Prime Lenses: Can you really zoom with your feet?

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There’s a common maxim touted in photographic circles, especially in online forums and message boards. It states that some of the limitations of shooting with a prime lens can be overcome by simply moving your body around. The idea of “zoom with your feet” or SneakerZoom, as it’s sometimes called, is often used as a panacea for those who think prime lenses are limiting in terms of what they can do compared to their zooming counterparts.

To a certain extent this is true. If you want to get closer to your subject you can just physically move your body if you don’t have a zoom lens, but doing so results in images that are not at all the same as using a zoom lens. Zooming with your feet is somewhat of a misnomer because zooming implies a change of focal length. But when you move around with a prime lens you are not changing the focal length at all. Instead, you are recomposing with your feet. In this article I’ll explore why this is a simple but significant difference using a few examples below.

Prime Lenses: Can you really zoom with your feet?

How lenses work

To understand how lenses work it’s important to know a few things. The focal length is a measurement of the distance between the optical center of the lens (the point at which incoming light converges) and the image sensor of the camera to which it is attached.

Many cameras come with what’s known as a kit lens. Most of those cover a relatively modest range of focal lengths, with the most common being about 18mm to roughly 55mm. At 18mm, the lens bends light in such a way that the incoming light converges on a point 18mm in front of the image sensor. This results in a field of view that is about 76 degrees wide. (Assuming you are shooting with a crop-sensor camera like a Canon Rebel or Nikon D3300. On a full-frame camera like a Canon 5D Mark IV or Nikon D810 it would be about 90 degrees.)

At 50mm, the angle of view changes to roughly 31 degrees. The practical implications for this are that you can simply fit more in the frame when shooting at a wider focal length versus a longer one. Take the example of photographing a tree, as you can see in the following illustration.

Prime Lenses: Can you really zoom with your feet?

Angle of view versus moving your feet

Shooting at 18mm would allow the photographer in this example to fit the whole tree in the frame, but unfortunately this photographer is using a 50mm prime lens that does not zoom in and out. At this point, you might be thinking, “No problem, just walk backwards to get the whole tree in the frame”.  My good friend Bob Slydell from the movie Office Space would respond, “Just a second there, professor.” While it’s true the photographer could walk backwards and reposition himself such that he could fit the entire tree in the picture, there are two problems with this solution:

  1. There is a pond filled with crocodiles right behind him
  2. He would still have a 31 degree viewing angle

No matter how far backward, forward, or sideways the photographer in this example repositions himself, the angle of view with the 50mm lens will still be the same. Theoretically, he could construct a raft and float across the pond in order to fit the entire tree in the frame. But doing so would result in a dramatically different picture than if he just uses a wider lens to begin with. Zooming with his feet, or in this case with a boat, will work to get a picture of the tree, but doing so will alter the other compositional elements of the photo.

An example

To see how this works, here’s a revised version of the image above wherein the photographer has retreated far enough to get the entire tree in the frame. In this example, there are five pinwheels behind the tree that are well contained in the wide-angle shot. While moving backward has solved the issue of getting the tree in the frame, the narrow viewing angle means that not all the pinwheels fit in the shot.

Prime Lenses: Can you really zoom with your feet?

The only way to solve this problem using a Zoom With Your Feet solution would be for the photographer to move way back such that the tree and all the pinwheels could fit in the frame. At which point the original subject (the tree) would be so diminished that the image wouldn’t be the same at all.

Real life examples

Of course, this is a theoretical example, but watch what happens when the same type of scenario is replicated in the real world. I shot the following three images using my 70-200mm lens. Watch what happens as the focal length, as well as the distance to the subject, changes.

Shot #1 – 70mm, from far away

Prime Lenses: Can you really zoom with your feet?

70mm, f/4, ISO 100

Can you tell what the subject is in this picture? It’s supposed to be the artwork in the middle–a boy fishing with his dog, carved from the trunk of a fallen cypress tree. The angle of view in this picture is about 34 degrees (I shot this on my full-frame Nikon D750), which is enough to capture lots of scenery in the frame. Notice how in addition to the boy and his dog you can also see trees, a building, and even some foreground elements such as a pond and grass.

Shot #2 – 200mm, from far away

Prime Lenses: Can you really zoom with your feet?

