Before Buying the camera and selecting between optical or digital zoom we need to first know the different between digital & optical zoom then we can decide which one works best for us.
Digital zoom is not actually the zoom we generally understand as it only enlarges or expands a portion of an image we are focusing. It is similar to editing an image by cropping it in an image editor & then enlarging it, result will always be a low quality image. It means that greater the zoom we will use lower the picture quality will be.
Optical zoom works better in a way that it uses the optics (lens) of the camera to bring the subject closer thus not effecting the image quality.
So the optical zoom is always recommended whenever there is a choice as it will actually zoom in your picture without bringing down the image quality.
Now what if we do not want to spend more money and our choice of camera does not have an optical zoom option in it then digital zoom can also be used however we must have an idea that more zoom in will be hurting the image quality more.
The picture quality after using digital zoom also depends upon the number of pixels used in an image e.g. If 1x zoom is used with 2Megapixels camera then we can have good image on 4×6 print however with same 2Mega pixel if 2x zoom is used then it may blur the picture little resulting in a bit low quality image. On the other hand if we are using a 4megapixles camera (More detailed image, same image in 4 million pixels) then we can zoom in the picture more still can have good quality image, However we need to be careful as if 4x zoom is used & we want to have a lager print of say 8×10 that will not result in a quality image.
We will always suggest to use Optical zoom however it does not mean that digital zoom is worthless as we can also have digital zoom in our digital camera and can still have good quality images by wisely using it.