I am wondering which of my 2 sigma lenses to take on safari.. They are both older ones, analog but I havent saved enought yet for my first digital SLR. So I have either a Sigma APO zoom macro 70 - 300 f4-5.6 or a sigma 28- 200 zoom f 3.8-5.6 I really dont know which is the better quality lense since i inherited this camera kit.. Any help would be great or tips on how to know a good quality lense when you see it. Thanks!!!