Why Lens Compression Is Important for On-location Portraits

Why Lens Compression Is Important for On-location Portraits

Choosing a lens which will give you desired results for a particular portrait assignment is an integral part of being a photographer.

There are many factors to consider when making this choice. Do you prefer zoom lenses that allow you to quickly change between focal lengths, or do you lean towards prime lenses, which usually offer wider apertures at a single focal length? Are you a photographer who prefers standard lengths such as a trusty 24-70mm lens or perhaps a nifty 50mm prime? Or would you rather experiment with something a bit different, such as a 200mm macro or a 12mm super wide?

Shorter lenses can be used handheld without a tripod and not yield any motion blur from hand movements at longer exposure times. For example, a 30mm lens might not have any hand movement motion at 1/60 of a second, but a 150mm lens at 1/60 s might have some motion blur. You can read up more on this elsewhere, but for now, you might have to take my word for this example.

As with any creative choice you make, it’s not so much about a wrong or right answer, but rather working with a final set of parameters in mind. For example, if you were photographing corporate headshots for a fairly conservative client, such as a law firm, you might want to use a standard lens length such as 85mm. Instead, if you were photographing avant-garde garments for a fashion editorial, you might choose to include a few really wide shots, such as on a 12mm, to really create a sense of mood or lean into the feeling of the clothing. Finally, if you were photographing a wedding, having a zoom with you might better allow you to zip in and out of the action to offer closeup images of intimate moments along with wide shots that show off the overall action of the couple’s perfect day.

Lens Compression

One factor that often gets overlooked when choosing which lens to use is lens compression. This phenomenon is more noticeable when working on location. There may be a few instances where it might also need to be considered for studio photographers. 

As an aside, I have shown an example with images I have taken below. This might be easier to consider if you do this exercise yourself, though. If you do choose to try this, you will need either a zoom lens or several primes. I have shown which focal lengths I worked with, but these are suggestions. So, if you don’t have an 85mm focal length, you might opt for something slightly longer or shorter. But for the series to work, you will need several focal lengths.

Lens compression refers to how compressed the image looks. To clarify, this means that lens compression is how close the background appears to the subject. The key word here is "appears." In this phenomenon, the subject does not move.

In this example, I framed the first image on the 30mm lens. I made sure the subject filled up most of the frame. Next, I used a 55mm focal length; the subject did not move. Instead, I stepped back a bit so that the framing of the subject was similar to the first image. I continued this with longer and longer focal lengths. The subject did not physically move within the space for any of these images. Instead, as mentioned, I stepped farther and farther back away from the subject for longer focal lengths. The key to this series is that I made sure that the subject filled up a similar amount of space in each image.

You’ll notice that I didn’t consider the background in my composition. To reiterate, I made sure I composed the image with the subject filling up a similar amount of space within the image. So, when I had a longer lens, I stepped farther back. However, even though the subject didn’t physically move within the space, with each progressively longer lens the background "appears" to move closer to the subject.

Conclusion

It’s an important bit of information to know for the few cases where you might actually use it or need it, for example, if you were shooting a portrait of someone with a landmark in the background. If you wanted the landmark to appear closer and fill up the frame of the image, you might consider using a longer lens while taking a few steps back yourself so that the image is more compressed.

Alternatively, this technique might offer an avenue for more creative compositions. For example, if a subject were in front of a landmark such as a house, you might reconsider how you photograph such a composition. Instead of positioning the subject close to the house and using a short focal length that distorts both the house and subject, as short focal lengths tend to do, you may consider positioning the subject a fair distance away from the house and using a longer focal length lens. Thus, this would compress the image so that the house appears closer to the subject and neither the house nor the subject are distorted. 

Ali Choudhry's picture

Ali Choudhry is a photographer in Australia. His photographic practice aims to explore the relationship with the self, between the other, and the world. Through use of minimalist compositions and selective use of color and form he aims to invoke what he calls the "breath". He is currently working towards a BA (Honours) in Photography.

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38 Comments

"You’ll notice that I didn’t consider the background in my composition." Yes, but it does go along with compression. Another change in perspective also occurs. In the first photo, about half of his head is above the roofline of the building behind him. By the third photo, the top of his head does not come up as high as the top of the tree in front of the back ground. Composition is not important to make your point about compression, but it is something to consider.

Thank you for a great summary of the article!

I know that for a lot of people 85mm is practically sacred, but personally I love the look of 100mm and 160mm (more the former). Mind you, I'm not a portrait kinda photographer.

