Prime Time: Focus on Fixed Focal Length Lenses

Prime lenses are designed for exceptional imaging at a single focal length. Unlike zoom lenses that easily span a given focal range and variable field of view with a twist of the zoom ring, the field of view and focal length remains constant. If you want to take in less of the surroundings with a given prime lens, you’ve got to physically move closer, and to take in more of the scene, you’ve got to back up. But of course, as you move, the angle of view remains the same all the while.


It is true that switching to a prime for the first time may take a serious degree of adjustment for many photographers who’ve only worked with zooms, and the flick-of-the-wrist compositional versatility they offer. It is true the overall quality of zoom lenses has increased significantly over the past three decades. But there is still something, a certain charm, or a certain shift in the photographer’s eye, when the optic of choice is a single focal length lens.

Sigma currently offers 22 prime lenses, from a 4.5mm Circular Fisheye through a supertelephoto 800mm F5.6. Whether it’s a DN lens for mirrorless compacts, or DC and DG for APS-C and full-frame DSLRs, every one of these lenses is designed and optimized for exceptional performance at the singular focal length. Also of course, the trio of compact DP Merrill cameras, all feature F2.8 prime lenses, paired with the incredible Merrill Generation Foveon sensor.

The individual imaging aesthetics of, say, the circular 180º image of the 4.5mm F2.8 EX DG HSM Fisheye, the life-sized macro detail of the 180mm F2.8 EX DG OS HSM, and the amazing reach of the 500mm F4.5 EX DG HSM are obviously markedly different–but whatever the focal length, the overall prime lens photography experience is similar. When the prime lens is paired with the camera, you’ve got what you’ve got until you change lenses. Want to zoom in or out? That’s what your feet are for!

Beach Flower, seen through the Sigma 35mm F1.4 DG HSM | A lens. 1/500 F4.5 ISO 100. Sigma offers several fast F1.4 primes with exceptional sharpness, even wide open for the signature fast prime shallow depth of field feel.

It can be a bit frustrating at first, and if you hand a camera with a prime attached to most casual photographers, the first question they’ll have is: “where’s the zoom ring!” But with a little patience, practice, and experimentation, the prime lens experience can help you grow visually as a photographer.  It can help you recompose your scene, based on the overall angle of attack to the main subjects, distance to subject, most important ground elements, and so on.

A ring of beach rocks seen through the Sigma 15mm EX DG HSM Diagonal Fisheye with the horizon line near the center of the frame.
And here is the same scene from the same spot, but with a different composition to place that line of rocks and sky nearer to the edge of the frame to amplify the signature Diagonal Fisheye field distortion.


You’ll soon find repositioning and relocating yourself to recompose and reframe the scene while keeping the same field of view offers a very cool creative alternative to the casually recomposed zoom. And of course, from a project perspective, there’s a wonderful visual unity in any series of deliberately grouped photos all made with the same prime lens. For example, it might be the warped sense of space offered by a full-frame diagonal fisheye, or the razor-thin depth of field offered by one of our fast F1.4 primes, or a number of similar, but not identical tiny things all captured with the same life-sized magnification of one of our five F2.8 prime macros with 1:1 reproduction that ties a project together.

A lightning bug fills the frame at near life-sized magnification through the Sigma 70mm F2.8 EX DG HSM Macro lens. 1/100 F10 ISO 100, with the Sigma Macro Ringflash attached for directional lighting.

A good way to test to see if you’ll be comfortable with the prime lens experience is to spend an entire session with one of your zooms locked at a favorite single focal length that’s similar to the prime you’re interested in–can you truly spend an entire photo session at that single focal length? And the next? And the next? If you’ve got more lenses in your bag, treat it like a true prime and swap out to a different zoom lens should you want to mix it up from a focal length perspective.

The 60mm F2.8 DN | A lens equates to a 120mm F2.8 tele on the mirrorless micro four thirds camera. I’ve got to move closer to, or farther from these blooms to change the feel of the image. 1/1250 F2.8 ISO 200 on the E-PL2.

