Updated: Nov 14, 2018
As your skills advance in photography, you begin to understand the importance of using the correct focal length for certain situations. Focal length is expressed in millimeters (mm) and different lenses are capable of shooting at different focal lengths. A lens focal length can range from 4mm to over 400mm. The lower the mm the wider the shot. Some lenses are called primes which only shoot at one set focal length, while zoom lenses can adjust to many different lengths.
Simply put, if you are looking through a 24mm lens at a building you can see the entire structure as opposed to being zoomed in to 85mm and only being able to see the front door. When shooting events I like to start with some establishing shots. This situation will require a wider focal length. This gives the client a good shot of the venues set up. This image was shot around 18mm. It captures a lot of space and gives the viewer a good idea of where we are.
Another situation focal length is important is when taking portraits of people. For taking group shots, I tend to stick around 35mm. You will be zoomed in enough to show their faces in detail while wide enough to capture multiple people.
This is different from if you were to take a headshot or shoot portrait photography. The greater the focal length, the more out of focus (bokeh) the background will be. Most portrait photography will be taken between 85mm-200mm. This will bring most of the focus to the subject, while removing distracting background. This photograph below was taken at 200mm.
The more you shoot, the more focal length becomes another tool to capture exactly what you are looking for. Exploring different lenses is the best way master this area of photography. Let us know your favorite focal length to shoot at, and your thoughts on using different focal lengths.