beginner question - how to use a viewfinder?

[Michael]

I recently bought a zoom camera. Its got a smallish rectangle shape at
the center of the viewfinder and the corner lines of a large rectangle
slightly in from the top left corner. I'm not sure how to position the
view when taking normal shots and zoom shots.

Any advice is much appreciated.

[Alfred]

If this is a compact autofocus camera then it is likely that the smallish
rectangle at the centre is the area of the picture that the camera uses to
focus. The large rectangle show you the framing of the actual picture.

[Francis]

The smaller rectangle is for the extended telephoto position of the lens, and
the larger one is for the wide angle position. In between, you have to estimate
what is in the image frame.

[Michael]

The smaller rectangle is for the extended telephoto position of the lens, and
the larger one is for the wide angle position. In between, you have to estimate
what is in the image frame.

Thanks - this was sort of what I was guessing but I was unable to
visualise it. Does anyone know any web-pages/ resources that explaing
the science/maths behind this?