You may be surprised at how easy it is for you to make the prime lens adjustment in your mind; or you may find that what you really want is a hot new zoom lens that’s got a longer zoom range, or faster constant aperture or such. Either way, there’s a Sigma lens that’s right for you.

While many of Sigma’s zoom lenses offer macro settings, the 1:1 magnification (life-sized) offered by the five F2.8 prime macros in the lineup offer greater overall magnification. These pine needles on a forest floor were just inches in front of the 70mm F2.8 EX DG Macro lens to create a dramatic separation of foreground and background elements, even stopped all the way down to F16!

With a prime, when you can’t change your location and can’t recompose by zooming, you are forced to really pay attention to every element in the image. If the main subject is small in the frame, overall composition is very important. If the whole subject cannot fit in the frame, you’ve got to choose what details best tell your story and where to place your edges.

Here’s the Sandy Hook Lighthouse at a distance with the Sigma DP2 Merrill, a fixed lens compact with a standard angle of view. In order to make the buildings and lighthouse appear larger in frame, I’ve got to walk across that grass in the foreground to get physically closer to the items of interest in the frame.
Here, I’ve walked closer to the lighthouse and tan building to make everything appear larger in the frame. The angle of view through the DP2 Merrill’s lens remains the same.
Now, I’ve again walked closer and changed my location to avoid making a photo of nothing but that big bushy tree that was straight ahead on my path in the last two pictures. Remember, with a prime lens, you zoom with your feet!


For example, If you’ve got the 85mm F1.4 EX DG HSM lens, and you’re at the edge of a dock, and that docile pelican you’ve been framing for up-close details on the nearest piling suddenly gets spooked and flies twenty feet away to a farther perch, you’ve got to change your overall visual expectations. Same goes with a longer telephoto lens and sports. It is great to have the long, fast, sharp reach of a prime telephoto, but sometimes when the action is coming right at you, you’ll find yourself overlensed. But it’s always best to focus on the shot you’ve nailed with tight framing or excellent composition and not worry too much about the ones you’ve missed!

Is it time for a new prime? Here’s a video explaining the strengths of primes, and constant- and variable-aperture zooms to help you find your next lens!

Published by

Jack Howard

Jack Howard is a lifelong photographer and author of two editions of the how-to book, Practical HDRI. Based in Central Jersey, Jack's go-to photography spots are backroads and beaches of his home state. He loves to travel far and wide with his wife and daughter, visiting national parks, museums, tropical islands and more along the way.

One thought on “Prime Time: Focus on Fixed Focal Length Lenses”

  1. I like prime lenses. I don’t use them enough, but I’d like to buy a few, so I could. But I am not happy with the way Sigma is expanding their line of primes. As a company Sigma seems to be focusing too much on the A series lenses. I’d like to see some more S series lenses. I come from Canon equipment, and I had L series lenses. They were all weather sealed, and that is one of the big selling points of the L series lenses. Sigma’s S series lenses share this same selling point, but with only one lens offered, I find it difficult to feel proud or hopeful that I will have a comparable range of lenses to choose from for my Sigma cameras one day. Why is the new 50mm f1.4 not an S lens? Why is there no S series 24-70mm f2.8 OS lens yet? Why was the new 24-105mm f4 OS not launched as an S lens? I would very much like to see Sigma introduce a 24mm f1.4 S, but I fear we will never see a full line of S lenses. I do like that Sigma has been stepping up with their lens line-up, creating the A lenses that we now have available, and I suspect it is being done in order to “migrate” Sigma users from the new A lenses into the S line-up that may be coming in the future, but that just makes me not want to buy anything good. I find it sad that Sigma has not followed their introduction of the SD1, a weather sealed camera, with a line of weather sealed lenses. I would REALLY like to see a 135mm f2 OS lens introduced into the S line along with a 35mm f1.4 S and a replacement for the aging 70mm f2.8 macro in the form of a 70mm f2.8 macro S lens.

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