I’m not an expert at this stuff so bear with my simplified explanation, but the iPhone 8 and 8 Plus have a new “slow sync” feature when using the flash. This essentially keeps the shutter open for a few moments longer than normal so that it can capture more color from an entire scene, not just what the flash hits directly.
While I haven’t been able to get a good photo where the background changes much, I did take some selfies last night to see how the front facing camera and flash did on an iPhone 7 Plus and iPhone 8 Plus. Despite not getting the full benefit of the slow sync shutter, these do show how the new iPhone’s camera sensor handles flash better than any previous iPhone.
The difference is noticeable on my face in each shot here. The iPhone 7 washes me out, and I look even paler than I already am. The iPhone 8 does a much better job of making me look more natural. Frankly, I think the iPhone 8 images look so good it doesn’t even look like a flash was used at all. I assure you it was pitch black when each of these photos was taken though, almost all the light in these shots was made by the flash.
I like this so much I’ve actually turned the flash to auto on my iPhone for the first time ever. This is a fantastic new feature, and I like it so much I’m willing to share 6 not-super-flattering selfies to show it off!