a540

Hi, Just wanted to know as above. My new powershot A540 has 3X digital/4X optical zoom. My friend's S3IS has 10X optical zoom. What do these terms mean?

Hello, I am interested in buying a digital camera in the range of 15,000 to 20,000 RS. I have basically narrowed it down to two choices after reading a lot of reviews by users and professional reviewers. Both of the cameras I have chosen are Canon's, they are in order of preference the...