200mm, f/4, ISO 100

Standing in the exact same spot as before but zooming into 200mm has had a dramatic impact on the picture. Now the viewer’s attention is focused squarely on the carving, and the field of view is now limited to a much narrower 12 degrees. Note where the head of the carving is in relation to the building in this image: it is framed between two columns on the first floor above the ground, which is quite different from the next picture.

Shot #3 – 70mm, shot from close up

Prime Lenses: Can you really zoom with your feet?

70mm, f/4, ISO 100

This final photograph was made by zooming with my feet, I repositioned myself to be much closer to the tree carving. The resulting image is similar, in that the carving itself is roughly the same size as in the 200mm shot, but the field of view is 34 degrees because I shot this at 70mm. Even though the subjects are similar in shot #2 and shot #3, the pictures are entirely different!

The wider field of view in shot #3 resulted in an image with a lot of background elements that distract the viewer. The boy’s head is now positioned near the top of the building, despite the fact that my camera was the same distance above the ground. While the classic SneakerZoom technique has certainly worked to get my subject looking how I wanted, the end result is quite different from actually using a proper zoom lens.

Zooming with your feet is NOT the same

These examples show that while you certainly can zoom with your feet, doing so is not the same at all as zooming with a telephoto lens. When you move around you are not really zooming but recomposing. While this is not a bad thing, it is something to be aware of when choosing lenses or honing your photography technique.

As another example of this phenomenon, here are two pictures from a recent session I did with a local family. I shot the first one with my 70-200mm lens. It’s a traditional portrait-style image with a blurred out background with the focus squarely on the faces and upper bodies of both women.

Prime Lenses: Can you really zoom with your feet?

200mm, f/2.8, ISO 100

I then zoomed all the way out to 70mm in order to get a closer, more personal image of the two women. After changing to a 70mm focal length I had to walk much closer to the ladies, essentially zooming in with my feet, in order to get them to appear the right size in the frame. The resulting image feels entirely different, not just because they are sitting on the ground showing off their matching wrist tattoos, but because you can see that they are sitting in the middle of a green field strewn with autumn leaves.

70mm, f/4, ISO 100

Shooting at 200mm meant a highly compressed field of view with only a small slice of the trees and background visible. Whereas in the bottom picture you can once again see the effects of the wider viewing angle afforded by shooting at 70mm.

Different planes

One final example that’s necessary to illustrate this phenomenon, is when you and your subject are not on the same horizontal plane. In these situations, changing your focal length can bring you much closer to what you are trying to shoot, whereas walking around will significantly alter the scene, based on the foreground and background elements, as well as the angle from which you are viewing the subject.

Shot #1 – 70mm, from far away

Prime Lenses: Can you really zoom with your feet?

70mm, f/4, ISO 100

This image looks decent, but I didn’t like how the flags shared the frame with the building behind them, especially the chimney in the corner with the radio antenna. Since I shot this at 70mm I had a couple options to improve the shot; including zooming into 200mm or zooming with my feet to get closer to the flags. I started with the first option and was very happy with the result.

Shot #2 – 200mm, from far away

Prime Lenses: Can you really zoom with your feet?

200mm, f/4, ISO 100

Zooming with my lens gave me a much better picture. One that focuses entirely on the flag pole with no distracting background elements and a nice cloudy sky to help the flag pop out of the frame. One tradeoff is that the Oklahoma flag is no longer visible. I could have zoomed in only partially to 135mm if I wanted to include it, but I decided that the picture would be more impactful if it just had a single subject instead of two flags. After getting this shot I zoomed in with my feet to see if I could get a decent picture at 70mm by moving much closer to the subject.

Shot #3 – 70mm, shot close up

Look at how different this final image is compared to the 200mm version! While I was able to get the United States flag much larger in the frame, I ended up shooting from such a low angle that the flag pole itself draws almost as much attention as the banners it is holding. The Oklahoma flag is also visible in this version, which has the unfortunate side effect of creating an image that is unfocused and busy. There are now two subjects in the frame (three if you count the pole.) This leaves the viewer with a sense that the image is cluttered and unfocused. Zooming with my feet did allow me to get closer to the subject, but it altered the composition so significantly that the resulting image is unusable.

Conclusion

Hopefully, these examples will help you start to visualize why moving around is not at all the same as changing your focal length. Please understand that I’m not saying you should sell all your prime lenses and rush out to buy a zoom lens, though. I use prime lenses all the time, and by far my most-used lens is the Nikon 35mm f/1.8 for its size, weight, and sheer versatility.

