I use a small inexpensive range finder that measures up to 50 yards. I only paid about $30 for it and it works fine. I use it when I set up in a new spot and identify some land marks such as trees, rocks ect. I found it very helpful this past year when I hunted a gully area. I shot a deer that was standing at 28 yards from me, however, it sure looked like it was 35 yards because it was across the gully. When my friend helped me track it, he thought that the shot was around 40 yards. It was very deceptive. I'm glad that I trusted the range finder and not my own judgement, which I consider pretty good.