How to get sharp, in-focus pictures?

This week, I’m continuing with a new tips article! After sharing plenty of tips and techniques in different areas, we’re now tackling a topic that comes up all the time: getting sharp, in-focus pictures! One of the first things we often hope for when moving to a more advanced camera, like a DSLR or a mirrorless model, is to see more detail in our photos, especially because these cameras have larger sensors than smartphones, compact cameras, and traditional bridge cameras. Still, if these cameras are considered advanced, it is also because they require a bit of know-how. So don’t assume that buying this kind of camera is enough to suddenly get perfect images! The level of your camera matters far less than how well you know how to use it.

First, it is important to distinguish between two things: being in focus and being sharp. With these large-sensor cameras, you can create those famous foreground and background blurs, also known as “bokeh”, which is one of the reasons we find them so appealing. The area where the image is sharp, between those blurred zones, is the focus area. The size of this focus area is called depth of field. So, it is not directly linked to the level of detail, although the contrast between focus and blur can heighten that impression. In fact, a sharp area will look even sharper when it sits between blurred areas! Sharpness, on the other hand, really refers to the level of detail in the elements located within that in-focus area.

So, the first thing to think about is the focus area, which is determined by focusing. With short focal length lenses, especially at small apertures, this area will be very large. With slightly longer, or even very long, focal lengths and large apertures, however, the focus area is often very narrow. As a result, the slightest shift can make the photo look blurry, when in reality the focus area simply is not where you wanted it to be. Another setting that can affect the sharpness of your image, whether across the whole frame or only on the subject, is exposure time. You have probably heard of camera shake and subject blur. The first comes from the photographer’s movements (so, yours), while the second comes from the subject’s movements (which, of course, do not exist if the subject is completely still).

When it comes to sharpness itself, other elements come into play, mainly the sensor and the lens. For example, beyond making the focus area larger or smaller, aperture does not always produce the same level of detail at every value or across the whole image. The range and type of lens also matter. ISO sensitivity has an impact too, because the higher it goes, the more digital noise appears. Finally, in a more minor but still possible way, the cleanliness—or rather the lack of cleanliness—of the lens and sensor can also affect image sharpness. I can tell you, for example, about a lens that was supposed to deliver a very high level of detail. I bought it secondhand, and it arrived with a filter screwed on so tightly that I couldn’t remove it right away. During my first tests, the details looked particularly soft, and I started to think the lens’s reputation might be exaggerated. That was until I finally managed to remove the filter, which wasn’t exactly a cheap one, and the results were, quite literally, clearly different.

So here are my tips to help you get the best possible focus and sharpness, whatever your sensor and lens. Keep in mind that I’m talking about getting the most out of your own camera in particular. So don’t be surprised if, when comparing an image shot with a Micro Four Thirds camera and an entry-level lens to one taken with a full-frame camera and a high-end lens, you don’t reach the same maximum level of detail.

You will often hear that sensor size changes depth of field, and that the larger the sensor, the shallower the depth of field. In reality, that is not quite right: the sensor itself does not change depth of field. To get identical framing, under the same conditions as with a smaller sensor and without moving, you can choose a shorter focal length. For example, if you want a composition equivalent to 35mm on a full-frame camera, you would use 23mm on APS-C or 17mm on mFT. By the way, we also have an article about focal length on the blog. Now, a shorter focal length, such as 12 or 16mm, used at the same aperture, gives a greater depth of field (so, less blur). The advantage, when we are looking for a high level of detail, is that focusing errors become less likely.

Conversely, with longer focal lengths such as 85 or 200mm, this depth of field becomes shallower, and the risk of focus shift increases. In other words, the more you use long focal lengths and tight framing, the shallower the depth of field becomes, and the greater the risk of missing focus on your subject. This is true regardless of sensor size, even if it happens less easily with smaller sensors. But we are talking here about mirrorless cameras and DSLRs with at least Micro Four Thirds sensors, which are already large enough to create fairly shallow depths of field quite easily.

As mentioned above, your framing will require a certain distance from the subject depending on the focal length you use. Here again, the tighter you frame, the shallower the depth of field becomes, either because you move closer to the subject or because you increase the focal length. Even with short focal lengths or small apertures, you can get very shallow depths of field simply because of your distance from the subject.

