For Elk it's always a tough call. but they are VERY stupid animals and I would bet that they are nearly blind. I will draw when the shot is within 90 sec. I draw straight back and belive me you will have the gusto to do it if you practice. Be ready to release as soon as you see the hair that you want to hit.

Keep your call in your mouth and give a soft mew AS you shoot- If you wait until after you mew he may bolt- as he realizes that you are right on top of him.

Deer ? Your guess is as good as mine. They seem to have much better vision and I've never bow hunted them.