Where to Focus in a Landscape Photo
One of the questions I get asked most when running landscape photography workshops is “where should I focus within the scene to maximise depth of field?” It is a good question. After all, in most shooting situations, landscape photographers are looking to achieve front-to-back sharpness so that everything from the immediate foreground, right through to the distant landscape, is recorded acceptably sharp.
There are a number of things we can do as photographers to maximise image sharpness and avoid disappointment and frustration when we later download the images onto our computers.
Let’s begin with a few titbits of general advice to help you to take sharper images. Apologies if they all seem quite obvious, but I think it is important to cover all bases.
Firstly, use a good, sturdy tripod. Doing so will not only provide needed stability, but will allow you to place your point of focus with greater precision via LiveView.
Also, check that any in-camera or lens image stabilisation (IS) is switched OFF. Leaving it on not only wastes battery life, but on some designs leaving it ON while using a tripod can actually soften your shots. Why? Well, image stabilisation is looking for vibrations in order to reduce them, but if the lens can’t detect motion the system can inadvertently cause blur. This is because the IS lens group is unlocked and can be moved by the electromagnetic coil surrounding these elements. By switching IS OFF, you effectively lock the IS lens group into place and image sharpness can’t be affected.
Finally, don’t physically depress the shutter when taking your shot. Doing so can cause a tiny amount of camera motion that may soften the resulting photo, even when using a tripod. Instead, always use a cable or infrared release and trigger the shutter remotely.
Alternatively, set your camera’s self-timer to 2-sec, or use your camera’s Exposure Delay mode. In most situations, this will do the job just fine. However, if you need to time your shots precisely – for example, when shooting wave motion – exposure delay can cause you to mistime your shot.
Personally, I favour using a trigger release. One last thing – if you are using a digital SLR, lock up the mirror prior to shooting (or shoot with LiveView activated) to avoid mirror-slap causing tiny internal vibrations.
To achieve front-to-back sharpness, you need to generate a large depth of field. To help achieve this, select a smaller aperture. The smaller the f/stop, the larger the zone of focus.
You might understandably think it is best to always select the smallest aperture available when shooting landscapes – typically, f/22. However, you need to be aware of diffraction.
Lens diffraction is an optical effect that effectively softens overall image quality. Why? Well, when image forming light passes through the aperture, the light striking the edges of the diaphragm blades tend to scatter and diffract. This softens image sharpness.
At smaller apertures, the percentage of diffracted light grows larger. In other words, even though depth-of-field is increasing, image sharpness is actually deteriorating. Better quality optics suffer less, of course.
Every lens has an optimum aperture for image sharpness – typically a mid-aperture in the region of f/8. It may be worthwhile doing your own comparison tests to discover which f-number suffers least from diffraction. The effects of diffraction become more and more noticeable the larger you reproduce your shots and will affect fine detail, like foliage, most.
Don’t obsess about diffraction, but do be aware of the issue and minimise it when possible. While many lenses perform best at f/8, this setting will rarely generate sufficient depth of field for a big vista. Therefore, my starting point for a landscape photo is usually f/11. This – in my experience – provides a nice balance, being relatively diffraction free whilst creating a practical zone of focus.
In some shooting situations you may get away with a larger, sharper f-stop, while at other times you may have to employ a smaller aperture to achieve enough depth of field. However, always try to avoid your lens’ smallest aperture value (unless you are trying to create a starburst effect).
Where to focus in a landscape photo
With your camera all set up and your aperture selected, you now need to decide where to focus in the landscape scene to maximise sharpness. There are a couple of different approaches, which I will outline below.
Whichever one you adapt, I would recommend you focus via LiveView for landscapes. Then, using a single AF point, magnify your chosen point of focus and either manually or automatically focus. Personally, I favour the speed and precision of AF for landscapes, using back-button focusing.
1. Focus a third way into the frame
Depth of field – the zone of acceptable focus falling either side of your point of focus – falls approximately one-third in front of where you focus and two-thirds beyond this point. Therefore, if you focus too near or far into the scene, you are effectively wasting a slice of the depth of field available to you.
One rough and ready approach is to simply focus a third way into the frame. While this is not a particularly scientific or precise approach, doing so works surprisingly well. The problem is deciding whereabouts exactly this point is; it can be slightly hit and miss. In reality, you are better to double distance focus, which works using a similar principal, but is easier to calculate and apply.
