There is a big difference in size between a deer, a fox, a cat. Could you ID a fox definate at 150 yards, in some weeds? Just wondering thought about 1 myself. We put the 100 lumin tactical lights from Walmart that comes with 3 lense and we can ID a target easy to 150 yards mounted and it was 30 dollars, and 11 for the scope mount. That light is supposed to be like 500 lumins, if i'm not mistaken.