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Autofocus is Overrated: How to Hyperfocal Focus

Just because your camera can focus for you doesn't mean you should let it do everything. When you want to maximise depth of field, you need to know how to find and use your lens's optimal focal point—the hyperfocal distance. In this tutorial you'll learn why hyperfocal distance still matters in the age of digital, how to find the hyperfocal distance, and how this method of focusing works in the real world.

Going Hyperfocal

The hyperfocal distance of a lens is the distance from the camera lens to an optimal point of focus that maximizes the depth of field in the image. By focusing on this optimal point—the hyperfocal point—as much of the scene as is possible for that lens and aperture setting will be in acceptable focus from near to far. If that's a bit dense don't worry, I'm about to unpack it all.

There are several types of photography where the hyperfocal distance is useful, including: architectural and landscape photography, night photography, street photography, and product photography.

Why Not Just Use Autofocus?

Modern autofocus is awesome and has removed much of the manual finessing from focusing shots. Autofocus, however, only takes care of one step in composing a focused image: it focuses the lens on the point chosen for it. Autofocus uses edge or contrast detection to sharpen focus, so if left to choose the focal point for itself, autofocus will choose to focus on the most prominent details in the scene. Your camera's programming may override that default by choosing the focal point based on certain algorithms; for example, if something like a face appears in your scene, your camera may choose that point as the focal point. But there are plenty of situations where autofocus and your camera's programming will not give you the best point of focus or the point of focus that meets your artistic intent. 

To maximize the value of autofocus and get what you want in the image in focus, you need to choose the focal point. And if your choice is to have maximum depth of field in a scene—as much as possible from foreground to background in focus—you need to understand hyperfocal distance.

Why Not Just Use a Narrow Aperture?

If maximum depth of field is what you're after, you might be inclined to close the lens's aperture as far as it will go (f/22, for example) and focus 1/3 of the distance into the image. The 1/3–2/3 rule of depth of field says that 1/3 of a lens's range of acceptable focus exists in front of the focal point and 2/3 of the range is behind the focal point. The combination of that and a small aperture (which increases depth of field) should get most of the scene in focus, shouldn't it? Well, yes. And no. 

f11
Even at f/11 on a 40mm lens it's possible to get a background that's out of focus.

A range of focus might not—and often doesn't, even at the maximum depth of field—cover the whole scene from foreground to background. So by focusing 1/3 of the distance into the scene, something in front or behind or both could still be out of focus, and that something could be an important part of your composition. Also, the range of focus is not affected just by aperture, but also by a lens's focal length: the longer the focal length, the narrower the apparent range of focus. So even by using the smallest aperture, depending on the focal length, you might still be working with a relatively narrow range of focus. 

focus far
Or, if you focus at a point in the distance, you can get a foreground that isn't sharp.

Using a small aperture also creates its own problems. Remember, the basic job of a lens is to force light through a small, sharp hole. It's not easy: there are always trade offs you have to make to make an image.

To achieve proper exposure, a small aperture needs to be compensated with a slower shutter speed, increasing blur, or with a high ISO, increasing image noise. The other problem caused by small apertures is diffraction—a bending and scattering of light waves as they pass through the tiny aperture. The small details within the range of focus will begin to blur and light artifacts will appear. (You can use this effect intentionally to create rays of light around a light source.) Closing the aperture creates greater depth of field but at the cost of defocus and artifact within that range of focus.

While there wasn't a hyperfocal distance for my lens at f/11 that would get everything perfectly sharp, you can see that by focussing on a point a few metres into the scene I've managed to get the foreground completely sharp and the background a lot sharper than before.

By being more selective about where to focus—at the hyperfocal point—you can make choices about focal length, aperture, and what in the image will be in focus.

