  Imaging technologies such as dynamic viewpoint generation are engineered for
incoherent radiation using the traditional light field, and for coherent
radiation using electromagnetic field theory. We present a model of coherent
image formation that strikes a balance between the utility of the light field
and the comprehensive predictive power of Maxwell's equations. We synthesize
research in optics and signal processing to formulate, capture, and form images
from quasi light fields, which extend the light field from incoherent to
coherent radiation. Our coherent cameras generalize the classic beamforming
algorithm in sensor array processing, and invite further research on
alternative notions of image formation.