For example, wildlife photographers often use lenses such as 150-600mm f/5-6.3 zooms, which do not have especially large maximum apertures, and yet they can still produce sharp wildlife images with very blurry backgrounds. A long focal length, combined with the fact that they get as close as possible to the animals to frame them as tightly as they can, helps greatly reduce depth of field (and therefore create those lovely blurred backgrounds). You can do the same with a very short focal length by getting very close to the subject. Think of the field of view as a cone in front of you, and imagine a colored area representing the depth of field around the subject. Then imagine how that area would change if you moved closer.

As for the aperture of the diaphragm, it also affects the focus area. The wider it is, such as f/2.8 or f/1.4, the more depth of field is reduced at the same distance and focal length. Conversely, the smaller the aperture (such as f/5.6 or f/11), the greater the depth of field. You will often hear portrait photographers warn you about this. With large sensors and wide apertures, you can sometimes have such a shallow depth of field that it does not include the whole person, limiting sharpness to the face while the back of the head, the hair (if there is any—let’s not forget bald people!), or even the tip of the nose falls into blur. If the person is seen from the side, you may even notice a difference between the eye that is in focus and the other one.

As we saw above in the section on focal length and distance, the shorter the focal length and the farther away the subject, the greater the depth of field. This means that with short focal lengths and a distant subject, the focus area will often be very large, even with a wide aperture. On the other hand, with long focal lengths and a close subject, it will be much smaller, even with a small aperture. You will therefore need to be more careful in the second case than in the first, which may seem paradoxical since, most of the time, we recommend stopping down in landscape photography even though we often use very short focal lengths, and opening the aperture as much as possible in wildlife photography because we usually have less light than in landscape photography and fewer ways to compensate for it (for example, a tripod in wildlife photography lets your arms rest, but it does not stabilize the animal). Still with me?

All these concepts matter because they come into play when you focus on the subject. Depending on the result you want, especially if you want to emphasize blurred foregrounds and backgrounds, you will first need to choose your framing based on your focal length and distance from the subject. This will largely determine the size of your focus area. Then, you will need to choose your aperture and, finally, tell the camera where to focus (if you are using autofocus), or locate the subject yourself in the image if you prefer to focus manually.

Precision then becomes crucial, because the shallower this focus area is, the more movement will affect the image. As a quick aside, we do not have this issue in the same way on mirrorless cameras, but if you use a DSLR, you should know that phase-detection autofocus through the optical viewfinder is very fast, but it can also be imprecise, and it is not uncommon for it to cause focus shifts. In fact, manufacturers have even included an option on most of their cameras to correct these shifts, more or less effectively. Sigma and Tamron have gone even further by offering USB consoles that allow you to correct them more precisely. You can find plenty of tutorials online showing you the procedure to follow to check your camera. This is something every DSLR user should do whenever they buy a new lens. With this kind of autofocus, it is unrealistic to think manufacturers can produce perfectly calibrated lenses every single time.

When using autofocus, it is therefore essential to choose the right mode: single or continuous, with tracking on a single AF point, a group of AF points, or all the AF points on your camera. Keep in mind that the more AF points you use, the more precise the system can be, but the slower it may become. You can miss focus just as easily with many accurate AF points that are not fast enough to follow the subject as you can with fewer, faster AF points that are not accurate enough. Obviously, the more high-end the camera, the more likely it is to be both fast and accurate. Still, don’t convince yourself that you absolutely need to buy a €5,000 camera. Most cameras, even entry-level ones, have autofocus systems that are good enough for most situations, as long as you choose the right mode.

Personally, I would advise you to use continuous mode, especially with a very shallow depth of field. Even the slightest movement on your part can make you miss focus, even if the subject is still. It is not uncommon to lean slightly forward or backward between the moment you focus and the moment you take the shot. For stationary subjects with a large depth of field, single mode will often be enough and will speed up focusing a little. Of course, if you are focusing manually, you have several techniques available. For example, hyperfocal focusing allows you to maximize sharpness from the closest possible distance to infinity. Focus peaking highlights the sharp area on your screen. But in the end, if you miss focus, you won’t be able to blame the camera quite as easily, darn it!

Now that you have chosen the right camera settings so the focus area sits where you want it and covers the area you need, we can take a closer look at the level of detail within that area—in other words, sharpness. The first element involved is the lens, which sends light to your sensor through a set of optical elements. Of course, the more precisely these elements transmit light, the better the details will be. As is often the case, a higher price usually means better quality, because the best lenses, made with the most advanced coatings and treatments, cost more to manufacture and therefore more to sell.

