When you change the resolution setting, you are changing the digital zoom. Here take a look.
http://www.photoxels.com/article_zoom.html
My camera has 3x optical zoom, and 5x (? I forget the exact number) digital zoom; but only one button to activate zooming.
How can I tell which one is in use??
(I have a Sony CyberShot DSC-S30 - 1.3 megapixels. It may be old - but takes beautiful pictures!)

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