If you do any macro or close-up photography, you’ll likely come across the term “magnification.” Even outside of macro photography, most camera lenses include their maximum magnification in the list of specs.
So, what is magnification, and why is it so important in photography? This article covers everything you need to know.
Table of Contents
Magnification Definition
Magnification, also known as reproduction ratio, is a property of a camera lens which describes how closely you’ve focused. Specifically, magnification is the ratio between an object’s size when projected on a camera sensor versus its size in the real world. Magnification is usually written as a ratio, such as 1:2, which is said aloud as “one to two magnification.”
For example, say that you’re doing macro photography, and the object you’re photographing has a projection on your camera sensor which is 1 inch across. If the same object is 2 inches across in the real world, your magnification is 1:2. (It doesn’t matter what units of measurement you use; the important thing is the ratio between the object’s size on your camera sensor compared to its size in the real world.)
Magnification can also be written in decimal format. For example, 1:2 magnification could be written as 0.5x magnification (which is found simply by doing 1 ÷ 2). This is how magnification generally appears in a list of a lens’s specifications – 0.3x, 0.14x, 0.22x, and so on. Check out this table to see some examples of lenses and their magnifications:
| Lens | Magnification (Ratio) | Magnification (Decimal) |
|---|---|---|
| Nikon NIKKOR Z 70-200mm f/2.8 VR S | 1:5 | 0.2x |
| Canon RF 50mm f/1.8 STM | 1:4 | 0.25x |
| Sony FE 400mm f/2.8 GM OSS | 1:6.25 (4:25) | 0.16x |
| Fuji XF 200mm f/2 R LM OIS WR | 1:8.33.. (3:25) | 0.12x |
| Panasonic Lumix G 25mm f/1.7 ASPH | 1:7.14.. (7:50) | 0.14x |
| Pentax HD DA 35mm f/2.8 Macro LTD | 1:1 | 1x |
A special case is when the object is the same size in the real world as its projection on your camera sensor. This is 1:1 magnification, also known as 1x or “life size” magnification. It’s important because 1:1 magnification is considered the standard for macro photography, and most macro lenses at their closest focusing distance will be at 1:1 magnification.
The closer you focus, the larger your magnification will be. Macro lenses routinely go to about 1:1 magnification, although some (such as the Zeiss 100mm f/2 Macro) can only go to 1:2 magnification. A few specialty macro lenses can go beyond 1:1 magnification, such as the Laowa 100mm f/2.8, which can go to 2:1. A popular choice among macro photography enthusiasts is the Canon MP-E 65mm f/2.8, which can go all the way to 5:1 magnification! However, this lens can only shoot macro photos and cannot focus on anything distant from the lens; it’s confined to the focusing range from 1:1 to 5:1 magnification.
Most macro lenses tell you their current magnification in the same information window as your focusing distance. For example, on my Nikon 105mm f/2.8 macro, the magnification is visible in the window here:
The Effect of Camera Sensor Size
How does magnification relate to the size of your camera sensor? It’s not as straightforward as you may think.
On one hand, magnification doesn’t change at all because of your sensor size. It doesn’t even matter if you have a sensor; magnification is a property of the lens and the lens alone.
At the same time, you’ll notice that a macro lens can (seemingly) capture a more magnified view of your subject when you’re using a crop sensor camera. What gives?
Maybe a diagram will clear things up. Here’s how a sample subject (a coin in this example) looks at the same magnification on two different sensor sizes:
As you can see, the coin’s projection is physically the same size on both sensors. (If it looks larger to you on the aps-c sensor, that’s just an optical illusion; the pixel dimensions are the same.) So, it doesn’t matter what size sensor I put behind the lens – it can’t change the physical size of the projection. The magnification is identical in both cases.
What does change, however, is that the coin takes up a greater percentage of the smaller sensor. If you were to make a print of both of these photos and display them at the same size, obviously the coin would be larger on the photo from the aps-c sensor. So, even though the magnification hasn’t changed, the composition has.
If it helps, you can think about it like this: Shooting with a crop sensor is like cropping an image from a full-frame sensor. In the same way that cropping a photo doesn’t increase magnification, neither does using a crop sensor. But it does make the subject larger in your final image.
The takeaway is that small camera sensors can actually work great for this type of high-magnification macro photography. In fact, if they have smaller pixels than the full frame camera, they’re likely to be at an advantage.
For instance, a 24 megapixel APS-C camera is usually preferable to a 24 megapixel full-frame camera if you need as much detail as possible on a high magnification subject. On the other hand, a 45MP full-frame camera and a 20MP APS-C camera have almost exactly the same pixel density, so neither is preferable to the other for macro.
