We design a system-level architecture for approaching the shot noise limit for passive triangulation of a quasi-monochromatic point source. Our emphasis is not in the novelty of the basic physics, but that existing systems lose fundamental information in the measurement pipeline. We preserve that information through maintaining analog signals combined with common-mode noise rejection in two successive levels of analog differentiation. We review the Cram´er-Rao bound of angle sensing as applied to the field of triangulation. We use a monolithic camera/balanced detector system for target location followed by precision triangulation. While we test many aspects of the system in various setups, of particular importance is the demonstration of nanometer-scale depth precision at 31 cm standoff having a baseline of 12.5 cm and a predicted shot noise uncertainty limit of 300 fm. While the results are still well above the shot noise limit, they represent several orders of magnitude improvement over current camera-only or other position-sensitive detector systems.