My Bushnell 450 works easy out to 200 and picks up small things. When I am in a blind or sitting on a hill top. I pull out my range finder and hit proment trees, big rocks, telephone poles, fence posts, what have you.
That way as anything walks by them or with in that I will know that I can hit the deer, the turkey is with in range or the ducks are close enough or the decoys are not too far out.
The down side of the unit are it takes 9V batteries (the rectangle ones that have the two poles on the top) and it is not water proof.
I wish some company would make a Range finder, Flash light , and GPS / Radio that all takes the same batteries.