Although most lenses can be used for portraiture, fast telephoto lenses with moderately short focal lengths have long been the first choice of professional portrait photographers. Focal lengths typically considered ideal range from about 70mm to 135mm in 35mm format, with a bias in favour of the 85-105mm section.
There are several reasons to choose short telephoto lenses for portraiture:
1. They provide a good working distance, enabling the photographer to fill the frame with the subject’s face (or head and shoulders) without imposing on their personal space.
2. The slight compression of perspective provided by a telephoto lens is usually flattering. With careful posing of subjects, prominent noses and chins appear smaller in relationship to the rest of the face.
3. Fast maximum apertures (f/1.8 to f/4) provide optimal depth of field control, making it easier to draw attention to key features like the subject’s eyes or profile, while allowing the rest of the scene to drift gradually out of focus.
Wide aperture settings (f/2.8 in this case) with a short telephoto lens provide the classic recording tools for head-and-shoulder portraits. (Source: Tamron.)
However, that doesn’t mean other lenses can’t be used for portraiture; just that they need to be used more thoughtfully. Longer lenses will generally be preferred for candid portraits, while wide angle lenses can produce attractive environmental portraits, particularly when the shots show people at work or engaged in an activity that doesn’t require them to look straight at the camera.
Backgrounds can make or break portrait shots. Longer focal length lenses will make blurring away a distracting background easier, as will wide aperture settings. Longer lenses also make it easier to fill the frame with the subject’s face, creating a sense of intimacy. It’s important to achieve an optimal balance between depth of field and background blur, bearing in mind that the subject’s eyes and mouth should always be in focus.
A portrait taken with an 85mm lens on a camera with an APS-C sized sensor, which provided the equivalent to a 135mm lens in 35mm format. This allowed a good working distance for photographing this type of subject.
A 250mm equivalent focal length and f/5 maximum aperture have been used to isolate the subject from a potentially distracting background. The camera was focused on the subject’s eyes.
Zoom or Prime?
Prime (single focal length) lenses are usually preferred by photographers who are serious about portraiture. As well as offering superior image quality, their main advantage over zoom lenses is their significantly greater speed (light transmission).
All leading manufacturers offer 85mm lenses for the 35mm format with maximum apertures of f/1.4 and f/1.8, which is considerably (two to 2â…” f-stops) faster than the typical f/3.5 maximum aperture for a short telephoto zoom lens. Fast lenses require less stabilisation in low light levels and can be used with lower ISO settings. In addition, the faster the lens, the greater the potential for it to produce attractive background blurring (‘bokeh) that makes potentially distracting objects behind the subject less noticeable.
However, prime lenses tend to be relatively large, bulky and expensive and when the focal length isn’t ideal for the subject you must change to a different lens. This takes time and can create potential for dust to enter the camera. Both these problems are solved with a zoom lens.
Zoom lenses are much more versatile than primes ““ and usually more affordable, although their prices are dictated by optical speed and build quality. One zoom lens will take up less space and weigh less than several prime lenses that cover the same range of focal lengths.
A ‘convenience’ zoom lens made it easy to compose and take this candid portrait shot without attracting the subject’s attention. Photographed with a focal length of 185mm on an APS-C DSLR camera using a relatively wide f/6.3 aperture to produce background blurring.
Focal Length Analysis
In this section we will look at some popular focal lengths for portrait photography and analyse their characteristics to suggest situations where they can be used effectively.
85-105mm: Physically, lenses in this range tend to be compact and light enough for easy hand-held shooting. They’re also well suited to flash photography, particularly with low-output flashguns.
Shorter telephoto lenses provide a wide enough working distance for the photographer to change position quickly without the need to move tripods and lights. They also enable photographers to get close enough to fill the frame without intruding on the subject.
105-135mm: Because they provide a greater working distance, lenses in this range can be used for candid portraits but are also suitable for posed portraits. Physically they are usually larger than the short telephotos but not so large as to require tripod mounting in adequate light levels. The additional compression of perspective they provide can be used to advantage with many subjects, as can the ability to control background blurring by moving the subject further from a distracting background.
Longer than 135mm: Medium-to-long telephoto lenses are favoured by action and sports photographers as well as photographers who enjoy taking candid shots. The longer the focal length, the greater the potential for a shallow depth of field, which can isolate subjects from the background and create strong, pleasing portraits.
Shooting from a long distance with a high-magnification lens will make the background ““ and any objects in the foreground ““ appear much closer to the subject, giving a far more enclosed effect. It’s easier for head-and-shoulders portraits than full body shots. You’ll need plenty of space to fit the whole figure in the frame.
Longer focal lengths ““ in this case, 200mm ““ are often used by wedding photographers because they make it easier to isolate subjects from the background. (Source: Tamron)
Wide Angle Lenses for Portrait Photography
Wide angle lenses force you to be much closer than you would with a standard portrait lens and this requires more interaction with the subjects. While they might not work for head shots, they work well for environmental portraits that show one or more subjects in their natural context. It’s important to keep the wide-angle lens square to your subject(s) to minimise distortion.
Aside from being able to include more of a scene in the frame, wide-angle lenses are usually quicker to focus, which will enable faster shooting and make it easier to capture fleeting expressions. It’s also easier to focus on subjects both close to and distant from the camera. They can also be used to capture the space around the subject(s) and include items that connect the subject to the background.
Wide angle lenses are often used for group portraits, rather than shots of individuals. However, because they tend to make objects close to the lens appear relatively large with respect to the background, they can distort parts of the subject. For example, in a portrait of a person’s face taken with a wide angle lens up close, the nose will look huge because it is closer to the lens than the rest of the face.
Some types of portraits can use wide angle distortion creatively. It’s quite common to see portraits of comedians and other entertainers taken with wide angle lenses, using the distortion to accentuate the comedic effect.
As long as you keep the wide-angle lens square to your subjects to minimise distortion, the different perspective lends itself especially well to photographing groups of people in their surroundings, particularly at gatherings like weddings and parties.
Interestingly, portraits taken with a wide angle lens from slightly below the subject’s waistline can make them look taller. However, if the camera is too low, the subject’s feet and legs will appear larger and longer and out of proportion to their head.
With the camera above the subject’s head, the opposite effect is achieved; the subject’s head is large and their body converges down to a point at their feet. This makes them look rather childlike. You can also use the distortion created by the lens to exaggerate foreground objects or to create an interesting frame for the subject.
A 300mm focal length on a 35mm format camera makes it easy to isolate the subjects from the background and produces strong background blurring. (Source: Tamron.)
An 18mm wide-angle lens on a camera with an APS-C sensor enables everything in the scene to be sharply focused, providing a context for the subject. An environmental portrait taken with a wide angle lens. In this case, a 17mm lens on a DSLR with an APS-C sized sensor, which covers an angle of view equivalent to 25.5mm on a 35mm camera. (Source: Tamron.)
Excerpt from Lenses Guide.