It’s similar to the situation with extreme telephoto photography. When your goal is simply to put the maximum number of pixels on a small or distant subject, a crop sensor with a small pixel pitch works very well.
That said, if you’re not at your lens’s maximum magnification (nor very close to it), large camera sensors still have the same benefits as always.
Why Magnification Matters
Unlike some camera settings like shutter speed or aperture, you don’t really need to be thinking constantly about your magnification if you want to get high quality photos. But that doesn’t mean it’s unimportant.
Magnification is important in two main contexts: buying a lens, and figuring out your depth of field.
The first one is straightforward. Now that you understand magnification, you can easily figure out whether a particular lens offers enough close focus capabilities for your needs. For example, you may realize that you need a 1:1 macro lens for what you’re photographing, and a lens that advertises itself as macro but only reaches 1:2 won’t be enough.
Alternatively, some lenses may not advertise themselves as macro lenses, even if they have pretty impressive close focusing capabilities. For example, the humble Nikon 18-55mm AF-P kit lens can reach to about 1:2.6 magnification (0.38x), and the Canon 24-70mm f/4 goes even further to 1:1.4 magnification (0.71x). That’s more than you’d get with many so-called “macro” lenses from other manufacturers! With either of these lenses, you could take close-up photos of larger subjects like flowers, lizards, dragonflies, and so on, without spending hundreds of dollars on a dedicated macro lens.
The Nikon 300mm f/4D lens is famous for its close-up abilities despite not technically being a “macro” lens.
The other context in which magnification matters is in figuring out your depth of field. No matter what lens you have, your depth of field is going to be very shallow at high magnifications, and it falls off dramatically once you’re at 1:1 magnification and greater.
This is because depth of field shrinks as you zoom in and focus closer. Because magnification can be thought of (and even expressed mathematically) as a combination of focal length and focusing distance, there’s no way around it: High magnifications have low depth of field.
If you know what magnification you’re at, you’ll have a good idea of the depth of field you can get. For example, I know that when I’m at 1:1 magnification, I need to use an aperture of at least f/16 in order to get enough depth of field, and maybe even f/22. By focusing a bit farther back – say, 1:2 magnification – it becomes possible to use f/8 or f/11 instead, for the same depth of field.
This is helpful knowledge to have on the fly if you don’t have time to chimp. It’s also nice to know beforehand how to deal with certain magnifications – such as using a flash at 1:1 because of those small apertures, or using focus stacking if you get to extreme magnifications like 4:1 or 5:1 to get back depth of field.
How to Increase Magnification
The only way to increase magnification without resorting to external accessories is to focus closer and closer (or buy a different lens).
If you don’t mind using accessories to go further, here are some things you can do to get more magnification than your lens natively allows:
- Extension tubes/bellows system. Extension tubes are glass-less tubes that go on the back of your camera lens to push it farther from your camera sensor and increase magnification. (Bellows systems do the same thing but are shaped like accordions.) These accessories are very popular for macro photography, and they can extend your magnification significantly. Extension tubes give you the biggest magnification boost if you’re using a wide angle lens. Don’t worry about using a macro lens; even something like an ordinary 35mm prime can get very high magnifications (about 0.5x to 1.2x) when paired with a 20mm or 36mm extension tube. Be sure that whatever extension tubes you get have electronic contacts meant for your camera brand. Otherwise, you’ll have no way of changing aperture with most modern macro lenses.
- Reverse lens technique: I’m not a big fan of this route because it’s much harder to control aperture (aside from some specialty reverse adapters for Canon), but reversing your lens – literally attaching it to your camera backwards – is another potential way to increase magnification. Particularly with a wide-angle or normal lens, this method can offer extremely high reproduction ratios such as 1:1, 3:1, or beyond. The wider your lens’s focal length, the more magnification you could get.
- Dual reverse lens technique: Interestingly, you can also re-use the reverse lens technique by attaching one lens, reversed, onto another’s front filter threads. Divide your lens’s focal length by the reversed lens’s focal length to get your new magnification. You can get extreme macro images this way (such as reversing a 20mm lens on a 100mm lens for 5x magnification). It’s a bit of an unwieldy setup and can introduce unwanted lens aberrations, but it’s fun to experiment with and certainly does work.
- Close-up filter. There are plenty of specialty close-up or macro filters that screw onto the front of your lens. They don’t always have the highest optical quality, but if you avoid the cheap ones, this is a good way to increase your magnification even without a macro lens. In contrast to an extension tube, close-up filters have a greater effect on longer lenses, and comparatively less of an effect on wide-angle and medium lenses.
