Not sure if this helps at all, but I run a simrad on my night rig with a PVS14 to scan. A couple months ago we were calling and partner called out a double on a hard charge 500-600 out. He gave me a location, and by time I was turned and on them they were roughly 400 yards or so. By that time we were immediately able to tell they were domestic. Body size, posture, and tails were dead give aways. By time they were at 300yds and closing it was unmistakable.
I have not hunted with thermal so I have no field experience to speak of there. However I did get a chance to try out an IR repear (I believe) . It was the clearest thing ive ever looked through. I am unsure on distance, but we were looking at a group of cows at a LOOOOOOONNNNG way off. way over 1000 yards, and there was no question what I was looking at. Again, I understand there are different scenarios that effect performance, but it was wild to see.