Acceptable Sharpness

I discussed sharpness and acceptable sharpness at length in my tutorial on how to calculate the sharpest aperture for any lens. The concept of sharpest aperture and hyperfocal distance are very much related. Let's briefly recap a few fundamentals about how lenses work:

  1. A lens has only one plane of focus. The plane of focus is two-dimensional (flat) and extends parallel to the camera's sensor (or film) and perpendicular to the lens.
  2. A lens focuses light onto the sensor plane to create an image. All light from the scene passes through the lens, but only light from the plane of focus is resolved. That is, only objects at the plane of focus appear as sharp little points of light on the sensor.
  3. Light that enters the lens from parts of the scene that are not on the plane of focus creates slightly larger, blurry dots on the sensor. These dots of light are called circles of confusion. We call these unresolved areas "out of focus."
  4. Larger apertures produce larger circles of confusion; smaller apertures produce smaller ones.
  5. When the circles of confusion are small enough, they become indistinguishable from the points of light that are in focus. This creates "depth of field," a deeper range of the scene that appears to be in focus. (More things are acceptably sharp.)

Given a number of factors, we can calculate precisely what parts of a scene will appear acceptably sharp. By focusing on the hyperfocal distance, your depth of field—the range of your scene that will appear to be in focus—will extend from halfway between your camera and the hyperfocal distance to infinity. For example, if your hyperfocal distance is 2.6 metres, your range of acceptable focus will extend from 1.3 metres to infinity.

In the diagram above, we can a rough idea of how focussing close, far and at the hyperfocal distance will effect the image. The red areas are out of focus and the green are in focus. In the top example, the camera is focussed close so the subject will be in focus but the background won't. In the second example, the camera is focussed far so the background will be in focus and the subject won't. In the bottom example, the camera is focussed hyperfocally. Some very close objects won't be in focus, but everything else, including the subject and background, will be.

You can learn to calculate these distances in your head, and pre-visualize them in your minds' eye, too. However you calculate, you can then use that range of what will be acceptably sharp to make better pictures. That's hyperfocal focusing.

How to Focus on the Hyperfocal Distance

Calculating hyperfocal distance, like most photographic maths, can be tricky. This is especially true when you start taking complex factors like diffraction into account. Plus, hyperfocal distance varies depending upon the size of the film or sensor being used, the focal length of the lens, and the chosen aperture!

One oft repeated guideline for finding a distance that approximates the hyperfocal distance is to focus on an object a third of the way into the scene. This relies on the 1/3–2/3 principle of depth of field that we discussed earlier. This rule is fine for simple shots, but if you need to maximise the depth of field, the rule might not be sufficiently accurate.

To find the true hyperfocal distance of your lens, you need to use a calculator or a chart. If you’re using an iPhone, I recommend TrueDoF-Pro by George Douvos. You can use it to calculate the hyperfocal distance for any focal length and aperture combination while you’re out in the field. 

calculator
Outsight's hyperfocal calculator. For a 50mm lens at f/5.6, you need to focus 48.8 feet away (the hyperfocal point) to achieve the maximum depth of field.

Another option is to use Outsight’s hyperfocal calculator and chart maker. You can use the calculator to work out the exact hyperfocal distance of any combination of focal length and aperture and use the chart maker to create a table of all the common pairings. You can then print the table and put it in your camera bag or save it on your phone.

If you are using a prime lens (a fixed as opposed to zoom lens), you may have hyperfocal markings on the lens body. These are a lot more common on old lenses. You can see an example below. 

hyperfocal markings
The hyperfocal markings are in the middle, either side of the green line. Image Credit: Nigel Wade.

When you focus the lens to a certain distance, the focus distance will line up with the green line. Right now, the lens looks like it's focused to about four feet (the small green four under the green line). The lines moving out from the green light represent the range of focus for that given aperture. Everything between the two 16 lines will be in focus at f/16, everything between the two 11 lines will be in focus at f/11. 

Once you’ve worked out the distance to your ideal focal point, use the distance scale on your lens to set focus as close as possible to that distance. You are not trying to focus ON something at the hyperfocal distance; rather, you set the focus to the hyperfocal distance by using the markings on your lens. Depending on the accuracy of the scale on your lens, this may require a few test shots to fine tune. 

