Use Maxwell Render's PyMaxwell tool to scan the camera's lens model

maxwell_lens_model.py

# Return the lens type name as a string
# Example: it = CmaxwellCameraIterator(); camera = it.first(scene); cameraLens = cameraParams.getLensType(); lens = mxa_lensTypeName(cameraLens)
def mxa_lensTypeName(cameraLens):
  lensTypeName = ''
  if cameraLens[0] == TYPE_CYLINDRICAL_LENS:
    lensTypeName = 'cylindrical'
  elif cameraLens[0] == TYPE_EXTENSION_LENS:
    lensTypeName = 'extension lens'
  elif cameraLens[0] == TYPE_FISHEYE_LENS:
    lensTypeName = 'fisheye'
  elif cameraLens[0] == TYPE_ORTHO_LENS:
    lensTypeName = 'ortho'
  elif cameraLens[0] == TYPE_PINHOLE_LENS:
    lensTypeName = 'pinhole'
  elif cameraLens[0] == TYPE_SPHERICAL_LENS:
    lensTypeName = 'spherical'
  elif cameraLens[0] == TYPE_THIN_LENS:
    lensTypeName = 'thin'

  return lensTypeName