Ever since Apple introduced its first dual-camera phone, the 7 Plus, it has been giving us a cropped version of the wide-angle camera at the touted 2x magnification when the light is dim, as the telephoto lens has narrower aperture, and a zoomed-in picture with it just wouldn't come out as good.
7 Plus, and Apple's latest and greatest iPhone X. That one has a more capable sensor/lens combo, and more image processing power to get advantage of it, so the "cropped" zoom shouldn't appear as often as it does with a 7 Plus, right?The amount of light needed for the telephoto to get engaged in an "optically" zoomed photos is decided by the camera algorithms, and varies with each situation, so a photog decided to measure if there is any difference between the
Well, correct, the setup of studio lighting that was used revealed that the camera of the iPhone X needs roughly a quarter of the light that the iPhone 7 Plus required for the telephoto zoom to kick in - 16 lux vs 88 lux - or about two light stops less, as photographers would say. This means that you will rarely see a cropped image of the wide-angle cam, instead of a true telephoto zoom in low light with the iPhone X, proving its camera more useful when you are out at night, and when you want to get closer to a subject without stepping forward.
source: Studio Neat