MacMini2054,
Thanks for those details.
This is done automatically, but you can also choose Ultra Wide camera (.5x) manually.
"Shooting macro in Photo and Video modes is automatic — just move your iPhone close to the subject and the camera will automatically switch to the Ultra Wide camera if it's not selected, while maintaining your framing. To shoot macro slow-motion or time-lapse videos, select the Ultra Wide camera (.5x) and move close to the subject.
You might see the Camera app transition to the Ultra Wide camera as you move your iPhone close to or away from a subject. You can control automatic macro switching by going to Settings > Camera, then turning on Macro Control. With Macro Control on, your Camera app displays a macro button
when your iPhone is within macro distance of a subject. Tap the macro button to turn off automatic macro switching, and tap it again to turn automatic macro switching back on."
About the Camera features on your iPhone - Apple Support
If you are looking for more control or details when switching, we encourage you to leave feedback to let your ideas be know for possible future changes or enhancements: Feedback - iPhone - Apple
Take care.