Thanks. So basically a 6-18x50 is slightly more powerful than 4-12x50 but they both let the same amount of light in. I guess the 6-18 would be better for open field shots and 4-12 for more wooded shots, right? I have a friend who has a Swarovski 6-18x50 and says I need to get one, but I am trying to make sure that would be best for me. Thanks again.