The native camera settings in Maya allow the creation of Perspective and Orthogonal cameras. However, Redshift also supports Fisheye, Spherical, Cylindrical and Stereo Spherical cameras.
To create those types of cameras in Maya, you modify the Redshift 'Camera Type' attribute on the camera as shown below.
Go to the camera's Redshift attributes and use the Camera Type attribute to turn the camera into a Fisheye, Spherical, Cylindrical or Stereo Spherical camera