Difference between cameras (raw)?

[JackH]

@Jossie

I would say, since each profile is only an approximation of the transformation from the device dependent colour space to the device independent colour space. The accuracy of the transform depends mainly on two things: number of patched used, mathematical algorithm used to derive the transformation.

And most important of all, SSF shapes: if they were the same as physiological cone fundamental responses we may not need a transform at all, see for instance here. As it is, matrix definition is an overdetermined problem with an infinite number of solutions, so the best we can do is choose one based on reasonable criteria.