I also use the "Twilight" peep on my williams peep. It has an appeture of 0.125 and gives me good visibility in low light. In really low light, I do reserve the option of removing the peep and using the ghost ring. If you haven't tried it, you should. I can't tell much difference in my accuracy between the smaller appeture and the ghost ring out to 100 yards. You just naturally center the thing no matter how big the hole.