However, things are never quite that simple. Lenses from “manufacturer” brands such as Canon, Nikon, or Sony also cost more because they carry those brand names. And it is not uncommon to find Sigma, Tamron, Tokina, or other lenses that produce results that are just as good, or even better, for much less money. Nikon’s 35mm f/1.4G, for example, is generally less good than the Sigma Art, and even less good than the more recent Tamron, while being the most expensive of the three. Within these brands, we even find lower-end lenses that perform almost as well as the high-end versions, such as Nikon’s 35mm f/1.8G compared with the f/1.4G, or Canon’s 35mm f/2 IS compared with the 35mm f/1.4L. The generation of the lens can also make a difference. For example, Nikon’s 24mm f/1.4G, which is supposedly more high-end than the f/1.8G, is ultimately not as good and was released much earlier, just like Canon’s 85mm f/1.2L compared with the more recently released 85mm f/1.4L.

And indeed, things are never really simple, because with a few exceptions, most lenses show differences in sharpness depending on the aperture, and for zooms, sometimes depending on the focal length too. On high-end lenses, manufacturers do their best to ensure strong optical quality from the widest aperture and to limit differences between apertures, but they rarely eliminate them completely. This is even more obvious on lower-end lenses, where other priorities come first (like reducing costs, really—no need to look much further! ahah). Whether primes or zooms, most lenses are less sharp at wider apertures. And when it comes to zooms, many are weaker at the extreme focal lengths (24 and 105mm on a 24-105, for example). But, one last time, nothing is ever simple, and some zooms may perform better at the ends than in the middle of the zoom range. So you will need to rely on tests, or even test your own lens, to know exactly where you stand.

One last little thorn in our side: sharpness is not always the same across the whole image! Usually, the edges lag behind the center, but once again, testing is useful because there can be surprises, such as edges that are as good as the center while the area between them is weaker, for example (don’t ask me why, but it does happen, although it is quite rare). Also, even when sharpness improves as you stop down, it does not necessarily improve evenly. It is not uncommon for the center to improve faster than the edges, or, conversely, when the center is already very sharp wide open, for only the edges to improve. As a general rule, lenses deliver their best sharpness at medium apertures: around f/4 for lenses that open to f/2 or wider, around f/5.6 for lenses that open to f/2.8, and around f/8 for lenses that open less widely. Of course, this is not an absolute truth, and you will need to test your own lenses to be sure.

Finally, don’t think you can simply stop down your diaphragm as far as possible to solve the problem, especially on lenses that close to f/22 or f/32. At these apertures, a phenomenon called diffraction appears and affects detail more and more strongly as you stop down. And the smaller your sensor is, the earlier diffraction becomes visible. So, on a full-frame camera, if it appears around f/16, it will start affecting the image around f/11 on APS-C and around f/8 on mFT. If you extend this principle to compact cameras with 1″ sensors or to smartphones, it will happen even earlier. So don’t be too impressed by a bridge camera like the Panasonic FZ200 with its 25-600mm f/2.8 lens, because with its 1/2.3″ sensor, diffraction is almost already at work wide open and will quickly get worse as you stop down!

The values above should not be taken too literally; they are valid when you are using a resolution of around 20MP. But as always in photography, the larger the enlargement, the more visible the flaws, and vice versa. So, if your sensor or the medium on which you display your images only uses 8MP, the tolerance is greater, and diffraction will become visible less quickly. On the other hand, if you have, for example, a 60MP full-frame sensor and you zoom in to 100%, you will already see the effects of diffraction at f/8. Remember: the smaller your sensor is, the more important it is to avoid stopping down too much!

Photography is a moment fixed on a light-sensitive medium, so the camera needs to know how much time it has to capture the light sent by the scene through the lens. If you have ever held a camera, you have probably seen numbers such as 1/1000, 1/250, 1/10, 2″… Again, if you are not very familiar with this concept, you will find an article on shutter speed on our website—we really do bend over backward for you! To take a simple example, move your hand quickly in front of you and you will notice that the faster it moves, the harder it is to distinguish the details. If you take a photo of your hand with a long exposure time (for example, 1 second), it will have time to travel a certain distance during that second, and your camera will record that movement. This is called subject blur, with your hand being the subject. To freeze it, you will need to find a short enough exposure time, and the faster your hand moves, the shorter that time must be, obviously. Many beginners get caught out by subject blur because they do not yet know the difference between this kind of blur and a lack of sharpness. Just remember that if the moving subject is blurred while the elements around it in the focus area are sharp and not moving, you are probably dealing with subject blur.

