Well....where is the brush. Is the light brush directly in front of the deer? Meaning the brush is within a foot or less of the deer? You say light brush...meaning....how many twigs or leaves? To be perfetly honest, if I wanted the deer, and it was clear 19.75 yards to the brush, your arrows will deflect very slightly if it is light enough brush shooting a powerful bow. Still a dead deer if the brush is where I described. That is what I envision when you say light brush. I take the shot. I agree 49yrds a no. Im good on the target at 49, but with a big ol buck....nah ill take 20yrds and light brush(right in front of him).