Studio Neat:

With the improved sensor, wider aperture, and added optical image stabilization on the telephoto lens in the iPhone X, I wanted to see if Apple’s frequency of presenting a cropped image at 2X was reduced at all. The answer: yes. But by how much?

I created a test to hopefully get a rough idea of how much light is required before an iPhone 7 Plus and iPhone X decide to switch to their respective telephoto lenses in 2X mode.

One of the things I’ve seen people talking about is the much improved low light capability of the iPhone X. This is a good description of what happens in low light with the iPhone 7 Plus and iPhone X and how the X deals with it much better.