Hyperfocal focusing? Sounds a bit ‘new age‘…
It’s actually an old-school technique that helps you maximise sharpness in a photo. A camera lens can only focus to a single distance at any one time, but there’s an area that extends from that point, both towards the camera and towards the horizon, where things still look sharp. This area is known as the depth of field.
The distance to which the lens is focused makes a big difference, which is where hyperfocal focusing can help.
Where is the hyperfocal focusing mode on my camera?
It hasn’t got one. You set your lens to manual focus, then focus it to the hyperfocal distance.
And the hyperfocal distance is…?
The point at which everything from half of this distance through to infinity falls within the depth of field, and so looks acceptably sharp.
Shorter focal lengths and smaller apertures bring the hyperfocal distance closer to the camera, increasing the DoF as a result.
Longer focal lengths and larger apertures have the opposite effect, pushing the hyperfocal distance back and decreasing the depth of field.
So how do I know what the hyperfocal distance is?
There are a number of printed hyperfocal distance charts, such as the ExpoAperture2 ($40, www.expoimaging.com), as well as online calculators.
There’s also a wide range of free or cheap depth-of-field apps you can download to a smartphone, including Hyperfocal, DOFMaster and Depth Of Field Calculator.
Enter your camera and lens details along with the aperture, and you’ll get your answer.
How can I tell if my lens is focused at this distance?
Many lenses have a distance scale window built into the lens barrel. These aren’t a patch on older manual lenses, which have more detailed DoF markings, but they enable you to place the focus in roughly the right area.
None of my lenses have a scale…
That makes it more difficult, but not impossible. You can measure the hyperfocal distance using a tape measure.
For full accuracy, you need to do this from the ‘focal plane’ (the camera sensor) rather than the front of the lens, but your camera should have a focal plane marker near the viewfinder. Look for a small circle with a line through it.
You could also invest in a laser measuring tool, or buy a second-hand lens with distance markings. Alternatively, just guesstimate!
The viewfinder looks blurred when my lens is focused at the hyperfocal distance. What’s going on?
The image in the viewfinder is always at the lens’s largest, brightest aperture. The lens is only switched to the aperture you’ve set when you take a picture.
However, most digital SLRs have a DoF Preview button, usually near the lens mount. This temporarily sets the lens to the f/stop you’ve dialled in, enabling you to see what will be sharp in the image.
The viewfinder gets darker as the aperture gets smaller, though, so it’s better to use the camera’s Live View function.
Live View makes it easy to set the near-as-dammit hyperfocal distance. Focus on the furthest part of the scene you want to be sharp before pressing the DoF Preview button, then manually pull the focus closer until the nearest part of the scene you want to appear sharp slides into focus.
Being able to magnify the image on the Live View screen means you can focus with precision and check both the background and the foreground for sharpness.
What if neither the foreground nor the background looks sharp?
Setting a smaller aperture extends the depth of field, although you’ll need to change the hyperfocal distance.
Avoid using the smallest aperture available: this increases diffraction, where light essentially gets bent out of shape by the diaphragm blades in the lens. You’ll get soft pictures despite the gain in depth of field.
Many landscape photographers avoid going higher than f/11, which provides a sweet spot between depth of field and sharpness.
But by setting the hyperfocal distance, it’s surprising how much you can bring into focus, even with wide apertures.
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