Every portrait photographer who started with a kit zoom remembers the first time they swapped it out for a prime lens. The “Wow” factor of a bright, sharp prime is hard to match, even with the best zooms. Optical benefits aside, working from a fixed focal length encourages more natural photographer-sitter interactions and better spatial awareness. Read on to learn why so many portrait photographers love their prime lenses.
Excellent portraits have been made using just about every lens focal length, but for the purposes of this article, a “portrait prime” refers to lenses that fall somewhere between 50mm and 135mm. Once you start getting wider than 50mm or closer than 135mm, you start to run the risk of distorting your sitter in ways usually considered unflattering. If your work is geared toward groups and environmental portraits, stick to the wide end of the portrait spectrum. It is hard to go wrong with the famously versatile 50mm lens as a first prime lens. If you plan on focusing primarily on close portraits, 85mm, 105mm, and 135mm lenses are excellent choices for headshots, beauty, and fashion photography. One quick note: These are 35mm equivalent focal lengths, so if you are shooting with a camera that has an APS-C, Micro Four Thirds, or other format sensor, check the equivalent focal length before making your choice. Except where noted otherwise, the images in this article were taken using Sony’s FE 85mm f/1.8 Lens.
Among the practical reasons to use primes for portraits is that you can get faster, sharper lenses at more reasonable price points than you can with a zoom. As beneficial as having a range of focal lengths to work with is, even the best zooms are limited by physical factors that make them optically complicated and, consequently, heavy and expensive. Committing to a single focal length means your lens’s entire construction is designed to maximize sharpness and minimize distortion for its specific focal length. If you find yourself shooting from the same focal length on your zoom over and over, it is time to upgrade to a prime.
Optically, primes will match or outperform their equivalent focal length on zoom lenses. Compare the images above made with the Sony FE 85mm f/1.8 lens at f/3.5 (left) and the twice-as-expensive 70-200mm f/4 G OSS lens at f/4 (right). I had to double-check the EXIF data to confirm which photo was made with which lens when preparing this article. As mentioned earlier, prime lenses are faster than zooms so you can simply open up your aperture when confronted with a low-light environment. Remembering the lightweight factor, you can also safely shoot handheld at slower shutter speeds than is possible with many zooms, even with stabilization. The image below was possible because of how lightweight the FE 85mm f/1.8 is; it would have been extremely difficult to achieve this shot using a zoom or heavy prime since the camera was being held above the model. In instances like this, Eye-AF can be a tremendous help in locking focus when you can’t be behind the viewfinder yourself. Remember to always keep the firmware of your camera and lens up to date so you can take advantage of technologies like Eye-AF, subject recognition, and tracking modes.
Another feature that comes with the extended aperture range of primes is the ability to create images with selective focus. This is achieved by using the widest—or nearly widest—aperture setting of your lens to cut out the exact slice of focus that you want for your subject. Often used to emphasize the eyes of sitters in close portraits or accentuate subject-background separation, you can learn more about this technique here.
Less a material than a psychological attribute, working with prime lenses trains your eyes to see and frame the world according to focal lengths. Photograph people with the same prime lens long enough and it will carve out a niche in your visual cortex. Suddenly you will know exactly where you need to be relative to your sitter to get the exact shot that you have in mind. Composing shots becomes easier and more methodical. Need your shot to be tighter? Take a step forward. Wider? Take a step back. Your body’s movement replaces the need for a zoom lens.
Another consequence of removing focal length as a variable is that it encourages a more natural exchange with your sitters. Any photographer who makes portraits will tell you that the technical side of image making is only half of the game. Portraits are the products of the time and space you share with the person in front of your lens. The more present you can be with your sitter, the better your portraits will be. Using a prime lens means you don’t have to worry about accidentally nudging your focal length or deal with image stabilization or focus range switches. You can focus on your subject, literally and figuratively.
Do you make portraits? What is your favorite prime? Tell us why in the Comments section, below.