My goal is simply to help you understand that when you are shooting with a prime lens you need to know that moving closer to, or farther away from, your subject does not have the same effect as actually changing the focal length. Once you understand that, you can start using this knowledge to your advantage. You can structure your photo techniques around this important limitation of prime lenses, and hopefully, take much better pictures as a result.

Read more from our Tips & Tutorials category

Simon Ringsmuth is an educational technology specialist at Oklahoma State University and enjoys sharing his enthusiasm for photography on his website and podcast at Weekly Fifty. He and his brother host a monthly podcast called Camera Dads where they discuss photography and fatherhood, and Simon also posts regularly to Instagram where you can follow him as sringsmuth.

  • Steve Baker

    That’s what I’ve said to someone when they said zoom with your feet. Thank you for clarifying this up.

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  • Gregory Andrus

    This is an incredibly helpful article, thank you! I think you just helped me to make a decision to finally get the 70-200.

  • Guilherme Palazzo

    Great explanation and examples. It’s not wrong to zoom with your feet, it’s just different, a good photographer should know when to use which.
    Actually, your explanation made me think a little bit more about crop factor. If I have a 1,6x cropped camera and want to take a picture similar to one taken with, let’s say, a 50mm on FF (aprox. 40° horizontal angle of view), I can’t use the same lens and walk back because all the reasons you said. But even if I change the lens to a 31mm (again, aprox. 40° horizontal angle) and make the picture in the same spot as the full frame photog, the picture I get will not be the same. So, even if the angle of view is the same, there is something more.

  • Dave Melges

    This is such an important thing to understand. Good article.

  • JvW

    One difference is the depth of field & hyperfocal distance at any given aperture: more DOF at shorter focal length.
    I don’t know, but another difference could be sensor size. The Canon 70D, for example, is 22.5 x 15 mm while the 60D is 22.3 x 14.9 mm. The 60D sensor is slightly smaller, so the angle of view at any given focal length will be slightly smaller too. Both sensors count as 1.6× crop factor.
    So a factor 1.6 (Canon) or 1.5 (Nikon etc) is not exactly 1.6 or 1.5.
    Anybody else?

  • DD

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  • Johann Kühn

    Perspective is also a very important thing to note. I’m into old cars, and take pictures for the local club (including shows). Using 50mm vs 18mm can make a huge difference (for example 18mm is great for putting emphasis on a long bonnet, while other pictures need a more natural perspective).

    Another thing about perpective: Using a long focal length has the (sometimes unwanted) side-effect of bringing the background closer, while a short lens moves the background further back (as also seen in the artwork photos).

  • Simon Geard

    Of course, “zoom with your feet” isn’t always possible… e.g. the pond of crocodiles you mentioned. I can’t fly or walk on water, so my feet won’t get my wide-angle lens any closer to the eagle flying overhead, or the interesting-looking buildings across the river, or the detailing on the roof that can’t be seen from a low angle. Conversely, I can’t see through walls or trees (or from the inside of a crocodile), so getting sufficient distance for a narrow field-of-view often isn’t an option.

    That said, this is why I love bridge cameras with a good zoom. The quality is usually good enough for my purposes, and the flexibility of a single device with a versatile lens is absolutely invaluable.

  • Frescarosa

    Interesting article for beginners, but you assume that someone who uses primes only has one lens…
    I mostly use primes but I have several lenses in my bag.
    I only zoom with my feet between 2 different focal lenghts…

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  • Frank Petrocelli

    Changing from one prime lens (like a 28mm) to another (like a 200mm) is the same thing as zooming. I don’t think the author meant zoom lenses only. He was referring to using a longer focal length from a distant position versus actually moving closer to your subject. Therefore, you can choose to keep your wider lens on and move up or stay where you are and put on a telephoto.

  • Going point, Simon. People sometimes forget about those Bridge Cameras but as you said they can really come in handy!

  • Thanks Frank. That’s what I was referring to, and I appreciate you mentioning it

  • Thank you!

  • I don’t think you’ll regret it. I shoot with 35, 50, and 85 primes as well as a 70-200 and while they each have their purposes that 70-200 is awesome 🙂

  • walwit

    This is why I’m here at DPS, excellent article Simon, keep doing this please.

