Best shutter speed for moving kids and pets on iPhone

What shutter speed does to a moving child or pet

Anyone who has tried to photograph a toddler mid-sprint knows the result: a sharp background and a smear where the child used to be. Shutter speed is how long the camera collects light for one photo. It is written as a fraction of a second, so 1/500 s is faster than 1/250 s. At a fast speed, a running child is caught mid-stride. At a slow one, the same child smears across the frame. That smear is motion blur, and it is a common reason a photo comes out soft even when focus is right.

There is no single best shutter speed for moving kids, because it depends on how fast they move, how close you are and how much light you have. The chart below gives you a place to start. These are widely taught rules of thumb, not measurements of your child or your dog, so take a shot, zoom in on the eyes and go one step faster if they look soft.

A starting chart

Two things shift these numbers. Closer and more zoomed in means more blur, because the same movement crosses more of the frame, so if a child fills the picture, lean toward the faster end. And for a still subject you can go slower, but below about 1/60 s your own hand shake starts to blur the photo, so brace your elbows.

Set it on your iPhone

You need a camera app that shows a shutter speed control. If yours doesn't, a manual camera app can add one. AnyFront Camera is coming to the App Store on 23 October. The camera and all its manual controls are free on every compatible iPhone.

In AnyFront, a control row sits above the lens chips: ISO, SHUTTER, WB, FOCUS and EV.

1. Tap SHUTTER. A dial opens, with an AUTO option and a close button.
2. Slide the dial to a speed from the chart.
3. Look at the live histogram. If the graph piles against the left edge, the picture is too dark. The next section covers that.
4. Take the photo, then adjust one step at a time.

Pay for speed with light first, then ISO

A faster shutter lets in less light. Halving the exposure time, from 1/250 s to 1/500 s for example, halves the light, so the picture gets darker. Two things bring the brightness back.

Light comes first. Move your subject next to a window, open the curtains or take the game outside. Lamps add light too, but they can turn skin orange, which our guide to fixing yellow indoor photos explains.

Then ISO. ISO is how sensitive the camera is to light, and doubling it, say from 400 to 800, makes up for one halving of the shutter time. The price is grain, because a higher ISO adds noise. A little grain is easier to live with than a blurred face, so raise ISO until the shot is bright enough at the speed you need, and no further.

Check the shot before the moment passes

Don't trust the small screen alone. After a test shot, open it and zoom in on the eyes. If they are crisp, your speed is doing its job. If the eyes look soft, or hands and feet are smeared, go one step faster.

Two aids help while you shoot. Focus peaking outlines the edges that are in focus, so you can confirm they sit on the eyes and not the ears. Zebras, the stripes in the picture below, mark the brightest areas, so you can see if a window has blown out. AE/AF lock holds focus and exposure where you set them. Tap to focus on the spot a child or pet will reach, such as the bottom of the slide or the doorway, use AE/AF lock, and press the shutter when they arrive. That is more reliable than chasing them across the frame. Shoot several frames, because one of them is likely to be sharper than the rest.

When it is still blurry

Work out which kind of blur you have.

• Only the subject is smeared. The shutter is too slow. Go one step faster, for example 1/500 s to 1/1000 s, and add light or ISO to keep the picture bright.
• Everything is soft, including still objects. That is hand shake or a smudged lens. Hold the phone with both hands, brace your elbows and wipe the lens with a soft cloth.
• The ears are sharp but the eyes are not. Focus landed on the wrong thing. Tap on the nearest eye and check it with peaking.
• The subject was sharp, then moved. They left the spot you focused on. Pre-focus where they will be, use AE/AF lock and shoot several frames.
• It is sharp but dark or grainy. You asked for more speed than the light can give. Add light first, then ISO.

Quick checklist

• Start from the chart: 1/250 s indoors, 1/500 s outdoors, 1/1000 s or faster for jumps and galloping.
• Zoom in on the eyes after a test shot.
• Add light before you add ISO.
• Raise ISO only as far as the shot needs.
• Pre-focus where they will be, then use AE/AF lock.
• Shoot several frames.
• Change one step at a time.

The short version

Pick a number from the chart, check the eyes, and move one step at a time. For tips on getting small humans and animals to look at the lens, see photographing toddlers and kids and how to get a dog or cat to look at the camera. Dark coats need their own exposure care, covered in photographing a black dog or cat. Every control mentioned here is on the features page.