We consider the notion of finite dimensional reconstructions systems (RS's), which includes the fusion frames as projective RS's. We study erasures, some geometrical properties of these spaces, the spectral picture of the set of all dual systems of a fixed RS, the spectral picture of the set of RS operators for the projective systems with fixed weights and the structure of the minimizers of the joint potential in this setting. WeIn the case J = {j}, the lower bound in Theorem 3.3 is greater than that obtained in [3]:Proposition 3.4. Let V, and M J be as in Theorem 3.3, with J = {j}. ThenProof. We can suppose M −1 J ≥ 1, since otherwise (7) is evident. Note that1. The vector µ ∈ Λ(D(V)).1. The set Λ(OP v ) is convex.