[swibco79]

Just got few questions
1. How come the factory lens is a lot more expensive than the other one even with the same range of focus? Besides all those technology just as IS or USM (from Canon), are these two lens have much different in pics?

2. I heard someone says that the longer the range it is, the worser the quality it is (e.g. 28-300 may not be as good as 100-300mm) , is that true and why?

Thanks

[kliss]

1. How come the factory lens is a lot more expensive than the other one even with the same range of focus? Besides all those technology just as IS or USM (from Canon), are these two lens have much different in pics?
a. Quality and durability
b. IS enables lower shutter speed; USM for shorter focusing time; both of them cannot compare.
Some IS lens do provide a little bit poor in picture quality comparing to non-IS version, such as 70-200 vs 70-200 IS

2. I heard someone says that the longer the range it is, the worser the quality it is (e.g. 28-300 may not be as good as 100-300mm) , is that true and why?
Yes, it is true. That is why the prime lens is the best in picture quality because it does not zoom totally.