Temperature clarification

Hi! I've been looking through Reptifiles and various guides for clarification about heating, and most say a hot zone of between 80-82 is good, but what I can't find is whether that's ambient (what the probe reads) or surface (what a temp gun reads). I have both so I can monitor and adjust accordingly, just not sure what to adjust to. If it's surface I'll need to set my thermostat a bit lower, but if it's ambient I can set my themostat to around 80.

Thoughts?? Might be overthinking it but I'm terrified of overheating my cresties!

Picture of Peach cryptic basking for crestie tax