3 Popular Focusing Techniques

By Caroline Schmidt. Posted

1. MANUAL FOCUSING

Autofocus is fantastic, let’s face it, when a camera does such a reliable job why would you want to introduce human error? Well some scenes do require the ultimate control only available from manual focus. Even the most advanced AF systems are not without their bugs and can struggle in certain conditions, so it's even more common for entry-level DSLRs with few cross-type sensor to trip up now and again. Low light is a common scenario as there’s often not enough contrast or light
for AF to lock focus causing a lens to ‘hunt’. Close-ups and macro photography are similar, as are transparent subjects such as glass, or areas with distracting areas of contrast such as reflections. With static subjects, as you've more time to refine the degree of sharpness you need, switch from AF to manual focus to stop your lens struggling. It's a good approach for close-ups too as depth-of-field is naturally shallow making it easier to misfocus. If you want to engage your AF for accuracy, once you've locked focus, you could switch the lens to manual focus to stop it from hunting between frames. In low light, if the camera's Assist Beam isn’t enough to help AF acquire initial focus, try shining a light on your subject to secure focus and then switch to manual focus for consistency. Remember, though, if you recompose, change the distance from your subject or your subject moves, you’ll need to refocus. It’s a tricky method and requires precision, especially with wide apertures, but can deliver consistently good results if used well.

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2. DIFFERENTIAL FOCUSNG

This is a fancy way of saying that you select your AF point to control your plane of focus while using a wide aperture. By moving a focus point over the area in your image that you want sharp, and employing a wide aperture to ensure shallow depth-of-field, you’ll create an image that has a small area of focus surrounded by blur. If you left the focusing to your camera, you’d typically end up with the subject closest to the sensor sharp and the rest of the image soft, however, it’s rarely this area that you want in focus. By using selective focusing, otherwise known as differential focusing, you can place your focal plane anywhere in the frame – not just the foreground. It’s a great technique to master for creating depth in an image as you can often blur the foreground and background whilst keeping focus on the middle ground. With close-ups such as full-frame portraits you’ll be able to focus past the nose and lock onto the eyes; for wildlife you can shoot through trees and foliage to pin-point your distant subject with a wide aperture.

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3. HYPERFOCAL FOCUSING

If you’re a landscape photographer you’re probably very familiar with the term hyperfocal focusing or hyperfocal distance, even if you don’t know exactly what they are. It’s a vital concept to master if you want to achieve maximum depth-of-field without resorting to smaller apertures beyond f/16, which introduces quality-degrading effects such as diffraction.

Normally if you focus on the foreground at f/11, the background will be blurry and vice-versa, unless you calculate the precise point at which to focus that puts everything from half that distance all the way to infinity in focus – this point is called the hyperfocal distance. It’s not easy to calculate but there are a few techniques that can help. Some photographers like to ‘guesstimate’ by focusing a third of the way into a scene so that focus extends in front and beyond, or by doubling the distance from the foreground subject that you want in focus. For instance, if there’s a rocky outcrop you want sharp six feet away, you know you need to focus 12 feet away using a mid-aperture. This is pure estimation, but if you want to get precise you can delve into complex calculations; however for now we’ve a table you can use as a quick-look guide. Aperture and focal length both contribute to the hyperfocal distance and guides like these can help you quickly cross-reference the focal length and f/stop to give you your focus distance in feet. You then apply this distance to the focusing scale on the barrel of your lens manually. Alternatively, there are smartphone apps such as Hyperfocal DOF to help you calculate it on the go.

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