Does turning off Share My Location affect GPS tracking on iPhone?

The short answer

No. Share My Location — the Find My feature that lets someone you have chosen see roughly where you are, or lets your own devices show up when you are trying to locate one of them — has nothing to do with whether a recording app like TrailCam can read your phone's GPS position. Turning it off, on, or never touching it at all makes no difference to a hike that is already recording, or to one you start recording next.

What Share My Location actually does

Share My Location lives inside Find My, under your name in Settings, and it does one specific job: it broadcasts your position outward, on Apple's own schedule, to whoever you have chosen to share it with, and it lets your own devices find each other if one goes missing. It is a sharing feature aimed at people, not a permission a third-party app asks for. An app has no way to read from it, write to it, or be affected by whether it is switched on.

What actually decides whether an app can record your position

That is Location Services, a separate system entirely, reached under Settings, Privacy & Security, Location Services. Every app that wants your position has to ask for it there, individually, and gets granted "Always", "While Using the App", or "Never". This is the setting a recording app is actually built on, and it is the only one that decides whether a phone is willing to hand that app a GPS position at all. Share My Location is never consulted, because it was never part of the chain to begin with — a recording app asks Location Services for a position the same way whether Share My Location is on, off, or a setting you have never opened.

Why the two feel like they should be connected

Both settings live somewhere under the general idea of "location" on an iPhone, and both tend to get a second look around the same moment — packing for a solo hike, or simply wanting less of your day broadcast to other people. It is a reasonable place for the two to blur together, the same way Do Not Disturb and background recording get lumped together for feeling like they are both about the phone doing less. The actual difference is about direction: Share My Location sends your position out to specific people you named. Location Services is what lets an app on your own phone read a position for its own use. Turning off the outward-facing one changes nothing about the inward-facing one.

Things that trip people up

• Assuming Share My Location has to be on for any app to use GPS at all — it does not; it only controls what other people or your own other devices can see, not what an app on the phone in your hand is permitted to read.
• Turning off Share My Location before a hike expecting it to make the walk untracked in every sense — a recording app you have separately given Location Services permission to keeps working exactly as before; only the Find My sharing side turns off.
• Confusing this with Location Services being switched off entirely, which does stop a recording app from receiving new positions — that is a genuinely different setting, with a genuinely different effect.
• Expecting Share My Location to reappear automatically once turned back on for a specific person — it starts sharing again from that point forward, the same way any position feed picks up rather than backfills what it missed.

Where TrailCam fits in

TrailCam asks for its own Location Services permission the way any recording app does, and records a route in the background whether Share My Location is switched on, off, or never set up at all — the two settings simply do not overlap. TrailCam is free to download.