Light field representation is a model for three-dimensional (3D) image representation and integral imaging is an optical 3D imaging and representation method. A comparative investigation of light field representation and integral imaging is given in this paper. The practical integral imaging is shown to be equivalent to the discrete light field representation if some restrictions are imposed on the light field. On the other hand, it is shown that the integral imaging is not equivalent to the continuous light field representation. In any case, physical realisation of an arbitrary abstract light field representation may not be possible due to restrictions associated with the uncertainty principle related to the spatial and angular resolutions.