Mchull is spot on ...
Thing is greb whilst your are seeing some wildlife with the torch...your not seeing it all..
Just a few week back me and my work colleague were testing this stuff out...and I was using a light force blitz 240 halogen...
Thermal on ....rabbits everywhere...lamp on...some at 50.. 100 yards out vanished...
Don't get me wrong I've killed game with all sorts of lamps ..got a couple of led lamps myself...even a short while ago had a few rabbits with a £10 led torch that had a 20 yard beam...
The ground can make a difference as well...and of course the