Be sure to turn autofocus OFF before you set your lens!

If your lens doesn’t have a distance scale, things get a bit trickier. The workaround is to calculate the hyperfocal distance for your most common apertures, set your camera up that distance from an object, focus on the object, and then mark the focus ring yourself with a small dab of paint, nail polish, or liquid paper. You can then use your DIY markings as a stand-in distance scale.

Hyperfocal Focusing in the Real World

Now that we’ve addressed what the hyperfocal distance is and how to find it, let’s look at how to use it.

Architectural and Landscape Photography

While the hyperfocal distance will give you the broadest range of acceptable sharpness, it won’t give you the absolute sharpest image. You should only use the hyperfocal distance with scenes where you need objects in both the foreground and the background to be in focus at the same time.

With architectural and landscape photography, you are regularly working with situations where you need the foreground and background to be acceptably sharp. Whether you’re photographing a building in a city street or a flower surrounded by mountains, the principles remain the same: you want everything in focus. Focusing on the hyperfocal distance will give you the best results in a single frame.

If you need just the foreground or just the background in focus, you can safely focus on that area of the image or follow my advice on getting the sharpest possible image.

autofocus sucks
I used the hyperfocal distance and a narrow aperture for this image so that the foreground ridges, village, and sky would all be tack sharp.

When you’re previewing a scene through the viewfinder of an SLR (digital or not), you are seeing things through the widest aperture of the lens. This makes it easier to view scenes in low light, but it makes them harder to pre-visualise accurately. If you are working with the hyperfocal distance, use your camera’s Depth of Field Preview button to see how the image will really look. Although the preview will be small, this will give you an idea of what areas will be in focus. Depending on your aperture setting, some objects especially close to the camera may still be out of focus.

Night Photography

For nighttime and astrophotography, understanding the hyperfocal distance is incredibly important. You have to work with wider apertures in the dark to let as much light in as possible in order to get a good exposure. This means the situation isn’t ideal for perfectly sharp images. If you’re just capturing celestial objects, you can get away with focusing at infinity, but if there’s anything in the foreground of your shot, you need to use the hyperfocal distance to capture both the sky and the earthbound objects.

Street Photography

The hyperfocal distance can be a great tool for street photography, especially if you’re using a rangefinder camera. Simply set the camera to focus on hyperfocal distance that will let you photograph inside a particular distance for your given light conditions. If your subject is inside your range, you can raise the camera and compose without refocusing at all. This lets you capture those incredible, fleeting moments of life on the street that others are too slow to catch.

Smartphone Photography

Hyperfocal focussing is good for smartphone photography as well. With their small sensors, it's also a lot easier to do than with a DSLR! The iPhone 7, for example, with a 4.15mm lens, has a hyperfocal distance of around 2.26 metres. Focus there and everything from 1.12 metres to infinity will be acceptably sharp. Other smartphone cameras will have similar   hyperfocal distances. Since almost everything is going to be sharp unless you focus very close to the camera, you might as well make everything sharp.

Product Photography

Product photography is another area where knowing the hyperfocal distance can let you work quickly and efficiently, especially in close quarters. For product shots, you often need to display everything sharply rather than have a more artistic image with a shallow depth of field. By understanding the hyperfocal distance, you'll be able to get as much of the object in focus in a single frame as possible without resorting to focus stacking and other time consuming techniques.

Wrapping Up

It’s easier than ever to avoid learning complex concepts like the hyperfocal distance of a lens. However, these concepts give you more control over creating your image, taking your photography from ordinary to exceptional. The photographers who are prepared to put in the effort to learn hyperfocal focusing will be well rewarded. Any time you want to maximise your depth of field for a given aperture, whether you’re shooting stars at f/1.8 or street scenes at f/11, calculating the hyperfocal distance is the best way to do it.

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