  A new definition of "Realism" is proposed: it is that a gedanken
"spectrograph" of hidden variables behaves as an actual (say, wavelength)
spectrograph. The question is: does this definition allow, by itself, the
derivation of Bell's inequalities? If it were, then such a spectrograph would
be impossible, for Bell's inequalities are observed to be violated. In this
short paper it is reported that, on the contrary, such spectrograph is
compatible with the violation of Bell's inequalities. This result puts some new
light on the controversy about the hypotheses necessary to derive Bell's
inequalities. In particular, "Spectrograph's Realism", and "Locality", are
proven to be different, and both necessary, hypotheses to derive Bell's
inequalities.
