>By the way, I have a question for you. I am thinking to buy some
>filters. Apperantly, the filters made by Nikon are expansive. Therefore,
>I will try to find other brand names. In local store, I found Sigma and
>Quantary, how do you think about these filters? Whatelse will you
>recommand for reasonable quality and cheap filters? Thanks in advance.
>Zhihao Fei

The 24mm will vignette easily with thick-rimmed filters, especially if
you use a shade (use only Nikkor shade to avoid vignette). If you can find
Nikko filters, they are unusually thin. Nikkor filters just fit with the shade,
and Hoya filters may be OK without the shade. Most cheap filters are variable
in quality, and may have too-thick rims. I am not familiar with the Sigma
and Quantaray, but if the rims are thin enough, and the price low enough,
they may be OK (wide-angles are more forgiving with slight optical flaws
than teles). I generally recommend Hoya as a cheap alternative to Nikkors.