In this tutorial Murohazzard show you how to export Maya camaras using the maya2Nuke python command. Personally, He find it better than the traditional FBX format export as it seems to be a bit buggy. 
Anyways, He 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)