[timhbf]

I want to buy this combo but I've following questions:

1) What's the actual range of Tamron a16 to be used in 400d? 18-50mm or x 1.6?
2) What value of the len can make 1:1 to human eyes? I tried 400d with Kit ken, when it uses 55mm, the size of the object in view finder almost the same as per my eyes, may be still a little bit smaller.
3) What's "L" and "DO" stands for canon lenes?
4) Typical in what shutter speed can make a clean image of a people who is walking in normal speed?
5) Does Tamron a16 made of metal or plastic just like the kit len does?
6) How to tell if the len is for aps-c or ff?

too many questions.......thanks for help!

[Philippe]

1)18-50 x 1.6, ie 28.8-80
2)1:4.5,比kit lens 的1:3.6更差
3)L即係頂級鏡,DO用了高折射鏡片
4)要視乎目標物離你有多近,越近要越快
5)好似係膠鏡身,不過係金屬mount
6)APS only

[pongyee]

補充：

(3) DO 是為數碼特性而設的折射鏡
(4) 個人是對著你行還是橫行？