Difficult to say exactly.
Depends a bit on conditions but at 500m you can see if it is a pig or a deer. Where I use it I just need to identify it is an animal and then I will get closer to properly identify. I spotted a mob of pigs tonight from about 2km away. I knew they were pigs as they couldn't be anything else in that area. Stalked to within 100m and was about to shoot when the wind betrayed me.
I also use a Hikmicro Thunder TQ35C scope (it can be used as a monocular, a scope or a front clip on) and it is on par with the Infiray picture wise but doesn't have as wide a field of view or range finder.
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