- Teleconverter. If you have a teleconverter, that’s one of the easiest ways to increase magnification. Specifically, a teleconverter increases your magnification by the same factor that it increases your focal length. For example, a 2x teleconverter will double your magnification – meaning that a 1:1 macro lens will now be able to go to 2:1 or 2x magnification. The biggest issue with this method is cost; teleconverters tend to be more expensive than the other techniques on this list.
The best way to get high magnifications is still to use a macro lens, but hopefully this list gave you some good ideas on how to go beyond that. Personally, my favorite of these methods is to use a set of extension tubes combined with a 35mm or 50mm prime.
I used the Nikon 300mm f/4D in combination with a 1.4x teleconverter to increase my magnification for this photo.
Lenses with High Magnification
If you’re reading this article, chances are you want to find out how to get as much magnification as possible. If the tips above for getting high magnification with your existing lenses aren’t enough, it might be time to get a shiny new lens with even more magnification.
Luckily, every manufacturer has at least one dedicated macro lens, which you can get from B&H photo with the following links:
- Nikon Z: Nikon MC 105mm f/2.8 Macro
- Nikon F: Nikon AF-S VR 105mm f/2.8 Macro (discontinued, but you can still get it used here)
- Canon RF: Canon RF 100mm f/2.8 L Macro
- Canon EF: Canon EF 100mm f/2.8 L Macro
- Sony E: Sony FE 90mm f/2.8 OSS
- Fuji X: Fuji XF 80mm f/2.8 R LM
- Pentax K: Pentax D-FA 100mm f/2.8 Macro
- Micro 4/3rds: OM System 90mm f/3.5 IS Macro
All these lenses go to 1:1 magnification or more, and will likely provide enough magnification for almost any application.
Problems with High Magnification
High magnifications are a lot of fun to use, but it’s not always easy to get sharp photos once you go beyond a certain point. That’s because you’re not just magnifying your subject at these ultra-close focusing distances; you’re also magnifying things like camera shake and subject motion.
On top of that, because high magnifications have such a low depth of field, you’ll also need to be shooting at small aperture settings when you focus especially close. This means you’re in for some photos that are dark and blurry – not to mention out of focus, since focusing is also difficult when your depth of field may be just a few millimeters across!
If your subject is staying still, you can fix most of these issues by focus stacking from a tripod. Even if you don’t focus stack, simply using a tripod allows you to use longer exposures to negate the darkness of f/16 or f/22. It also makes focusing much easier.
However, if your subject is moving, or you’re shooting handheld, focus stacking is much harder, if not impossible. At that point, the best option is to use a flash while practicing your best close-up focusing technique.
These challenges aren’t easy to overcome, but it’s possible to do it with some effort, and that’s half of what makes macro photography so fun! When you do succeed at getting a sharp photo at extremely high magnifications, it’s very rewarding.
Conclusion
Hopefully this article answered your questions about magnification in photography. I’ve also introduced the challenges of getting sharp photos at high magnifications, which you can learn more about in our longer macro photography guide.
If you have any questions about magnification or macro photography, let me know in the comments section below!
Excellent article! So when compare a 70-200mm f2.8 lens at 100mm and a macro 100mm f2.8 lens, one has to compare at the each’s minimum distance, The 70-200mm f2.8 has min. focus distance at 70cm and the macro has the min distance at 26cm (my case). If you compare both at 70cm in distance from the subject, then the results (depth of field, bokeh) are same, right? But the 70-200 can never focus at 26mm. On the other hand, once move the 100mm macro to its min. at 26cmm, the depth of field is much narrower, that’s why one needs smaller aperture to increase the depth of field, and thus need better lighting. Some people suggest that bring a hand light with you. That’s also why a macro lens mostly at no brighter than f2.8 because you have to reduce it to maybe f5.6 at 26cm anyway. Am I right? I did not pay too much attention to Maximum Magnification until I read your article because I am considering buying a macro lens which is on sale (Canon RF 100mm f2.8). Again. thank you. I have learned a lot.
I just found this article when trying to understand the magnification offered by a non-macro lens. This 100mm full-frame lens. The manufacturer’s (Sony’s) blurb, complete with their colorful verbiage says:
“Because one of the main features of this lens is bokeh, it has been provided with a macro ring switch that extends the lens’s range into the macro region where bokeh can be used to great effect. The macro mode provides 1.87 ft (0.57 m) minimum focus with 0.25x maximum magnification, with no compromise in resolution performance.”
