In this tutorial I show you how to export Maya camaras using the maya2Nuke python command. Personally, I find it better than the traditional FBX format export as it seems to be a bit buggy.
Anyways, I hope you find this tutorial insightfil to you in some way. Here are the links to D/L the script:
the link for Maya2Nuke:
Note: Please read the instructions carefully on how to install the script in the maya folder (found in the creative crash D/L).