Have an old iPhone? It might not support iOS 15 and you'll miss out on these features

This fall for tech lovers means new iPhones, which also usher in the arrival of a new version of iOS.

Apple revealed the first details of iOS 15 during an online keynote address last month for its annual Worldwide Developers Conference.

The update for Apple's mobile operating system will include features such as the ability to take FaceTime calls from Android devices and upgrades to notifications.

However, not every feature will work for every phone. As Apple explains in the fine print in a preview for iOS 15, if you don't have an iPhone with an A12 bionic chip or later, some options won't be available.

So which phones have the A12 chip and up? Everything from the iPhone XS and XR and beyond is covered. But if you own an iPhone X or older? You're out of luck.

Here's a look at some of the key iOS 1features you'll miss if you own an older iPhone:

Spatial audio offers a richer audio experience attempting to replicate the sound of a friend or family member in the room. Users of older phones also won't have access to Portrait Mode.

Most notable will be the absence of immersive walking directions, where your iPhone will help guide you using augmented reality. Also missing are more detailed maps with information such as elevation, trees, buildings and landmarks.

This feature will allow owners of newer iPhones to look up text within photos or screenshots and highlight them for more information.

Apple's Weather app will offer more animated backgrounds, which they say will better illustrate concepts such as the sun's position, clouds and precipitation.

A lot of the upgrades that make Apple's voice assistant better at processing your voice won't be available on older iPhones. They will also miss offline support.

When users currently attempt to dictate text, it times out after 60 seconds. Owners of newer iPhones will soon be able to do this for an unlimited amount of time.

The feature that will only be available on iPhone 8 and later models measures how you walk to determine your risk of falling.