Snap Focus and Zone Focusing

This is the lesson that turns the GR from a good camera into a street weapon. Autofocus, even fast hybrid autofocus, takes time and makes a decision you might not want. Snap focus removes the camera from the equation entirely: you decide where the focus is in advance, and the shutter fires the instant you press it, with zero focus lag. Combined with a small aperture, it makes a deep zone of the scene sharp without the camera ever needing to think.

The killer setting

Here is the one to tattoo on your memory: f/8 at 2m on the 28mm-equivalent lens gives you sharp focus from roughly one metre to infinity. Set snap focus to 2m, set the aperture to f/8, and anything from about an arm's length away out to the horizon is acceptably sharp. You never focus again. You just frame and shoot. This is the legendary GR setting, and the visualizer on this page lets you see exactly why it works.

Why it works: depth of field and hyperfocal distance

When you focus a lens at a given distance, a zone in front of and behind that point is also acceptably sharp. That zone is the depth of field, and it grows as you stop the aperture down. There is a special focus distance, called the hyperfocal distance, where the depth of field stretches from half that distance all the way to infinity. Focus there and you get the maximum possible range of sharpness.

For the GR IV's 18.3mm lens at f/8, the hyperfocal distance is about 2.1m. That is the secret. When you set snap focus to 2m, you are focusing almost exactly at the hyperfocal distance, which is precisely why everything from about a metre to infinity comes out sharp. The 2m setting is not arbitrary; it is the engineered sweet spot for f/8 on this lens.

Choosing your snap distance

The seven snap distances each have a use.

1m and 1.5m are for close, intimate frames, arm's reach, a face across a cafe table, a detail. At wide apertures the zone is thin, so be deliberate.

2m is the all-rounder, the legendary setting, your default.

2.5m is versatile for groups and slightly more distant subjects while keeping faces sharp.

3.5m and 5m are for street scenes and cityscapes where your subjects are further away, a piazza, a portico receding into distance.

Infinity is for landscapes and distant architecture where nothing close matters.

Setting it up on the camera

Assign Snap Focus Distance to a function button so you can change it without diving into menus, the situation changes faster than a menu does. Then enable Full Press Snap. This clever feature means a half-press uses autofocus as normal, but a quick full press jumps straight to your snap distance and fires. You get autofocus when you have time and instant snap focus when you do not, from the same button. It is the best of both worlds.

When not to use snap focus

Snap focus is a daylight technique. It depends on a small aperture, f/8 or f/11, to create the deep zone of sharpness, and a small aperture needs light. In low light or at night you have to open the aperture wide, f/2.8, which collapses the depth of field to a thin sliver. At f/2.8 your one-metre-to-infinity zone shrinks to a few centimetres, and snap focus at a guessed distance will miss. After dark, switch to single-point autofocus and let the camera's new phase-detect system do its job. Snap focus is for the sun; autofocus is for the dark.

Practice the distance estimate

The one skill snap focus demands is judging distance by eye. Practice it constantly: look at a person and guess whether they are at 2m or 3.5m, then check by stepping it out. Within a week you will estimate two metres as instinctively as you judge an arm's length. Use the visualizer below to internalize how the in-focus band grows and shrinks as you change aperture and distance.