Another type of blur related to shutter speed is camera shake, which is also caused by movement, but this time, it’s yours! When you hold your camera by hand, even if you think you are very steady and have nerves of steel, you always move slightly, and these movements can affect the final image. The “rule” you will often see mentioned everywhere is the 1/focal length rule. Assuming you are shooting handheld without any stabilization (neither in the sensor nor in the lens), if you are using a 50mm lens, you should use an exposure time of 1/50 second or faster to avoid camera shake. This rule applies to all sensor formats, but it needs to be adapted because it originally refers to full-frame format. With a smaller sensor, you need at least to apply the famous “crop factor”; for example, APS-C has a diagonal about 1.5x smaller than full frame. You therefore need to multiply the focal length by 1.5. In our 50mm example, you would need to use at least 1/75 second. With mFT, you need to multiply by 2. For other formats, I invite you to look up their diagonal and compare it with full frame. I would even advise taking a safety margin with more pixel-dense full-frame sensors or smaller sensors: multiply by 2 for APS-C and 3 for mFT, for example.

If you have stabilization in the lens, in the sensor, or both, the rule still applies, but stabilization will allow you to use a slightly longer exposure time depending on how effective it is. For example, a stabilized 100mm lens, or a 100mm lens mounted on a stabilized sensor, will be able to handle exposure times longer than 1/100 second. If stabilization gives you a 2-stop gain, you can divide the shutter speed by 4, or use a shutter speed as slow as 1/100 × 4 = 1/25 second. For this reason, cameras with stabilized sensors, such as many recent Panasonic and Olympus cameras, or newer Sony and Nikon full-frame mirrorless models, have an advantage because sensor stabilization works even if the lens itself is not stabilized. This is especially useful with long focal lengths. If you have understood this rule, the longer the focal length, the shorter the exposure time needs to be, which often requires raising the ISO. Anyway, we will come back to that point later. This is why telephoto lenses are more often stabilized than wide-angle lenses, and why stabilization is also so useful in video, since your movements are continuously visible.

You will often need to worry first about the subject’s movement if the subject is moving, because unless you are using a long focal length, the exposure time needed to freeze a subject will generally be shorter than the one needed to avoid camera shake. For still subjects, on the other hand, it is better to focus on your own movements. In both cases, there are solutions to reduce or even completely avoid these types of blur, such as a monopod, a tripod, or a flash. A monopod, for example, can help reduce the risk of camera shake, much like stabilization, even if its effect remains limited. With a tripod, you will be able to use the exposure time of your choice, but remember that it does not reduce subject movement, just like a monopod or stabilization. For the subject, as long as it is not too far from you, flash can be very effective because it freezes action at a different exposure time from the one set on the camera.

After aperture and shutter speed, only one setting was missing to complete the exposure triangle in photography, and here it is: sensitivity. Digital technology has given us a lot of flexibility with this setting, because in the film days, rolls of film were limited to a single sensitivity—even if you could “push” them a little, though not too much without seriously degrading the image. So, to change sensitivity, you had to change film. Today, we can go from ISO 100 to 128,000 with just a few turns of a dial, or even let the camera do it automatically in a thousandth of a second. Thanks to this setting, we make the sensor more sensitive to light, although in reality it is only an electrical amplification of the signal—but I’ll spare you the technical details.

However, this amplification is not without drawbacks (that would be far too easy!). The higher you go in ISO, the more you get what is called “digital noise,” which appears as colored dots randomly distributed across the image. Processing algorithms can reduce this noise. The software analyzes it and tries to make it disappear, but this leads to smoothing of the details and to what some people call “grain.” That term should not really apply to digital images, though. In the days of film, images were made up of silver grains, hence the term “silver,” but in digital, this “grain” is not even noise itself; it is a consequence of noise reduction.

So, the higher you raise the ISO, the more the detail in your images will be affected. Ideally, if you want as much detail as possible in your images, you should stay at the lowest ISO setting. Obviously, that will be difficult in many conditions, if not impossible. So you will need to use all the techniques we have seen before: a flash, a tripod, a wide aperture… The best option, of course, is to shoot in the brightest conditions possible, but I know it can be difficult to summon the Sun God in the middle of the night (well, you can still try, but I’m not sure you’ll get an answer).

