Science

Why iPhone 8's 'Slow Sync Flash' is a Game Changer

A hidden feature could prove to be one of the iPhone X's most exciting.

Getty Images / Justin Sullivan

Apple’s new iPhones contain a feature that’s flown under the radar, but could prove to be one of the biggest upgrades to the camera flash in years: slow sync. The iPhone 8, 8 Plus and X all support the nifty addition, which stops flash photo subjects from looking so weird. It’s a simple change, but one that could encourage you to rethink iPhone photography.

Normally, when the iPhone takes a photo with flash it shines the rear LED and captures the image at the same time. When taking a photo of a person in a room, this results in a subject that appears well-lit with plenty of detail. But if the person is standing in a much darker room, the background can sometimes appear pitch black. It’s fine for capturing faces, but especially in photos taken at dimly-lit parties the surrounding context is lost in the process.

Slow sync flash fixes this. Professional photographers will be used to this feature already, which involves setting the flash off at a slower shutter speed. This lets in more light, including from the background, which evens out the light differences.

Look at this comparison shot, taken by photographer Austin Mann, that really shows off the power of this feature:

“This is a fantastic advance that’ll quietly impact the quality of the images we shoot indoors, at night, at parties, etc,” Mann said in his review of the iPhone 8 camera. “People will look better and images will be richer in color and ambiance. I’m really excited to see this improvement.”

Slow sync flash isn’t perfect, though. The subject needs to be relatively still, as the camera is using a slower shutter speed that can blur motion. That blur can work in its favor, though, as it allows for cool effects otherwise not possible.

The new generation of iPhones also supports Portrait Lighting, an artificial intelligence-powered simulation of studio lights that gives photos a professional look. It joins the existing Portrait Mode feature introduced on the iPhone 7 Plus last year, which blurs the background of subjects by sensing the depth in an image, to offer more features typically reserved for high-end DSLR cameras. A photographer’s bag in your pocket? It just got one step closer.

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