2. Double distance focusing
This is the approach I normally adopt these days. Double the distance focusing is simple to understand and apply and a great way to equalise foreground and background sharpness. Basically, compose your shot and then identify the closest object in frame that you want recorded acceptably sharp. Calculate the distance that this point is from the camera’s focal plane and then focus twice the distance away. For example, if the closest point in your frame is a boulder 3m away, focus at 6m. Most of us are quite good at estimating distances within 10m and your calculation doesn’t have to be perfect, just close enough. You certainly don’t need a tape measure, but if it helps, try walking into the scene and count your paces – although obviously don’t do this it involves trapesing over virgin snow or sand! Often, the resulting point of focus is relatively equal to the third way in method, but double distance focusing is a more logical and reliable approach.
3. The hyperfocal length
If I had been writing this feature on maximising sharpness a few years ago, I would have been championing hyperfocal distance. This is a popular focusing technique, which was once very reliable and remains popular. It is a mathematical formula devised to help photographers maximise depth of field.
In simple terms, the hyperfocal point is the distance that maximises the zone of focus for any given focal length and aperture combination. When a lens is correctly focused on this point, depth of field will extend from half this distance to infinity.
This approach is not as complex as it might first sound. If you are using a prime lens – with good distance and depth of field scales on the lens barrel – it is in fact very easy to set. Simply align the infinity mark against the aperture marking of the selected f-stop. However, most photographers today (myself included) rely on zooms, which have rather deficient distance scales. Therefore, photographers need to calculate and estimate the distance themselves.
Thankfully, hyperfocal distance charts are readily available online and – better still – as smart phone apps. An app makes life easy; just enter the camera type (sensor size will effect the calculation), f-number and focal length, and it will calculate the distance for you. All you then have to do is focus at this distance. For more information, read our article Hyperfocal Distance: Focusing in Landscape Photos.
While the principal is still relevant, in my experience using hyperfocal focusing places too much emphasis on foreground sharpness and sacrifices too much background focus.
The formula was devised in an era before high-resolution digital sensors and assumed a modest print size of just 10×8 inches. In other words, the calculations are outdated and encourage you to focus nearer than you need to, so just keep this in mind if you employ this technique.
Also, if you apply this theory slavishly, you risk grossly misplacing your point of focus. For example, if you photograph a view where the closest point is, say, a lighthouse or rocky headland 75m away, you would massively misplace the sharpest plane of focus if you focused on the hyperfocal distance, which might be just a few meters away.
Whichever focusing technique you use, always evaluate the scene individually and apply a degree of judgement and intuition.
4. Focus stacking
Basically, you take several shots, each of which is focused at a different point throughout the scene, and then later blend them together in Photoshop (or dedicated stacking software like Zerene Stacker or Helicon Focus).
The software identifies and uses the sharpest parts of each shot to create one bitingly sharp file. Another advantage of this approach is that you can use your lens’ “sweet spot” – the aperture (usually f/5.6 or f/8) that is sharpest and most diffraction free.
The number of frames you need to take will vary depending on the focal length, aperture, and distance from the camera of the nearest object you want to keep sharp. If in doubt, err on the side of caution and take more shots than required, with a generous overlap of focus.
Whichever technique you decide to employ, it is important to understand that while focusing in the right place will maximise depth of field, it far from guarantees complete front-to-back sharpness. Remember that a lens can only focus precisely on one plane – depth of field is simply the zone of acceptable focus either side of this point.
Therefore, if you scrutinise image sharpness at 100%, your shot is unlikely to appear perfectly sharp throughout. Photographers are often guilty of “pixel peeping” – enlarging images to a great extent and then complaining they are not sharp enough. But this is unrealistic and equivalent to viewing a painting close-up and then bemoaning the appearance of each brushstroke.
Basically, what I am trying to say is that you have to be realistic.
What I would encourage you to do is replay images regularly, zoom-in to approximately 50% and scroll around the frame to check the image is sufficiently sharp overall. Doing so will either reassure you that focus is good, or help you identify and then rectify any issues with your technique.
If the foreground isn’t sharp enough, simply move your point of focus closer; if the background isn’t sharp, focus further into the scene. It is best to do this in small increments until you feel you have achieved a suitable balance between foreground and background sharpness.
In scenarios where you require a huge depth of field, due to your foreground being particularly close and prominent, you are unlikely to be able to generate sufficient depth of field in a single frame. In such situations where you need to extend depth of field beyond what you can achieve in-camera, you should focus stack instead.