It is that ” 0.25x maximum magnification” I am trying to understand. I’ve got a pretty good reference for what 1:1 would be, as full frame based on the old 35mm film would be the size of a 35mm slide. I can picture four such rectangles forming a larger rectangle, (2×2)) or a total size 4x any one slide’s image. 4x sure sounds like 25%, but I am unsure that is the correct view. For all I know that 25% might be applied linearly, meaning I need to picture a 4×4 rectangle that covers 16 times the area of the sensor (or a slide image).
Excellent writing. Very easy to understand for almost everybody who has taken his hands on an interchangeable lens camera. It’s concise, and nice to read, thanks.
Loved this article, love such articles. Great work!
It seems to me that there is a trend to use long telelenses rather than macro lenses or adapters etc. for macro subjects like butterflies and damselflies. This has the advantage of not needing to come close with risk of disturbing the insect. There are some example pictures taken with a telelens in your article, however the magnification (that must be high) is not discussed. I’m using myself a 70-200 mm semi-macro lens at the long end, sometimes combined with an extension tube, but I wonder whether an even longer lens for flying insects would not be more useful. Extension tubes have the disadvantage of getting too close to your living subject.
Many dragonfly / butterfly photographers use longer lenses like a 4/300mm because of longer working distance and better background blur, especially for in-flight shots. However, this is more “close-up” than real “macro” with magnifications in the 1:10 to 1:2 or so range.
Longer lenses (especially from 400mm or so) have disadvantages too to like lower native magnification, more size/weight that makes tracking fast/erratic flying subjects more difficult. DOF can be so small that it can be impossible to find and focus on the subject before it is out of the frame again. Because of those limitations I prefer a 100-200mm lens for the fastest dragonflies. Longer lenses are nice though when the subject is hovering or gliding.
Many long zooms like my Canon 100-400II have IQ compromises when used near MFD and there are few long primes with high magnification, good closeup image quality and modest weight and cost. Most recent lenses are either very bright, heavy and expensive primes with relatively long MFD or dim, optically compromised (for closeups) zooms; some exceptions though like Nikon PF lenses.
Nice article Spencer. I particularly had an “aha!” moment when reading that magnification is a property of the lens’ projection, not the size of the sensor behind it.
Would you consider doing a similar article on viewfinder magnification? I can’t wrap my head around the magnification spec of “0.77x” (for example) of modern OVFs & EVFs.
Thanks!
Glad you found it useful, Brian! I would need to read up on the technical background behind those specifications before writing an article, but I would consider it if there’s interest. I know what you’re referring to, but I’ve only ever used that specification when comparing how large the viewfinder will seem, among cameras with the same sensor size.
Spencer, you say about close-up filters: “They don’t always have the highest optical quality, so it’s not my top recommendation.” I wonder if you have any experience with Raynox DCR-250. I’m quite happy with its image quality when coupled with my telephoto lens (Nikon AF-P Nikkor 70-300mm f/4.5-5.6E ED VR). Also, unlike some other macro techniques, it gives me the flexibility to change the magnification ratio by zooming in and out with the lens.
Marcin, that’s a good point. I was thinking back to my negative experiences with a really cheap one, but if you get a good close-up filter, you can get some high quality images. I haven’t used the Raynox, but from sample images I’m seeing online, it looks quite good. I don’t see any of the severe chromatic aberrations that plague some of the cheaper close-up filters. Using it on a zoom to get variable magnification is also a good plan.
I’ve corrected that part of the article to say “if you avoid the cheap ones, this is a good way to increase your magnification.” I think my prior wording was overly negative.
Thanks for an informative and, to me, unrealised aspect of focus. Does this relate to a situation were a large aperture (eg F5.6) has been used in a far ranging landscape shot, and yet (paradoxically to me) the shot is in focus from front to back? I am confused as to how this can be, because it seems to contradict the rule of smaller aperture = greater depth of field. I am sorry if this turns out to be off subject.
Navek, no worries, that’s a good question. Depth of field depends on more than just your aperture. There are also two other factors: focal length and focusing distance.
I’m not surprised that you’re seeing a lot of depth of field when you focus on something far away, even at a medium aperture like f/5.6. The farther you focus, the greater your depth of field becomes. So, you’re correct that it relates to this article, where I say that your depth of field gets very shallow at high magnifications/close focusing distances.
The other factor, focal length, works the same way. The further you zoom in, the less depth of field you’ll get. This is how wildlife photographers can get a shallow depth of field despite focusing far away and even using narrow apertures like f/11.
You may find Elizabeth’s article on depth of field useful: photographylife.com/what-…h-of-field