Always have the exact pixel dimensions at hand for any device with the Screen Size Helper, that even gives you a template you can use in apps like Sketch, Figma, Adobe XD, Photoshop or Invision.
By default, the dimensions in the Screen Size Helper matches the physical device. But what if you want to zoom in, really close?
Simply choose a multiplier in your design app - 3x should be more than enough for really close shots.
If you import a higher-than-native screenshot, make sure that you're using vector layers in your design app, allowing infinite scaling. If you just have a screenshot from your phone, you won't get the zoom boost you deserve.