  • Tex-S

    There have been serious online arguments on this issue. To keep the math simple, a 50mm lens behaves as a 75mm on a Nikon 1.5 crop sensor and like an 80mm lens on the 1.6 crop Canon sensor. That the field of view is altered has never been at issue. What is at issue is whether or not the overall depth of field and background blur are also equivalent to 75mm and 80mm lenses on full frame sensors. Extensive side by side results are lacking, but those tests I have seen suggest that the aperture number should also be multiplied by the crop factor to predict DOF and background results.

    A 50mm lens, at equal aperture and distance from the the subject produces a greater DOF than 75mm or 80mm. Imagine taking the same shot at 50mm and 80mm focal lengths on the same Full Frame camera. The 80mm will show greater blur in the out-of-focus areas, and cropping the center area out of the 50mm image to reproduce the FOV of the 80mm does not suddenly add more blur.

    So a 50mm lens on a 1.6 crop, set to 4.5 aperture will approximate 80mm f/7.3 0r f/8 on a full frame.

  • Simon Geard

    It’s the usual balancing act. Bridges don’t offer quite the same quality as a DSLR (optics are usually good, but even the best have only a 1″ sensor), and they’re not as versatile as a bag full of lenses, so a lot of pros tend to overlook them.

    But the quality is often good enough, and having a camera with a single versatile lens is a real boon in some situations. They’re especially good for travel, where keeping the weight and bulk down is important, and where you’re constantly switching between wide-angle and zoom depending on the sights in front of you…

  • pete guaron

    It’s a case of “it all depends”. It depends on what you are comparing. The traditional mantra that I’ve read over the years revolved around an alleged quality difference between zooms (so often, “kit zooms”) and primes. We’ve moved forward during those years, and for most purposes, provided you select your lenses with Image quality in mind, there’s precious little difference in the optical performance of “good” zooms and primes. For most photographers, the difference would scarcely be noticeable.

    At the top end of the range, that turns around. I am unaware of any zoom that could come within a bull’s roar of the performance of one of Zeiss’s Otus lenses, and I have serious doubts whether there are too many that could match the performance of one of Sigma’s growing range of ART primes. But that edge comes at a price – in weight, in dollars, and in convenience. And the question you need to consider is simple – IS that edge in image quality worth the added cost, weight and inconvenience?

    Unashamedly, I use both. And my selection depends on why I am taking the shot – what is it for? – what do I want to achieve? Stationary subjects may favour primes – action shots often call for a zoom, to deal with the range of movement of the subject – and other different types of photography generate their own reasons for choosing a particular lens.

  • Rohinton Mehta

    A very good write-up. Thank you.
    I feel there is a small ‘correction’ required in your definition of focal length. You have
    mentioned that focal length is the distance between the optical center
    of the lens and the film/sensor plane. The definition of focal length is
    true only when the lens is focused at infinity. When you focus closer,
    the focal length actually reduces.

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  • Karen Garay

    Very helpful as always, I am just starting to use prime lenses and this is exactly what I needed to know, before I knew that I would need it. I very recently purchased a bundle with an 85mm f3.5 macro and your favorite 35mm f1.8. The 35mm was labeled portrait but I’ve been using it for lots of landscapes and they’re mostly better than what I got with the kit lens (18-55). I love your articles and share this site all the time, keep up the good work!

  • Ken McDougall

    Good article, I learnt something new!

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  • Brian Gibson

    There is one word which seems to be ignored by the “zoom with you feet” brigade, and is also ignored in this article, and that is Perspective.
    This whole article is about perspective, yet the word is not mentioned.
    As soon as you change your viewpoint you change the perspective of a scene.
    If you stay in the same spot and zoom the perspective of the scene never changes.

    Many people seem to think perspective is a lens function (“I like this lens because of it’s perspective”) – it is not. A lens does not create perspective, that is established by the viewpoint.
    So the next time someone says “zoom with your feet,” then say, “I like the perspective from this viewpoint and I don’t want to change it.”

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  • John Blanke

    This article is the best written and best illustrated on this topic that I have read. For years, I have had photographers discuss and explain the Sneaker Zoom vs. Zoom Lens issue with me and I never really could grasp the concept this thoroughly. Thanks for writing it so well and succinctly and illustrating it so vividly as to make it totally intelligible even to a dolt like me!! Time well spent reading and re-reading this article. I really learned something I wish I would have known many years ago.

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