Different types of portraiture have slightly different equipment requirements.

Although portrait photos can be taken with pretty much any camera (including smartphones), interchangeable-lens cameras generally do the best job, since they let you select an appropriate lens, set the optimal exposure parameters and capture raw files to ensure you have the best starting point for processing your shots.

While it’s easy to take quick selfies with a smartphone, especially when you are on-the-go, a ‘proper’ interchangeable-lens camera provides superior results for most other portraits.

While portraitists working in studio environments are able to take advantage of large, high-resolution cameras, fast lenses and expensive lighting set-ups, the majority of photographers usually find their existing equipment can deliver satisfactory results. Their images may lack the polished, professional appearance of studio shots but they’re often much more engaging because they’re natural-looking and provide a more ‘truthful’ depiction of the subject.

It doesn’t really matter whether your camera is a DSLR or mirrorless model – or if it has a ‘full frame’, APS-C or Micro Four Thirds (M4/3) sized sensor. What matters most is your understanding of how to use it and whether you’ve selected the most appropriate lens and camera settings. These choices can, in fact, influence the end result more than you might initially think

Entry-level interchangeable-lens cameras often have easy-to-use presets that let users select adjustments for background blurring, brightness and contrast via touch controls.

Know your lenses

Most people know there are two types of lenses: prime (or single focus) and zoom. Prime lenses can usually be smaller, lighter and easier to make than zoom lenses but they’re generally less versatile. Zoom lenses provide versatility at the expense of lens speed and, often, size and weight.

Regardless of the type of lens, all lens designs are influenced by three factors: speed, weight and price. Designers must balance these factors to create lenses that consumers want and are prepared to buy and use. However, they are inevitably constrained by some important parameters.

Lens ‘speed’ defines how quickly light can reach the image sensor. It is determined by the size of the aperture that lets the light into the camera which, in turn, is dictated by the size of the glass ‘elements’ that make up the lens.

The fastest lenses which have maximum apertures between f/0.95 and f/1.2 contain large elements that require a lot of heavy glass. This makes them heavy to carry; some weigh two kilograms or more.

They also cost a lot to make, which means they’re even more expensive to buy. As a guide, every 1/3 of an f-stop of speed advantage you can expect at least a 200 gram increase in the weight of the lens and a $500 increase in its price.

Sometimes you don’t want to use a very wide aperture setting. While it can make it easy to blur out distracting backgrounds, the fastest lenses also have very shallow planes of focus, which can make precise focusing very tricky. There are also times when it’s better to stop down and reveal background details to add context to the picture.

Use of a wide lens aperture – in this case, f/2.8 – produced attractive background blurring for this close-up portrait.

Stopping down to f/8 for a different type of portrait added meaningful context to the shot.

Prime lenses for close-up portraits usually have maximum apertures between f/2.0 and f/2.8. This provides a shallow depth of focus with plenty of scope for creative background blurring. These lenses are often more affordably priced than the fastest lenses.

Zoom lenses are often a stop or two slower than primes, but they are easier to use and wide aperture settings usually produce attractive background blurring, especially at longer focal lengths so they shouldn’t be seen as inferior. The highest-quality zooms have constant maximum apertures, usually around f/4 for 24-105mm zooms.

Cheaper zoom lenses have variable apertures, such as a range from f/3.5 at 24mm to f/5.6 at 105mm. Both types of zoom lenses provide photographers with plenty of scope to be creative when framing shots than prime lenses. However, the ability to blur out backgrounds at longer focal lengths is better with constant maximum aperture zooms.

Lens choices

Fast telephoto lenses with moderately short focal lengths have long been the first choice of professional portrait photographers. There are two reasons behind the choice:

1. Moderate tele lenses provide a comfortable working distance between the camera and the subject, preventing the subject from feeling crowded out and overwhelmed by the presence of the photographer.

2. The short telephoto lens is considered by many professional photographers (and also equipment manufacturers) as ‘ideal’ for portraiture because of its flattering perspective. The most popular focal lengths lie between 85mm and 105mm in 35mm format, although this can extend to about 70mm at the shorter end or 135mm to 200mm in some situations.

3. Prime lenses are often used by studio portraitists, with fast 85mm lenses being popular for cameras that have 36 x 24 mm sensors. Fast zoom lenses are also popular with both professionals and photo enthusiasts because of their versatility.

4. Wide angle lenses are only suitable for photographing moderate-to-large groups of people. When used for individual portraits they often create unattractive distortions.

This combination of a high-resolution camera with a fast (f/2.8 constant maximum aperture) 24-70mm zoom lens allows you to take both individual and group portraits. It would be especially well suited to wedding and event photography.

5. Photographers shooting with cropped-sensor (APS-C or Micro Four Thirds) cameras need to take account of the effective focal lengths produced by the sensor’s crop factor. Most APS-C cameras have sensors measuring approximately 23.5 x 15.7 mm and a 1.5x crop factor, which means a 90mm lens covers the same angle of view as a 135mm lens on a ‘full frame’ camera.

Canon uses smaller sensors that measure 22.3 x 14.9 mm, which have a crop factor of 1.6x, so a 90mm lens is equivalent to a 144mm lens on a ‘full frame’ camera. M4/3 cameras use 17.3 x 13.0 mm sensors with a 2x crop factor so users of those cameras would find a 90mm lens has an equivalent focal length of 180mm.

Useful links

Lenses for portraiture

Choosing a lens kit

Excerpt from Portraiture pocket guideby Photo Review tech editor Margaret Brown.

Portraiture pocket guide Partner: