5 reasons to shoot prime lenses & a couple of reasons not to
Over the years I’ve had the pleasure of owning both prime & zoom lenses, with notable zooms including the Nikon Holy f/2.8 Trinity (14-24mm, 24-70mm & 70-200mm VR II) for F mount and the groundbreaking Sigma 18-35mm f/1.8.
However I have since sold off all zooms and confined myself to a collection of primes only. Haven’t ruled out getting some zooms again in the future, but for the time being, I’m staying the course.
Here are 5 reasons why one would prefer to shoot prime lenses over zooms. I didn’t even prepare 5 of them to begin with, but now I do have to come up with them. :-P
Before we begin: some terminology
A zoom lens covers multiple focal lengths, this one here starts at 12mm
Not everyone is accustomed to photography terminology, so in case the terms “prime” & “zoom” don’t ring a bell, here are some short definitions:
A prime lens is a lens with a fixed focal length, i.e. it doesn’t offer a range of available magnifications, it is limited to a singular value, e.g. 50mm or 85mm. As a result if also offers a singular field of view. One would generally refer to such a lens as, for instance, a “35mm prime” or “the 35” (in the case of a lens with a 35mm focal length). There is no way to change the size of your subject in your frame other than getting physically closer or further from it. This is called:
Zooming with your feet
Prime lenses are generally simpler to make because they have fewer moving parts, allowing them to incorporate less complicated optical formulas that lend themselves to larger aperture values and high sharpness levels in a smaller lens chassis. Aperture ratios of f/1.4 or even smaller (f/1.2, f/0.95 etc) are not unheard of for a prime lens. Primes historically came first, since they were the simpler design. In all likelihood, you’ve already shot a camera with a prime lens: your smartphone; the overwhelming majority of camera phones are prime lenses usually around the 28mm mark. There are prime lenses of all categories, focal-length wise, ultra wide angles, wide angles, normal, telephoto & super telephoto. The grand majority of macro lenses are also prime lenses. Prime lenses generally stay the same size throughout their usage, except in the case that they are externally focused lenses (as opposed to internal), because in that case they expand or contract as the focusing plane is changed.
A zoom lens, on the other hand, is a lens that covers a range of focal lengths, starting from the “wide end” up until the “tele end”. A zoom lens is referenced by specifying the start & end of its focal length range, i.e. a 24-70mm zoom is 24mm on the wide end and 70mm on the tele end. You’ll also hear people simply referring to such a lens as a 24-70 (“24-to-70”). The photographer can change the focal length of the lens usually by rotating a ring on the lens chassis, the zoom ring, or in the case of compact cameras & camcorders, by using an analogue switch marked W/T (wide-tele). A zoom lens is flexible in that it can offer a number of different framing options for the same subject-to-camera distance. To change the subject size in the frame one need not physically move, they can expand the field of view by “zooming out” or get a tighter framing by “zooming in”. This is very convenient but can also make one less inclined to explore different perspectives that can only be achieved by physically moving closer to or further from the subject, and therefore often dismissed as “laziness”.
For applications where having multiple focal lengths available in the same lens is more time-effective (e.g. live events) or space-effective (e.g. travelling) than switching lenses, zooms come in very handy. Most kit lenses, i.e. lenses that come bundled with cameras as a single package, are zoom lenses, because for beginner photographers usually versatility is of the essence. The size of a zoom lens will generally fluctuate as its is zoomed, although there exist also internally zooming lenses, where the elements will move inside the chassis and not cause any extension or contraction of the outer lens body. Due to the complexity of having to accommodate both different focal lengths (zooming) and different focusing distances (focusing), optical formulas for zooms are generally more complicated, leading to bigger physical lens sizes, with potential for smaller maximum apertures and less peak sharpness compared to a comparable prime. The maximum apertures that have been achieved for zooms are, at the time of writing, featured by the Sigma 24-35mm f/2 and Canon 28-70mm f/2 for full frame, the aforementioned Sigma 18-35 f/1.8 for APS-C and Panasonic Leica 10-25mm f/1.7 for Micro Four Thirds (with an upcoming 25-50mm f/1.7). Professional zooms are predominantly in the f/2.8 area, whereas entry-level consumer zooms will range in the f/3.5-f.5.6 or even f/6.3 area.
OK, so those weren’t exactly short definitions, but I digress. On to the list.
1. Creative limitations boost creativity
A 55mm trip to Thessaloniki (Salonica)
The term “creative limitation” sounds a bit counterproductive, but limiting the amount of variables one needs to keep in mind when taking a picture can actually be liberating & help free up energy better spent in other aspects of photography such as exposure, composition, focus, etc. Other examples of creative restrictions one can apply to further boost their creativity can be: shooting film (which makes every shot count), shooting in black & white, using natural light only, shooting wide open only (or only at f/8,) shooting strictly hand-held or strictly on a tripod and so on and so forth. Any variable you get rid of is one less thing to worry about in the field and one less decision you need to make.
When going on a trip, I often choose to take a single prime with me, effectively making it a 50mm trip, a 105mm trip etc. On said trip I cannot wish I had another prime or a zoom with me (well I can, but it doesn’t change my situation), I have to make do with the singular focal length I have in my camera bag. Consequently, focal length selection is one decision I need not make at that point in time. This also helps me become even more familiar with the field of view I have access to and encourages me to work around the restrictions this focal length presents in capturing the imagery I want. At the end of the day, this self-imposed “handicap” can help make one a better photographer.
2. Being more conscious about your focal length choices
Have you ever heard of an image taken with a 122mm lens? With a 39mm lens? Yeah, me neither. One can probably remember they shot a pic with a 24-70mm mounted or even if it was at the wide, mid or tele end of that lens, but one would have a really hard time remembering the exact focal length setting unless they looked at the EXIF data. Now, a follow up question would be: does it matter? Well, yes & no.
On the one hand, at the end of the day, only the actual image matters and the viewer could probably not care less about the focal length, aperture, shutter speed & ISO it was shot at. And this is good to bear in mind to avoid obsessing about the technical stuff. While photography schools do teach heaps of technical details, the end goal is for the technical aspects to become second nature for the students, so that they can focus on taking (and making) great images that intrigue the viewer.
On the other hand, after a few outings with single prime, one becomes very conscious about what a 24mm, 28mm, 35mm, 50mm, 85mm, 105mm, 135mm, 200mm or other focal length can do for them. These focal lengths become a common language you can use to communicate with other photographers. Many photographers are well known to have a particular favourite focal length, e.g. street photographers often swear by the 28mm. Choosing the wrong focal length (or focal length range) to have on you at the time of a shoot can make or break your ability to take the shot you want. While having too wide a lens can be partially salvaged by cropping in post (though can kiss some resolution & depth of field goodbye), having too tele a lens with you can render it totally impossible to capture a wide scene (unless you resort to multiple shots & stitching which is impractical for many subject types).
Thus, if not for viewers, focal length is definitely something photographers need to be conscious about, and primes, featuring a singular focal length, offer a sure-fire way to get accustomed to what a particular field of view can do for you.
3. Access to wider apertures, lighter lens bodies & potentially higher sharpness levels
7artisans 35mm f/0.95 prime lens - don’t expect to see an f/0.95 zoom any time soon
The simpler optical formulas of primes allow for the creation of lenses with bigger maximum apertures while maintaining a pretty compact size. While the fastest consumer-available prime clocks in at f/0.85, the fastest zoom achievable only starts at double that (f/1.7). An f/1.4 zoom, even a wide angle one with a small zoom range, would be impractically large, although the large mounts and small flange distances of the Nikon Z mount & Canon RF mount may make this easier in the future. For the time being, if f/1.4 or faster apertures are desired, primes are the only way to go. This is especially important for portraiture, where maximum separation of the subject from the background is often desired and for event photography in dimly lit conditions (e.g. churches), where a fast prime may allow one to shoot at 1-2 stops lower ISO than a pro f/2.8 zoom, which might yield considerably cleaner images to work with.
From APS-C upwards (Micro Four Thirds still achieves pretty compact pro zooms due to its small sensor size), the size of all f/2.8 pro zooms is pretty unwieldy, at least for prolonged use. You wouldn’t want to lug around a 70-200mm f/2.8 on a casual trip. The Canon 28-70mm f/2, which offers a class leading f/2 maximum aperture for full frame, is one behemoth of a lens. Additionally, wide aperture zooms also draw a lot of attention due to their size & appearance, making it difficult to be discreet, should that be a concern. On the other hand, with the exception of Sigma & Tamron which of late have leaned towards designing highly optically corrected primes of gargantuan proportions (though still smaller than most zooms), a 50mm f/1.4 or f/1.8 is usually perfectly manageable in size, putting way less strain on the photographer’s arms and hands, while unlocking depth of field thinner than what is achievable by all but the fastest of zooms. My Nikon 180mm f/2.8, one of my favourite lenses, is both smaller than even 70-200 f/4 zooms (let alone f/2.8), much cheaper than any full frame pro zoom and half the weight. It does lose out on a number of features, such as image stabilization and access to any focal length other than 180mm, but if one is interested in the tele end of the 70-200mm range, I find that its benefits more than outweigh its shortcomings.
Last but not least, while the jury is out on whether primes are de facto sharper than zooms, empirical evidence suggests that this may be the case. Even fully corrected primes with a high element count (e.g. 13+) tend to have fewer optical elements than pro zooms, which can reach an element count in the low 20s (22-23). Experience shows that the passing of light through an increasing number of elements does seem to be a lossy process. It is not uncommon for an entry- or mid-level 50mm f/1.8 prime to outclass a premium 24-70mm f/2.8 in sharpness at given apertures, making the prime a pretty amazing value proposition if you’re going to be shooting around the 50mm mark anyway. Whether true of placebo, in the photography community zoom lenses that break this rule are often called prime-like, which reinforces the notion that the way primes render does have a certain “je ne sais quoi” about it that sets it apart from zooms. Such zooms with prime-like qualities include the Nikon 80-200mm f/2.8 AF-D and the Fujifilm 16-55mm f/2.8, among others.
4. Avoiding zoom lens deficiencies
Primes are immune to a number of issues that plague zoom lenses, or at least, affect zooms more heavily.
Externally zooming lenses (i.e. those that expand or contract as one moves trough the zoom range) suck in more air. This can cause more dust particles to enter the camera body and possibly settle on the image sensor. This in turn can make dust spots appear on the images captured, especially if the lens is stopped down significantly (f/8, f/11 or smaller). Externally focusing primes also allow more dust particles to enter the lens & potentially the camera, but the range of expansion / contraction is far more limited compared to zooms.
Lenses made for DSLRs usually need to be calibrated to the body because the Phase Detection Auto-Focus (PDAF) sensors on a DSLR camera are not located on the same image plane as the sensor. A fraction of the incoming light is actually diverted to a separate sensor array which gauges the quality of focus and instructs the camera to adjust the lens focusing distance so that the area contained by the selected focus point becomes acceptably sharp. To compensate for the error margin introduced by this arrangement, many upper-tier consumer & pro-level DSLR bodies offer the capability to make micro-adjustments to the AF sensor operation so that front- or back-focusing issues are mitigated. Zooms are at a disadvantage here because they may display a different focusing behaviour at different focal lengths. Some manufacturers allow different adjustment settings for each end of the focusing range (e.g. Canon) whereas others (e.g. Nikon) force the photographer to enter a singular value, which will need to be the best compromise between the wide & tele end (ideally biased towards the tele end where the depth of field will be thinner and accuracy of correction is more important). Primes are less impacted by the limitation of single adjustment value since their focal length remains constant. Note that adjustment values are also impacted by focusing distance though and some lens manufacturers like Sigma allow calibrating the lens for far, medium & close distances as well.
Many externally zooming lenses are also susceptible to a phenomenon called zoom creep. This refers to the tendency some zooms have to automatically slide to a different focal length when not held parallel to the ground. This is a result of gravity combined with a zooming mechanism that doesn’t have sufficient resistance to keep the lens elements in place when the lens is titled to either side. Consequently, if one puts a camera body with a zoom lens attached down and picks it up later, it may or may not be at the same focal length setting they left it on depending on whether the lens was tilted upwards or downwards. This can potentially lead to some frustration because the photographer may need to recompose for subsequent captures. Some manufacturers include a zoom lock on their lenses to help solve this problem. Internally zooming lenses & primes are not affected by this phenomenon, though that is not to say that primes always stay at the same focal length.
Surprisingly, primes (as well as zooms) can suffer from another imperfection called focus breathing. Lenses that display focus breathing do not maintain the same effective focal length throughout their focusing range. E.g. a 50mm lens can be around 52mm at minimum focus distance, whereas it can turn into a 47mm when focused at infinity. So, in a sense, primes are zooms as well, since they don’t actually maintain a constant focal length. An exception to this are cinema lenses which are engineered to higher standards so as to keep a constant focal length throughout their focus range. This is to facilitate better focus pulls without the risk of confusing the spectator by a change in magnification.
5. ?
OK, I was hard-pressed to find a fifth reason but here goes:
Primes give you access to an ecosystem that is orders of magnitude bigger that that of zooms.
Wanna see my collection of vintage zooms?
— No one, ever
Vintage primes, gotta catch ’em all
If you are a casual shooter, this may not impact you at all, but if you are planning to become a lens collector, you will be spoilt for choice with the plethora of 2nd hand primes available online or at physical marketplaces.
