Nikon lens explained
 

A lot of people that are using the 5DmkII for filming have choose to couple it with nikon lenses. Reading through the posts I've found quite a few misconceptions regarding them.
On this page you can find a lot of valuable information for nikon lenses, especially their lettering designation:
Nikkor Lens Technology

On the site KenRockwell.com there also many interesting photographic topics, some very useful for cinematographers as well.