i have this scope on my knight disc. It has always been clear except one time. This year at dusc it was as foggy as it gets and i couldent see the deer in the scope. I was ready to shoot at 120 yards and couldent see it. It eventually got 10 yards from me and i couldent see it, but it doesent bother me because they were very bad conditions, other then that it has been perfect. Shot one deer right before dark this year and it was clear and killed 6 others with that on the big disc