Shooting Digital Photos with an Optical Zoom
Your digital camera may have an optical zoom, which is an actual, old-fashioned zoom lens (as opposed to a digital zoom). To use your digital camera’s optical zoom for close shots, take these picture-preparation steps before triggering that zoom button or switch:
Take the potential for a parallax error into account.
The closer you get to your subject, the greater the chance of a parallax error because your viewfinder and lens see things from slightly different angles.
Decide how much background you want.
When you zoom in on a subject, you can fit less of the background into the frame than if you zoom out and get your close-up shot by moving nearer to the subject, as illustrated in this figure.
Choose a depth of field.
Zooming in tends to make the background blurrier than if you shoot close to the subject because the depth of field changes when you zoom. With a short depth of field — which is what you get when you’re zoomed in — elements that are close to the camera are sharply focused, but distant background elements aren’t.