lenses for their cameras. You will also find good lenses from Tamron, Sigma, and Tokina, that would suite your requirement. However, I am assuming that you have an SLR camera...
The Panasonic Lumix DMC-FZ28 has the best zoom capabilities.
Depends what your using it for
I usually see anywhere from 6x to 12x optical zoom, then most digital cameras also have digital zoom, up to about 20x
The Canon S-series have great zoom and can even do digital zoom for distant objects.