I have a Canon Rebel.I have decided to invest in lens versus investing in a new camera. Will the Kelly Lens do for an Alaska trip? I know I will need a good zoom lens...but don't want to be changing lens...just want a good all around lens with a good zoom. Currently my stock Canon 18-55 lens is not doing me any good. Can anyone suggest a good all around lens for me. I've found that I use the zoom a lot more than wide angle. Someone pointed me to the Tamron 18-250. Can someone tell me the difference besides the huge price difference?