I remember years ago seeing a doco where the photographer was doing an outdoors fashion shoot at 200mm. Assistant in contact with a walkie talkie whilst directing the model and moving the reflector. Seemed a little strange, but considering it was for a major publication the photographer must've known what they were doing..

I'm "a lot of people"! I love the 85mm!

But it's also fun to try different ways of doing somethings, such as the 200mm example you gave!

Fstoppers 2016: "Lens Compression Doesn't Exist"
Fstoppers 2018: "Lens Compression Doesn't Exist - Here's Why"
Fstoppers 2023: "Why Lens Compression Is Important"

https://fstoppers.com/originals/lens-compression-doesnt-exist-147615

https://youtu.be/_TTXY1Se0eg

Great work Ali. I like last photo the best. I think. It is probably at 160mm focal length. It is clear of all distractions in the background. I appreciate the article and your effort. Thanks very much

Its a pity you did not read some of the many articles about how compression is a myth. Fstoppers even ran a few articles about it. Lee Morris did some interesting experiments to prove the point. What changes is the field of view and the camera's distance to the subject. As demonstrated many times in various online articles, that's all there is to it. https://cdn.fstoppers.com/media/2016/10/13/sequence_01_progressive_5fps_...

Agreed. And to add to the topic, these days when we have access to high resolution sensors and very sharp lenses one can in many cases crop instead of using the ideal focal length.

Understanding basic optical physics doesn't make you a pro photographer. Not understanding basic optical physics doesn't make you not a pro photographer. Few people can explain how an air conditioner works. And yet, we can all use one.

I wish photographers who do understand basic optical physics stop throwing tantrums and either 1) keep it to themselves, or 2) patiently help others.

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Edison,

You are quite correct. I believe that apparent compression comes from the perspective that we shoot from, and not from focal length. Using terms accurately and precisely can help to keep anyone from having a misconception about what causes the apparent compression.

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I LOVE lens compression, as well as zooming with my feet, and the exposure triangle. I use them regularly.

I especially LOVE how when these terms are used, sometimes, sometimes, you get these ill-tempered kids, guised as adults, throwing a tantrum over something so trivial. lol smh:D

You left out your love for the “medium format look!”

There is no such thing. Now, that's a myth. :P

Ali, if you consider compression to be a "flattening" of the image field from 3D to 2D then I agree with you and the test demonstrates it well. The compression is the result of the combination of changing lens focal length AND changing lens position simultaneously. In film school, everybody I knew referred to this phenomenon as "lens compression" because we only considered what we were doing in practice. We only cared about how we were using it in the real world. But film school is different from engineering school and the online world is populated by people that prefer theory over practice. In theory, all lenses act according to the same scientific principles so there should be no differences in compression between them. That's why so many people think that lens compression is a myth. My thinking is that lens compression is real in the university's photo program while still being a myth at the university's engineering school.

I agree. It is the results that matter, and the result is perceived compression. If you said it is cold outside. I could say you are wrong. Cold doesn't exist, but heat (transfer of kinetic energy) does exist. However, I would agree with you that it is cold outside. Cold does exist in the form of perception. It is our reaction to an uncomfortable, low level of heat.

As to the cropping comment, not everybody has a high megapixel camera. Even if you have one, you have to take the means of display into account. It is fine for smaller displays of an image. Cropping also would work for large displays viewed from a sufficient distance, such as billboards. But a large print hung where viewers can get close to it, can take just so much cropping of the original image before noise etc. shows up. Why not use a longer focal length to get the effect, and use all of the megapixels you can? Be it from your old 8mp DSLR, or your new 100mp wonder camera?

Great points and I especially like the hot/cold analogy

Great input Mike and Michael. This is why I emphasized the word "appear"; the images are certainly more compressed and flatter with the subject-background relationship. Similarly, Lee uses the word "perspective" in his video and article.

Time was when I used a selection of lenses. A lot of the time, out in the field, these days I use zooms.
Why? Because zooms have come such a long way, that from a practical point of view there's not a great difference in the results you get.

When it really matters, it's a shot that needs - and gets - careful planning. And the selection of a fixed focus lens is commonly part of the outcome of that planning process.

So I have a range - some zooms - some fixed focus - some full frame - some half frame.

That said - I agree whole heartedly with the thrust of your article. The choice of focal length makes or breaks a portrait. And not just portraits, either.

