What Is Mm In Photography?


Good photography, as any professional will tell you, goes beyond catchy compositions and beautiful model. It engulfs the technical mastery of your tools, primarily your camera and lenses. In particular, understanding ‘mm’ or millimeter in the context of camera lenses is similar to missing out on understanding every word Shakespeare ever wrote if you’re an English literature major – a bit dramatic, but you get the picture! Let’s unravel this mirth shrouded in millimeters in a way that’ll have you saying “a millimeter a day keeps the frown away.”

Millimeter, in photography speak, pertains to the focal length of your camera lens. Think of it as a telescopic view into the realm of your captures. Ah ah, don’t get carried away; we don’t showcase the universe here, but we can certainly show you how pieces of it can be importantly defined. It’s a simple concept, but its impact on the quality and aesthetics of your photographs is enormous.

Understanding the meaning of ‘mm’ in photography, especially as it relates to lenses, can be a game-changer for both budding and mid-level photographers. It’s like knowing what each button on your spaceship can do before you ignite the engine – less chances of accidental teleportation. This understanding paves the way for more intentional decisions when capturing your masterpieces and aids in selecting the right lens for your photography needs.

Remember those family vacations, where your 18mm lens made everyone look estranged, spread across the frame like customers queuing two meters apart at the supermarket? Or those attempts at wildlife photography, when the lion turned into blurry smudge on your 35mm lens? With an understanding of ‘mm’ in photography, those days will soon be laughable memories of the past. Can’t wait? I assure you, it’s going to be well worth it. Let’s delve deeper!

The Meaning of mm in Photography

To truly understand the concept of millimeters, or “mm”, in photography, let’s begin by establishing its basic definition. In the context of camera lenses, the millimeter specification refers to the focal length of your lens, which directly impacts the captured field of view. For instance, a 50mm lens has a focal length of 50mm. Now, let’s translate this to practical terms.

Think of the camera lens as a window through which you observe the scene. Lower mm measurements denote a wider ‘window,’ allowing you to capture more of the scene, while higher mm lenses offer a narrower, more focused view. The effect can be metaphorically likened to looking out of a large bay window versus peering through a small porthole on a ship.

Here’s a concrete example to clarify this further. A wide-angle lens, like a 24mm, provides a broad perspective—ideal for sweeping landscape shots or spacious interiors. On the other hand, a 85mm lens offers a targeted field of view, perfect for close-up portraits or spotlighting a single subject.

Another critical aspect tied to the mm specification is the lens’s magnification power. A low mm lens has less magnifying power, capturing a wide view but with smaller appearing subjects. Conversely, a high mm lens has more magnifying power, capturing a condensed field of view with larger appearing subjects.

So in essence, the mm specification of your lens is like your photography paintbrush, helping you paint each frame with different strokes. Understanding this concept will give you the power to control what and how much you capture in each shot. And let’s be honest, who doesn’t want that kind of artistic authority?

How mm Affects Photographs

The ‘mm’ or millimeter measurement on your camera lens is not just a number; it’s a transformative storytelling tool that can dramatically influence the outcome of your shots. It comes into play in various photography elements namely, depth of field, distortion, perspective, and focal length.

Let’s talk ‘depth of field’ first. Depth of field refers to how much of your photo is in sharp focus. A lens with a lower mm, let’s say 24mm, will generally provide a greater depth of field—meaning a larger part of the scene will be in focus. This is best suited for scenes from sweeping landscapes to bustling cityscapes where you want most, if not all, aspects of the scene to be in focus. Conversely, lenses with higher mm, like a 200mm, will give you a shallow depth of field—ideal for that perfect portrait where the subject is in sharp focus, and the background is a gorgeous, aesthetic blur.

Next up, let’s touch on distortion and perspective. Lower mm lenses, often called wide-angle lenses, may introduce some level of distortion around the edges of your frame as they try to fit more of the scene onto the sensor. This can give a unique perspective, especially in architectural photography where buildings seem to stretch high into the sky, a style known as ‘forced perspective.’

On the other hand, higher mm lenses or telephoto lenses compress space, making objects appear closer together than they actually are. Peachy for those stunning wildlife shots where you want to capture the lion without becoming its lunch.