Highly collectable zooms can literally be counted on fingers of one hand. A few of the known ones are: the Nikon 28-70mm f/2.8, 80-200mm f/2.8, 28-105mm, 70-210mm f/4 and a couple more. On the prime camp, there are probably dozens very desirable primes at the 50mm focal length alone.
The advent of mirrorless cameras has made adapting vintage lenses more popular than ever. The vast majority of adapted lenses can be focused only manually, thus primes are again simpler to operate since they need not (and cannot) be zoomed. They also have fewer mechanical parts, making them less likely to break down.
6. Profit!
If you’re a South Park aficionado, you have a special place in my heart.
And some reasons you might want to avoid a prime
Or rather, some use cases where a prime may not be your best bet.
Unless you’re really confident that you can work around the limitations of a certain focal length, a zoom lens, especially the so-called travel / super zooms which span an enormous focal range, will be a more more flexible proposition for your casual & travel photography. A stabilized 24-200mm equivalent lens such as the Olympus 12-100mm f/4 IS allows one to capture expansive architecture shots on the wide end while also enabling zooming to the far away mountain ridge of the picturesque city you’re visiting. If you only brought a 35mm prime with you, tough luck trying to isolate those mountains without including half of the town in the foreground as well. Especially if it’s a once in a lifetime endeavour, a prime might cost you shots that you’ll end up kicking yourself for. You could take multiple primes with you, but on a leisure trip, can you really be bothered to change lenses?
Like switching from a rifle to a sidearm is way faster than reloading, zooming or switching to a second body is way faster than mounting a different prime lens to get the desirable field of view. Multiple bodies with different primes mounted is a legitimate practice, but increases the amount of gear one needs to carry to an event and keep an eye on to prevent theft when left unattended. Changing lenses takes time and choosing to do so at a poorly timed moment may cost you a shot that you will not get another chance of taking. Imagine missing the newly-weds’ first kiss or the moment students throw their graduation caps in the air. You’ll have a hard time justifying why you were given the job in the first place. Limiting oneself to primes makes good planning all the more critical and a zoom can be a reasonable alternative to alleviate the stress involved. Note that a lens change also gives the opportunity for dust particles to creep into your lens body, especially with mirrorless bodies where there is no mirror to stop some dust from ending up on the sensor. Finally, a lens change in dim light or in the dark is no easy feat; you may end up needing to bring a flashlight so that you can see what you are doing (which may or may not be disruptive for the event at hand) plus juggling multiple optics increases the chance you might drop one with dire consequences.
Changing lenses can be a nuisance
Money-wise, primes aren’t all that and a bag of chips. While they may be more cost effective on a per item basis, you may need 5-6 primes to cover the popular focal lengths you’d like to have in your arsenal. Now if you need only a couple of primes, that’s great. It is often said that:
a 35mm & a 85mm is all you need
…and I have found that to be quite accurate in the field. However, if you wish to have access to the whole range, the cost of primes quickly adds up to the point that 2 zooms or a super-zoom make more sense financially.
While primes open many creativity options with their usually large apertures, some creative effects are physically impossible with a prime. A zoom lens allows for a technique called zoom burst, which translates to zooming while dragging the shutter (i.e. shooting at a slow shutter speed) which can create quite a dramatic look, especially for action shots. A zoom lens can obviously also zoom in video, while with primes only digital zoom is available, at the expense of resolution.
Zoom burst - By Jonathan Miske from United States - Seattle Starburst, CC BY-SA 2.0, https://commons.wikimedia.org/w/index.php?curid=68773113
As a final note, primes are usually more likely to be appreciated by the connoisseur and I don’t mean that in a snobbish sense. For those who just want a camera to take pictures of their kids, the singular field of view & the razor thin depth of field that primes ofter feature when shot wide open can be more of a hindrance to the user, than a benefit. On the other hand, entry level zooms with their slow apertures make it very hard to blur the background out, should that be desired, but this usually becomes a concern once a photographer is transitioning from simply taking snapshots to delving deeper into photography. For those who won’t cross this line, the kit zoom may be all the lens they ever need.
Epilogue
While I’m a primes-kind-of-guy at the time of writing, there has been no shortage of times where I wished I had brought a zoom instead.
I hope the aforementioned points can help you make an informed decision on whether a prime or zoom lens would be the best fit for you, or at the very least, that it was good content ™.
I need to think of some slogan to end blog posts with so here’s what I’ve come up with in my current stoic / nihilistic frame of mind:
We’re all gonna die, no one cares what gear you are using, so just go out & take pics that resonate with you.
Cheers!