“But what vibrations?” you may ask… I am not talking about the good vibrations from the song, obviously. And yes, despite all the precautions you will have taken by following the advice in this article, there is still a way to increase your chances of getting even more detailed images. In a camera, there are often many moving mechanical parts, such as the shutter or the mirror, and when they move, they make the camera vibrate slightly and can add micro-blur. There is also the micro-movement caused by those things you have at the ends of your hands: yes, I’m talking about your fingers, which can add micro-shake simply by pressing the shutter release, even when you use a tripod!

Don’t get paranoid either! If you follow all these tips, you will already get very detailed images, whatever your camera. But if you want to go even further in your search for the finest details, there are a few other little tricks, such as using the self-timer or a remote control so you don’t have to press on the camera with your big hands full of fingers, haha! On most DSLRs, you will find an Mup mode, meaning “mirror up,” which raises the mirror for a set period before the sensor starts recording light, so you do not suffer from the vibrations caused when it lifts and closes. On some cameras, you can also choose between a mechanical and an electronic shutter. The electronic shutter does not cause vibrations, but it can create other unwanted effects, especially on large sensors, although this is becoming less and less of an issue.

When you are starting out in photography, all these things can feel a bit obscure, and you tend to blame your gear, especially when it gives you images that do not seem any better than the ones you can take with your smartphone or your old camera from the 2000s. How many times have I heard people complain about the detail of their 50mm f/1.8 on an APS-C DSLR, only to realize that their photos were taken at 1/30 second? And, to be honest, how many times did I complain about the same thing myself when I was starting out?

So, you should know that cameras and lenses sold today are capable of producing very detailed, even excellent images, as long as you know how to use them properly. Before buying a new lens because the one you have seems to lack detail, start by following all these tips, and most of the time, you will suddenly see that it can produce very sharp images. So, learn to master your camera and get the best out of it! You will realize that in most cases, it will do what you expect it to do, and the results will be further improved through image processing, especially sharpening. But that is another side of photography (processing and editing) that deserves one, or even several, other articles (be patient, they are on their way!).

In order of importance, so to speak, here are the steps to follow to get the best image sharpness:

• Set your focus,
• Choose your shutter speed (think about camera shake and subject blur, and consider stabilization if available),
• Set your aperture (avoid the widest aperture as well as the apertures that cause diffraction),
• Set your ISO sensitivity (the lower the better, even if that means using a tripod or a flash),
• Reduce vibrations as much as possible (gentle pressure on the shutter release, self-timer, remote control…).

Don’t forget that a good photo is not necessarily one packed with so much detail that you can count every blade of grass and every hair on someone’s head… Above all, it is a photo that conveys a certain emotion. Focus is the first priority, especially if you are using large sensors and long focal lengths with wide apertures. Another important point: many of you will want to view your images at 100% in software or on your camera, which can make a lack of detail more visible when there is one. Remember one thing: the people who look at your photos will rarely see them at such large magnifications. Also, as mentioned in the article on megapixels, the more you enlarge, the more likely you are to see a lack of detail, and the less you enlarge, the less likely you are to notice it. Do you often show your friends A0 posters of your vacation photos?

When it comes to lens quality, luckily, many testing websites are available online and can give you valuable information about their characteristics, especially sharpness. But be careful with some websites, even if they look serious, because they may not always follow a strict methodology. For example, many forget the last sentence of the previous paragraph and what it implies when comparing 100% crops from lenses tested on cameras with different resolutions. A serious site like DxO is useful because it performs tests in labs, without the influence of shooting conditions, and then standardizes the results to compare equipment fairly. Lensrentals is also one of the rare sites that tests several copies of the same model in order to account for variation between samples. Be careful, though: these websites can be quite technical, and you need to know how to interpret their results for them to be truly useful.

I hope this article will help you use your equipment to its full potential and make you realize that with great power comes great responsibility… Ah no, that’s Spider-Man! What I really meant is that good photography involves a lot of skill and experience long before it requires a big, high-performance camera and expensive lenses that look like bazookas. It is also better to have a beautiful photo full of story and emotion than a bland photo that is sharp, noiseless, and blur-free, isn’t it?

See you soon,

Written by Sylvain PONS

I've been passionate about photography since 2010, learning as I went along. Today, I dedicate myself to guiding others in their choice of camera gear and sharing a variety of tips to improve their photography skills.

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