And finally, let’s not forget about ‘focal length’—the distance between your camera’s sensor and the convergence point inside your lens. Simply put, a higher mm means a longer focal length, and consequently, more zoom; while a lower mm signifies a shorter focal length and wider view.

To sum up, your choice of lens mm impacts how your photograph appears in relation to focus, perspective, distortion, and range. Remember, photography is as much about what you leave out as what you include. Playing around and understanding the impact of differing lens mm is key to mastering this. So on your next photo venture, whether it’s capturing stunning sunsets or your grandma’s smile, keep the ‘mm’ in mind—it is, after all, not just a number!

Choosing the Right mm for Your Photography

Choosing the correct millimeter or mm range for your lens can feel like navigating through a maze without a map. However, keeping certain factors in mind can help to simplify this process.

Firstly, consider the type of photography you’re most interested in. Landscape photographers might opt for wide-angle lenses, typically between 10mm – 24mm, which offer a larger field of view. On the other hand, portrait photographers might lean towards lenses around 50mm – 100mm, leading to flattering perspectives and ideal subject isolation.

Your budget also plays a significant role. Lens pricing varies greatly based on optical quality, build, aperture capability, and, notably, the mm range. For instance, a high-quality 24-70mm zoom lens can set you back a tidy sum, while a simple, fixed 50mm lens, also affectionately dubbed the “nifty fifty,” can be more budget-friendly and is often touted as a must-have in photographers’ kit due to its versatility.

Another important factor is your preference for specific photographic effects. For example, if you’re a fan of dramatic, stretched perspectives, a lens with a smaller mm, such as a 14mm ultra-wide lens, might be your go-to. Conversely, if crisp subject detail and blurred backgrounds are your thing, you might lean towards a 85mm or higher mm lens which provides a shallow depth of field.

Let’s not forget about some popular options: The 35mm lens is appreciated for street photography due to its balance of depth and breadth. Meanwhile, the 70-200mm lens is a favorite amongst wildlife photographers, thanks to its zooming capabilities.

The world of ‘mm’ opens an array of creative choices, altering your view of the world as seen through your camera’s viewfinder. So, whether you’re capturing the grandeur of a mountain range or the twinkle in your subject’s eyes, remember, it’s the correct mm range that turns those creative visions into captivating photographs. Don’t be afraid to experiment, play around, and, most importantly, have fun while doing it! After all, photography, much like life, is about finding the perfect perspective.


In unmasking the meaning of ‘mm’ in photography, we’ve embarked on an exploration of how this small, overlooked element plays an integral role in shaping our photographs. It is more than just numbers etched on a lens; it influences perspective, depth of field, distortion, and – most poignant of all – the narrative of your visual story. As we’ve seen, the choice of mm dramatically impacts what gets included or excluded from the frame, holding the power to create dramatically different images in otherwise identical environments.

Understanding ‘mm’ is pivotal for stepping up your photography game. It not just assists you in choosing the right lens for the right occasion, but also helps you understand the artistry behind every picture. From breathtaking panoramic landscapes commanded by low mm lenses, to the intimate detailing of portraits through high mm lenses, understanding this simple concept is the key to unlocking new potentials in your craft.

However, it’s important we don’t lose sight of the fact that, like so much in photography, understanding ‘mm’ isn’t simply a matter of reading an article and digesting some facts. It’s a practical concept, inviting hands-on experience and experimentation. It’s when you shuffle between a 24mm to a 50mm, then to a 200mm lens, observing the shifts in your frames, that you truly grasp the distinct influence each lens has on your composition. Time spent behind the lens, fiddling with the mm and noticing the changes it casts, is what makes this learning curve worth climbing.

While we dissect technicalities, let’s remember that photography isn’t an exact science but an art form. The ‘correct’ lens isn’t chosen by rigid rules but by your vision as a photographer. Mastering the concept of ‘mm’ is meant to facilitate your unique perception, not confine it. So, as you gear up to tackle photography with the newfound insights from this article, remember to let curiosity lead the way, and brace yourself for a deluge of ‘aha’ moments. Remember, it’s the subtlety of these small elements that work their magic to create a striking photograph.

The Creativv
American digital marketer and founder of TheCreativv.com with over a decade of experience in event, travel, portrait, product, and cityscape photography.