When I was adding layers of insulation to my attic, I used one of those cheap IR heat scanners.
It enabled me to detect areas with heat leaks and take corrective action. Very inexpensive and effective tool.
It allows you to remotely view areas that aren't easy to reach. Or areas that are unsafe to walk on.
When it's real cold in the attic, and the house heat is turned up to 70F, leaks are easy to find, even 15-20 feet away.
But when you get closer (5 to 10 ft), you greatly narrow down the location of the leak.
Here's an example of the range resolution of one model.
At 1" spread per foot, at 20 feet, the detect zone would be 20"?
This one doesn't look that great, but by sweeping slowly across the area,
while watching the peak, you can really focus in on the leak.