The focal length of the lens you use can make a huge difference to the overall look of your image and the above GIF, that shows several shots of the same chap, demonstrates this perfectly.

The GIF quickly cycles through 11 different focal lengths to show how each one changes the shape of the subject's face. Starting at 20mm and finishing at 200mm, the subject goes from having a squashed face and enlarged nose to something much more balanced somewhere in between the two extremities.

This particular demonstration only looks at head shots so if you're photographing three-quarter length shots or even full-length images, what focal length produces the best results will be a little different. We actually cover focal length suggestions for portraits in our practical guide that covers shooting head & shoulder shots, three-quarter length portraits and full-length images. Wide-angle lenses can also be used creatively to capture portraits but they tend to produce better results with full-length images rather than straight on, head and shoulder shots.

To really get your fill of portrait photography lessons, take a look at our round-up of 29 top portrait photography tutorials. We also have a rather cool round-up of 68 portraits that have won our Editor's Choice accolade that is well worth checking out.