In my previous article, I discussed my love for the 35mm focal length and why it would be my only lens if I couldn’t have another. In this month’s discussion, I’ll talk about why a long lens can be a useful addition to your arsenal. While it can be easy to dismiss longer focal lengths as being only necessary when things are far away, that really is selling them short. Let’s see why.
As we move into the realms of longer focal lengths, like 50mm, 90mm or 140mm, a few things begin to happen to our images. The optical effects of these lenses can be exploited to make interesting images not possible with shorter focal lengths, as Joe McNally will no doubt attest. While a 35mm lens can be used to render the world in a natural and comfortable way, a long lens such as a 200mm can be used to create a very different look. The longer the focal length, the more pronounced the effects below will become.
Bringing things close
The first (and most obvious) use for a long focal length is magnifying distant subjects. Objects farther away can essentially be ‘brought close’ or enlarged in the frame. It is for this reason that wildlife photographers and sports photographers make use of them. Instead of having to sneak up on a wild bird or dodge football players running at full tilt, the photographer is able to essentially bring the subject to them.
Professionals in those spaces can often be seen lugging around lenses that weigh as much as the whole kit of a family photographer. One only needs to look at Fujifilm’s 200mm f/2 to get an idea of whether or not they’re willing to work with a lens like that. High quality, fast aperture lenses with long focal lengths tend to get very large very quickly. However, there some slower aperture options that are much more portable, such as the brand new XF 70-300mm f/4-5.6.
One of the things that happens as we step away from a subject and let a long lens get us close is that the scene appears to get compressed. This is exactly the effect that Joe McNally was exploiting in the link above. This is called perspective distortion and results in elements in the frame appearing closer together on the depth axis. This is the result of the relative distance between the camera and the objects in the frame. As we move further away from things, they appear to be relatively closer to each other from our perspective.
This effect can be used in extreme cases, such as tourists pinching the Eiffel Tower or holding the sun. However, it can be used much more subtly by careful subject placement to create abstract patterns with the background or make a subject look much closer to other elements than they actually are.
Depth of field
Longer focal lengths produce a shallower depth of field for a given aperture and subject distance. So, if I take a portrait at 35mm and 90mm, both at f/2 and without moving back to accommodate the framing of the 90mm, the image produced by the 90mm lens will have a much shallower depth of field.
We can therefore use fast lenses with long focal lengths to effectively isolate our subjects with depth of field. A lens like the XF 90mm f/2 does an exceptional job of this. This is what typically makes a good ‘traditional’ portrait lens. A 56mm or 90mm lens affords the photographer a little space between them and their subject, meaning that their features will be flattened and flattered. It also offers shallow depth of field, giving the viewer a sharp portion of the image to rest their eyes on.
The narrow angle-of-view we get from longer focal lengths is also something we can make use of to minimise unwanted elements in our images. For example, consider making a portrait in a public park. There will likely be other people, signs or garbage cans that we don’t wish to be in the composition. Of course, we could frame them out but, sometimes, we cannot make that work with the desired angle. In these cases, the narrow field of view provided by a longer focal length can help to remove these elements.
This effect can also be useful in a studio portrait situation. For example, in a corporate client’s office, we could set up a 1 metre wide white backdrop. Using a 35mm lens would mean that we’d likely get some of the office walls or other elements in the side of the frame. Switching out for the XF 50-140mm f/2.8 and zooming to, for example, 70mm could shave the sides off the image and mean a whole lot less retouching.
A long focal length lens is a great addition to the bag for many types of photography. Unlike a ‘normal’ lens, the great benefit of a long lens lies in its ability to distort the way the human eye sees the world. We’re not used to seeing distant birds up close or backgrounds pulled close to people and blurred into unrecognisable patterns. This is where we can really make use of a longer focal length. Do you own a long lens? What’s your favourite use for it? Maybe you don’t own one, which one in the Fujifilm range do you covet most?