Most of the people when buying a digital camera would first look at its specifications or its description. Then they would probably notice the amount of zoom the digital camera provides which decides the quality of photographs. For instance the lens shown in the form of 3x or as 6x which is basically referred to zoom ratio. The ration provides you the most needed rule of thumb when using your digital camera zoom capabilities. However you should know that 3x digital camera zoom can provide different amount of zoom in other camera.
Calculating zoom ration or the number of times
All the digital cameras have focal length which is also true in cameras that don't have zoom lens. This focal length is basically the distance from the center of the optical lens to the focal point of the camera. In digital cameras this focal point is found on the sensor of the camera while in others it is found on the film. However those cameras that don't have zoom lens the focal length is fixed as the lens never change their position. When using zoom lens the position of the lens keeps on changing as your zoom out and in and the focal length decreases and increases respectively. The focal length in a digital camera zoom lens is often given in two figures and is always quoted in mm or millimeters.
Why zoom lens differ from digital cameras
It is actually very common to find two cameras that have the same zoom ration but one camera has better zoom than the other. Here the reason for it would be, one camera might offer a wider picture angle than the other, which means it has shorter focal length. There is a wide angle lens in cameras that offer wider picture angles. An advantage in having wider picture angle is that is lets you squeeze more in the picture for shots like group of people or landscapes, but it might not zoom in as much as you expect.
However for a long time now 3x has been the standard zoom ratio for a camera. Recently, there was also an instruction of significantly longer zoom lenses and currently the longest in 12x. However, if some exceptionally longer optical lens seems better option then you can even choose from a couple of useful considerations. However you should know that extended optical lens increases the probability of camera shake which can lead to blurred images. Additionally the images might also be a bit dark as less light tends to travel to the CCD where you will require better and longer flash and shutter speed.
It is not uncommon to find two zoom rations in a single camera which is optical and digital zoom. The digital zoom cameras are very different from optical zoom ones. In digital camera zoom there is special software inside the camera in order to zoom rather than a lens. This simply means that the software helps in enlarging parts of the image to provide the impression of zooming. There is an element of guesswork involved in the entire process which leads to some decrease in its quality. However you can still find cameras that offer both the optical and digital camera zoon features to be used together. For instance there are cameras designed by Canon called PowerShot and even by other manufacturers which can have 10x optical zoom with 4x digital camera zoom to provide you a combined 40x zoom.....see the complete article http://my-digital-camera.info/digital-camera-zoom