[nis]

Hm  can you briefly explain why you want to use a 24-70 on Aps-C?

16-85 will indeed put my FL in one lens, but I found out that IQ more or less is the same with my current lens at the cost of $200++, I don't think it worth it

 

I want to choose 24-70 since this FL is my shooting range, as stated on my original post, and yes.. I don't want to buy Nikon's well known 24-70, I will go maybe either Tamron/Sigma **budget limitation**

 

17-55 will lose so much of my shooting range (55~70) which is may come in handy if I can't move forward quickly enough to take the shoot

 

another question though:

 

how big is the differences of focus speed and accuracy between 18-105 and Tamron 24-70/Sigma 24-70/Nikkor 24-70...

 

for me focus accuracy and speed is critical..

 

Thanks

Nis