The question I hear most often from various friends and persons whom I instruct in photography goes a little like this – “I am thinking of getting lens – xyz; What do you think?” To be honest, I think the question should really be rephrased to – “I am thinking of doing this type of photography or taking these type of pictures; Do you think this lens is adequate?” It is true that you can take a photograph of the same scene with just about any lens but the qualities of different lenses allow you to interpret the scene differently. In the following text, I will attempt to explain how the lens is a shaper of image.
Telephoto lenses do two things particularly well – they isolate sections of a scene and they compress an image. By isolating a part of a scene, it is possible to make the subject of the image a lot more prominent and eliminate distractions. This is especially true if you are making use of a telephoto lens with zoom capability. With such a lens, it is possible to isolate your subject out of the environment and give you a more intimate photograph of your subject.
Further, by the very construction of the lens, telephoto lenses are more likely to create bokeh - a natural blurring of the background and or foreground due to the shallow depth of field. This allows the photographer to eliminate distractions by using the natural optical properties of the lens.
Wide Angle Lenses
Wide angle lenses allow for the spreading out of items in a scene giving the impression of more space between items. Lenses like these are frequently used by landscape photographers to show the grand scale of things. They have also been used in portraiture in unique ways. Arnold Newman used telephoto lenses to get as much into his photographs to explain more about the person whom he photographed.
The lens does not only change how much one can put within his/her frame but how he/she tells the story. And, dependant on the lens, chosen for the scene, a photographer may tell the story more effectively. I have posted a small video below to give a more visual explanation of how a lens can shape an image. Although, the photographer discusses more about telephoto lenses, I think he touches on some key points which explain the differences between using a wide angle V.S. a telephoto lens.