Matt Workman Previs Tools: Camera Tools v2.0 Maya MEL Intro
Get the Script/Plug-In at my blog:
http://www.mattworkman.com/2014/01/04...
This script was created to automate creating cameras in Maya with real world attributes. You can create the camera from viewport, enter the focal length, and several other helpful functions for your virtual cinematography.
Cheers,
Matt