Zoom range is an important selling point, especially for compact cameras, where the average buyer may have difficulty working out the lens's range from its focal lengths alone.
Superzoom cameras like the Canon PowerShot SX30 IS have the largest zoom range of all. This camera has a 30x optical zoom, and the diagram below shows the huge difference in scale between the wideangle end of the zoom range (the tiny figure on the left) and telephoto end (the large figure on the right).
It can be misleading, though, if you start to assume that the bigger the number the better the lens. One problem is that the zoom range doesn't tell you the lens's widest angle of view, which is very important. Being able to magnify distant subjects is all very well, but in everyday photography a wideangle lens is more useful for 'getting everything in'.
It is important, then, to check the focal lengths anyway. A 5x zoom with a focal range of 24-100mm equivalent is likely to prove a lot more useful in everyday use than a 10x zoom with a focal range of 35-350mm, because a lot of the time the 35mm minimum focal length just won't prove 'wide' enough.
The other problem is that zooms with a very long range don't always perform that well, particularly at their maximum zoom, where pictures can often come out quite soft-looking and low in contrast. This can happen even if the camera uses a very high shutter speed, demonstrating that it's the lens that's the problem, not camera shake or user error.
The performance of superzoom cameras can often be quite disappointing for this reason, and this applies to pretty well all lenses with an extra-long zoom range. They're more versatile than normal lenses, but the quality is usually compromised to some degree.
