One Trick to Get Easy Long Exposures Out of an iPhone

Long exposures are useful to convey a sense of motion in photos, whether that's bodies of water that seemingly look like glass or car taillights whooshing by in a street scene. The iPhone allows you to create scenes like this easily. It's just a bit hidden.

While often, the Night mode on an iPhone activates in low light to drag the shutter, there's very little way to control the image that's captured, and without the steadiest of hands, things can get dicey quickly.

There's another way, though, to capture motion that doesn't involve as much guesswork, and it's using a feature that, as a photographer, I generally don't think too much about, and that's Live photos. By default, shooting a live photo on your phone creates a few seconds of video around the photo, and when you pull it up to view, it will play those seconds by tapping on the screen. It's an effect I love to catch the fun moments my children have around the actual photo itself, a nice video memento for the future to remember a point in time.

However, there's another benefit to shooting live photos that most casual users and even professional ones don't know about. Using a Live photo gives the file enough data for computational imaging technology to generate a simulated and very convincing long exposure photo. The photo above, in its standard form, looked like this before setting it to a long exposure after the fact.

The movement of the taxi and the people created a series of beautiful motion blurs. This useful for clearing crowded streets as well.

How do you activate this feature? The initial capture must be a live photo (the circles-within-circles icon on the top right of the camera app, if you're holding the phone vertically). Once you capture that, here's where you'll find the option to make it a long exposure:

One tradeoff that you can see from the example above is that this technique results in some slight cropping of the photo so that all the elements align and some of the shake from hand-holding the camera is removed, so if you're using this mode with long exposures in mind, be sure to shoot a little looser than you intend the final product to be. If you're shooting people, be sure that they are very, very still, or they'll be motion-blurred too.

While it's no substitute yet for a "real" camera capturing the image with a long exposure, when your iPhone is the only camera you have on you, it can do in a pinch.

Post your own attempts at this in the comments below if you give it a try.