[PatrickCHO]

我只是一名新手。現處於兩難之間，都怪自己錢包不夠，
要事事計算清楚。我想請教各路前輩，這兩支枝鏡除了價格外的分別(因為$4500內都是本人預算)，它們的成象、操作等，那枝優勝。
特別想知道的是.........
要恆定大光圈-------Sigma 18-50 2.8ex.............還是
IS USM 高速對焦與防手震....

所以，我掙扎於成像 與大光圈/IS 之間，
盼望有心人多多指點!!
先謝謝你們.................^^

[apexi66]

Hi,
I used Sigma 18-50 2.8 EX before and now I change to 17-85 IS USM.
I prefer 17-85 for the following reson:
1. Zoom range - more flexible
2. IS - very good in dim condition
3. Fast and slient focus

18-50 a bit slow and more noise and also the coating of the body easy to get scratch and peel off.

This is my personal opinion only, if you get a chance, you should try both and then decide.