Those saying that "lens compression is a myth" are the ones perpetrating a myth. What is called "compression" is the appearance of bringing background elements closer to foreground elements. It is absolutely a thing and we can see the results all of the time.

https://www.youtube.com/watch?v=SvWUkA1s_D8&t=195s

Is the moon in the sky really this huge in comparison to a human? If the answer is no--obviously--than the only thing that can be ascertained is that the lens created the appearance of the moon being closer to the subject; compression.

Buy, yeah, don't believe your lying eyes.

Daniel, it is not the lens that creates the apparent compression. It is the perspective. If I am very far away from that woman, then she and the moon will be those sizes, relative to one another, because of the distance I am viewing them from, not because of the lens I am pointing at them. This has already been explained and illustrated countless times, and I am surprised that you still do not understand the role of perspective and distance in this.

Pedantic nonsense. You're not going to get that effect with a 50mm lens no matter what. Again, don't believe your lying eyes.

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You will get exactly that effect with a 50mm lens, or with any other focal length. My eyes would see exactly the same size ratio between the moon and the woman no matter what focal length is used, if shooting from the same position. How is it that you can frequent photography forums and read about photography, yet not understand this?

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Not unless you cropped an absurd amount; beyond what would produce an acceptable image. I think that you know this, but you're just being willfully obtuse hanging on to pedantic nonsense. When trying to achieve an aesthetic of a larger background in relation to the subject, a telephoto lens will absolutely do this. It's a compression EFFECT.; a distinctive impression to quote Merriam Webster.

That means you can use a long lens to achieve the effect of compression. Or, you could use a 50 mm lens and crop in an absurd amount and produce an image that's a pixelated garbled mess because, after all, there's no such thing as lens compression.

That's just stupid.

To use an analogy, I can set up a powerful flash, use camera settings and make an image taken in the middle of the day appear to be night. In EFFECT turning day into night. Now the absurdly pedantic among us will point out, "Well, you aren't actually turning day into night. C'mon, now!" They think they've proven how uber smart they are to people, but in reality, the rest of us are just rolling our eyes at the absurdity.

At the end of the day, you can use focal length to produce a compression effect and thus treat it and use it as such, and even, God forbid, refer to as such.

How is it that you can frequent photography forums and read about photography, yet not understand that you can use different focal lengths and camera settings to achieve different effects; including that of compression?

But, since you seem to believe your own nonsense, I'll go ahead and allow you to have your last word.

What you say in the above comment is correct and you used the words according to their actual and literal meaning. Thank you for that.

Yes, of course you need to crop extensively. But when you do, you get the same "compression". Yes the image quality would be unacceptable, but it shows that focal length is not the factor that produces the apparent compression. This is how experiments are conducted to determine what really affects things - we do experiments to eliminate factors, so that we can determine with absoluteness the one factor that is actually producing the effect.

I am trying to make sure that things are worded very precisely, while you seem to be more interested in a practical working knowledge of things, even if it comes at the expense of being incorrectly worded. To me, semantics are everything.

I get the impression that precise wording and semantics are not as important to you as they are to me. And that is okay. But don't shoot me down for my nit-pickiness and insistence that everything be technically precise. Being correct is really important. Being precisely correct is often preferable to being likable or relatable or helpful.

Daniel Medley asked me,

"How is it that you can frequent photography forums and read about photography, yet not understand that you can use different focal lengths and camera settings to achieve different effects; including that of compression?"

Well, Daniel, I actually do have a rather comprehensive understanding of the effects of focal length and perspective. I have written about the topic extensively, and given a talk on the topic at a photography club some years ago. I have even done experiments to prove that it is the perspective that produces the size differential of a foreground element and a background element, relative to one another.

I think that we both think the same thing when it comes to this stuff, but you are okay with using figures of speech that may not be literally correct, while I am insistent that all words used be correct and precise, as one would expect in a dissertation or a formal written testimony.

"That means you can use a long lens to achieve the effect of compression. Or, you could use a 50 mm lens and crop in an absurd amount and produce an image that's a pixelated garbled mess because, after all, there's no such thing as lens compression."

Your example is indeed impractical, so let me give you a more practical one: if a photographer stands in one place and switches between a 200mm, 300mm, and 400mm lens, or zooms with a zoom lens, and believes they will get a different perspective due to "lens compression" they are wrong. They would have to actually move their position.

You're not doing them any favours in achieving the shot they want by mistakenly telling them that compression is due to their lens. They'll never get the shot they want, and they'll never understand why.

