The Collaborative International Dictionary of English v.0.48:

Photometry \Pho*tom"e*try\, n. [Cf. F. photom['e]trie.]
   That branch of science which treats of the measurement of the
   intensity of light.
   [1913 Webster]

WordNet (r) 3.0 (2006):

photometry
    n 1: measurement of the properties of light (especially luminous
         intensity)

Moby Thesaurus II by Grady Ward, 1.0:

37 Moby Thesaurus words for "photometry":
   actinology, actinometry, aerial photography, aeroballistics,
   aerodynamics, aerogeology, aerography, aerology, aeromechanics,
   aeromedicine, aerometry, aeronautical meteorology, aerophotography,
   aerophysics, aeroscopy, aerospace research, aerostatics,
   aviation technology, avionics, catoptrics, climatology, dioptrics,
   geometrical optics, heliography, heliology, heliometry,
   hydrostatics, kinematics, kinetics, meteorology, optics, photics,
   photology, physical optics, pneumatics, rocketry, supersonics