^ the perspective has changed because the camera has moved away from the subject. In 18mm the camera is right next to the pink bottle, at 55mm it is quite a distance away. Zoom is utilized to keep the pink bottle at the same size, but the perspective change is due to the camera's movement, not the zoom.
From Wikipedia the caption for your photo is:
Quote:
How focal length affects perspective: 18mm (wide-angle), 34mm (normal), and 55mm (modest telephoto) at identical field size achieved by different camera-subject distances. Notice that the shorter the focal length and the wider the angle of view, perspective distortion and size differences change.
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If only a zoom was used, perspective would remain the same the image would just be magnified. Doesn't matter if digital zoom or telephoto.
Or if only the camera moved (but zoom not changed), perspective would change but the pink bottle would become smaller (because zoom is not counteracting moving away).
Here again from Wikipedia is an example of utilizing zoom but staying in the same position:
![](http://upload.wikimedia.org/wikipedia/commons/1/12/Angleofview_28mm_f4.jpg)
![](http://upload.wikimedia.org/wikipedia/commons/9/9c/Angleofview_50mm_f4.jpg)
![](http://upload.wikimedia.org/wikipedia/commons/6/68/Angleofview_70mm_f4.jpg)
![](http://upload.wikimedia.org/wikipedia/commons/f/fd/Angleofview_210mm_f4.jpg)
^Photos taken using a 35 mm still camera at a constant distance from the subject with a 28 mm lens, a 50 mm lens, a 70 mm lens, and a 210mm lens.
Changing lens, telephoto, optical zoom, digital magnification, none of that changes perspective. Perspective only changes by moving the camera. It's just to get the so-called telephoto perspective, you need to move the camera so far away that the subject would be tiny if not for a telephoto zoom to magnify.
Image credit Wikipedia user Koyaanis Qatsi.
Source for Wikipedia stuff
http://en.wikipedia.org/wiki/Perspec..._(photography)