Why Upgrade to a Fast Prime Lens for Portraits?

Why Upgrade to a Fast Prime Lens for Portraits?

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.

Note the difference in size between the f/1.4 <em>(left)</em> and f/1.8 <em>(right)</em> lenses
Note the difference in size between the f/1.4 (left) and f/1.8 (right) lenses.

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.

Paired with the a7R IV, Sony’s FE 135mm f/1.8 is sharp enough to render the reflection of the studio in the eye of the model.

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.

To shoot wide open (left) or stop down (right)?

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.

Fast primes allow you to work with natural light more easily than slower lenses.

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.

Shooting for shallow depth of field can produce equally unique falloff for environments when captured at a distance.
Shooting for shallow depth of field can produce equally unique falloff for environments when captured at a distance.

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!



Great article! I love the images on white with the white outfit

Great article and lovely portraits! That orange lace collar complements the model and really shows off the defocused bokeh of the Sony FE135mm.

My favorite prime for portraits is the Pentax DA* 55mm f/1.4. This lens is APS-C only, so it provides an 85mm equivalent for portraiture. I use mine mostly for product photography to dissolve backgrounds. It's the sharpest lens I own, with a very flat field of focus that makes it awesome for photographing small groups. The SDM autofocus motor is utterly silent, but painfully slow. So it's great for headshots, posed portraits, and seated video interviews…but it's inept for runway fashion or candid wedding portraits.

It weighs (and costs) a lot more than the FA 50mm f/1.4, but that older lens is a full-frame "fast 50" for street photography and general use. The DA* 55 is portrait lens through and through.

Thanks for the kind words, Artie. I too have had my share of frustration with beautifully sharp but painfully slow focusing primes over the years-- even though AF tech has improved quite a bit I remain biased toward zooms for anything that moves fast

It seems to me that in the age of digital, manufacturers have more or less given up on the idea of small, fast, light, inexpensive prime lenses, which I define as no slower than f2 and no more expensive than $250 USD. When I look at current offerings, I'm very disappointed.

The Canon EF, RF, and M mounts all each have only a single fast, inexpensive prime, the 50 mm f/1.8s for EF and RF, and the 22 mm f/2 for the M mount. Nikon has two for their F mount, the 50 mm f/1.8 and 35 mm f/1.8, and one for the Z mount, the 40 mm f/2, which barely qualifies as inexpensive). This does not exactly inspire many people to buy in.

While all of these are admittedly high quality lenses, by every account, both Nikon and Canon really need to add at least one more inexpensive, compact prime to each of these mount systems. I'm aware that adapters may exist, but those are a kludge. Give us native lenses.

I would also note that f/2 is definitely considered "fast" for a lens, particularly for a portrait lens, as some of the most famous portraiture lenses for 35 mm film cameras fell into this category, such as Nikon's famous 105 mm f/2 DC and 135 mm f/2 DC lenses, and Canon's 100 mm f2 and 135 mm f/2. Of course, none of those fall into the categories of small, light, or inexpensive.

My point is really that is Canon can make a 22 mm f/2 for the M, then they can certainly do so for the EF and RF. If they can make a 50 mm f/1.8 for the EF and RF, then they can definitely do so for the M (though no one is really expecting new glass for M, are they). And if Nikon can make a 35 mm f/1.8, then why can't anyone else?

I'm renting several primes lenses to figure out what's fits my style and budget

That's probably the best approach to figuring out which lens is best for your needs. It's one thing to read about a lens and another to try it yourself. 

I'm partial to the 135mm focal length. I use the new Samyang AF 135mm 1.8 beginning a month ago. I've not found a flaw at all. I'm just wondering if it's natural to feel the way I do about a lens. It's a one-way love affair.

As long as you treat it right I'm sure the feelings are mutual.