Most of my stalking is in woodlands, shots never really going further than 120 yrds and I have never needed a range finder. Yesteday I stalked with a friend in Wiltshire, over the rolling plains and realised just how bad I am at range estimation.
It was almost a disastrous stalk on a large group of roe because I thought I was much closer than I actually was. The first shot going low and nicking the back of a front leg. Luckily a friend I was stalking with, and who is much more experienced at longer range work (and an extremely good shot) was watching from the other side of the valley and was able to make a very good shot almost straight away to rectify my mistake.
I'd forgotten just how bad you feel when things to wrong and what a muppet you can make of yourself. It was a good learning experience though and I won't be making that mistake again in a hurry. I won't be rushing out to buy a range finder, because I don't usually need one, but I will be spending more time working out what roe look like through my scope at 100 - 150 - 200 & 250 yards.