Having used an iPhone as my sole camera for years, I wanted to understand some of the practical differences between it and my new Canon EOS 6 Mark II. One of my big motivations for getting the Canon is for telephoto capabilities. Here are some comparison photos (apologies for the ginormous table, but I wanted to provide the full resolution).
|iPhone 3x Zoom||Canon 2x Zoom||Canon 10x Zoom|
The iPhone at 2x zoom has an effective focal length of 48mm, so it's really close to what our eyes see normally. This is why even at 3x zoom the iPhone is still significantly smaller than a camera at 100mm.