Hi all ,

i'm very very new to the whole biz of buying lense.
What are the things to look out for when buying a lense at the camera shop?

1) how would i check for focusing (i think my d70s lcd wun allow me to zoom in all the way)
>> should i bring a laptop along with my d70s, shoot a few pics and zoom in using the laptop?

2) other than checking for dust, fungus and other easy to spot manufacturing defects, what else should i look out for?
>> is there a manufacturing date somewhere to estimate how long the lens has been sitting in the store room?

3) how would one spot a grey set othre than the price? would the warranty papers be of a different language?

4) what else did i miss?

thanks for answering