What is the effect of using a zoom lens on an image?

Using a zoom lens affects the composition of an image significantly in the way it magnifies the subject. Unlike fixed focal length lenses, zoom lenses allow you to adjust the focal length, which enables you to either bring distant subjects closer or capture broader scenes without changing your position. By zooming in, you create a larger image size on the sensor, adding detail and presence to the subject being captured.

Zoom lenses are versatile tools, facilitating not only magnification but also the ability to frame a shot precisely according to the desired composition. While they can also influence depth of field and other factors, their primary effect is indeed the ability to adjust the image scale, making the subject appear larger within the frame.