
Using fast prime lenses to create razor-sharp portraits where the focus melts away like butter can be an addictive (and costly) pastime. The jump from an 85mm f/1.8 to an 85mm f/1.4 may seem minor on paper, but anyone who has used both lenses knows that the difference extends well beyond a few decimal points. This article is an homage to the top-tier primes designed for the most demanding portrait photographers. Hide your wallet before proceeding.
Photographs © Cory Rice
For the purposes of this article, “portrait” prime denotes a lens with a focal length that falls somewhere between 50mm and 135mm. Sure, you can make a great portrait wider than 50mm or closer than 135mm, but the consensus holds the above range ideal for rendering faces and bodies in a “naturalistic” manner. Likewise, “fast” means f/0.95 to f/1.8, depending on the focal length of the lens. Of course, you can make excellent portraits with slower lenses, but that discussion is for another article. The images in this article were taken with either a Sony FE 85mm f/1.4 GM or 135mm f/1.8 GM lens.
Just as the upgrade from zoom to prime is immediately visible, so too is the effect when you move from a low- to high-end prime. These are lenses with significant optical and interface upgrades compared to their smaller siblings. The elements are larger, designs more complex, and coatings more advanced. This leads to less distortion, sharper rendering, and smooth focus falloff. It also results in heavier lenses that are generally less suited for everyday carry but excellent in the studio.
Somewhat ironically, many photographers are lured to fast primes as much for the quality of their bokeh (out-of-focus rendering) as for their sharpness. No high-end prime is designed or marketed today without a tremendous amount of attention paid to the quality of bokeh it produces. This is due in large part to the popular, if somewhat controversial, school of “wide open” portraiture, which takes advantage of the maximum aperture of fast lenses to isolate subjects from their environments. If your aim is to work with extremely shallow depth of field, the faster your lens, the better. On the other hand, it is worth pointing out that typically the best corner-to-corner sharpness or “sweet spot” of a lens is 2.5-3 stops down from its maximum aperture. For a more in-depth discussion of shooting wide open or stopping down, check out this article.
Another reason to use a fast prime is to extend your ability to shoot in low-light situations. This serves as a practical instance where an extra stop or two can mean the difference between what is and is not possible to capture without noise or camera shake. Remember, these are often heavy lenses so you will need to be mindful of what shutter speed you are using when shooting handheld to avoid compromising image quality.
In addition to optical upgrades, prime lenses at the highest level tend to have more advanced physical designs. These are lenses made for professionals and are designed to survive the abuses of set life. Durable constructions, weather resistance, and protective coatings are par for the course here. Beyond physical construction, many incorporate on-lens controls to simplify professional workflows. Customizable buttons cut back on time spent navigating menus or buttons on your camera. Switches for changing between manual and auto focusing modes allow you to refine focus quickly, a major advantage when making portraits with shallow depth of field. While not necessarily a portrait-specific feature, many advanced primes incorporate de-clickable aperture rings for creating smooth video footage. Finally, some even incorporate their own digital displays or customizable control rings for managing settings. Many of these lenses now use updatable firmware for the best communication with your camera. It is always good practice to check for both camera and lens firmware updates when you get a new lens. This will ensure that any new features or bug fixes are taken care of from the start. For example, if you plan to shoot portraits with shallow depth of field, having the latest version of subject identification or Eye-AF can be the difference between a great shot and an almost-great shot.

For a rundown of the fastest lenses currently available by manufacturer, check out this article.
What is your favorite prime for creating portraits? Share your thoughts in the Comments section, below!