There really is a 'language of photography" and it's definitely not pedantic. Some of us went to film school and decided not to be engineers for exactly these kinds of reasons. I can't even begin to recall how many times online article writers and bloggers have told me that I didn't know something I did know just because the language use was different.

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I don't mind language that is different, as long as it is precise and accurate and not some loose, sloppy everyday vernacular that you would hear in a diner or on the street.

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You're loose and imprecise when using the word "perspective." In photography, perspective is related to how view camera movements or tilt/shift lenses control distortions of the subject plane. Lens compression is caused by the distance from the lens plane to the subject plane and has nothing to do with camera movements. Perspective is also is used to describe the appearance of depth in composition, but that can be created a multitude of ways and lens-to-subject distance is only just one option.

No I am not loose and imprecise. Perspective means the exact point from which the photo is taken. That is all it means. You saying that it means something different than that or something more than that doesn't make it so.

The exact point from which the photo is taken is usually the film plane or the sensor plane, but that's a different topic.

The topic we're talking about is perspective. I don't actually mind if you call the position that the photo is taken "perspective" because that's how it's commonly used by article writers, bloggers, and youtubers etc. But this is a dumbed down version of what perspective really is in photography. A correlation mught be made with how people often say portrait or landscape to refer to vertical or horizontal orientation. It's imprecise because a portait could be horizontal or a landscape could be vertical. But we accept this kind of terminology because we basically know what they mean when they say it.

The way you're using perspective is to refer to a combination of the orientation of the lens plane /lens axis plane to the subject plane. It's not the same as perspective even though it can control perspective. For example, if the lens plane were to change positions (move forward, sideways, or backwards) relative to the subject plane, then there would be a different lens position and possibly a different perspective. But, if the lens were to stay in exactly the same position relative to the subject plane while simultaneously shifting the lens axis plane (tilt upwards, downwards or sideways) then the perspective would change even if the original lens position (relative to the subject) didn't move at all. The change in perspective due to the lens axis position is what causes or corrects effects like "keystoning" and it can happen without moving the original camera position at all. I understand that this is technical and can be difficult for most audiences to follow. That's ok because it's a different level of understanding from what is most common.

Perspective is a big topic and I'm only mentioning a small part of it, but this small part is what you're obliviously referring to as the whole thing. You're using a dumbed down version of the word the way that it's been made easily accessible to a wide audience. Just for the record, I don't care if photographers use terms loosely because not everybody is an expert and they don't have to be.. However, it's total blatant hypocrisy for you to correct others for being imprecise while simultaneously being imprecise yourself.

Technically, perspective has nothing to do with optics or lens position. It has entirely and only to do with the position of the recording medium, a.k.a. sensor or film, positionally, in relation to the subject & scene being recorded.

What you're referring to is the "station point" in perspective:
https://en.wikipedia.org/wiki/Station_point

Here's a quick video of how the station point works in perspective:
https://m.youtube.com/watch?v=XYrAkcEs6GQ&t=2s&pp=2AECkAIB

In photography, the station point is often referred to as the camera position, lens plane, lens axis plane, vantage point, viewpoint, angle and point-of-view etc.

Perspective is NOT the station point. Perspective is made up of multiple points including vanishing points. The number of vanishing points determines if an image is one-point perspective, two-point perspective or three-point perspective etc:
https://en.wikipedia.org/wiki/Perspective_(graphical)

Five-point perspective (aka fish-eye perspective):
https://en.wikipedia.org/wiki/Curvilinear_perspective

Perspective is also made up of lines and planes:
https://en.wikipedia.org/wiki/Perspective_(geometry)

In photography, perspective distortion occurs when the film plane is not parallel to lines that are required to be parallel in the photo:
https://en.wikipedia.org/wiki/Perspective_control

The keystone effect is a type of perspective distortion:
https://en.wikipedia.org/wiki/Keystone_effect

Perspective is much more than just a single station point and it's ludicrous to claim otherwise. Your loose and imprecise use of the term makes photographers that say "lens compression" seem like geniuses in comparison.

where did Tom go? could it be we can't see him due to different perspective? 🤣

That is funny Miljan :-)

Just for the record....Tom is cool and we actually agree with each other on some really important topics.

absolutely, just having fun... :D

The wide is the most natural and intimite to my eye. I think once the head gets blocky and the ears compress to the same plane as the rest of the face it starts to look distant and unnatural, at least to me. I am just more a fan of the contextual portrait look in general though. If I'm annihilating the background like that, I might as well have done a studio shoot. It would look less busy back there as a bonus too.