An analysis of one dimensional adjacency effects is presented. This classical problem is shown to be amenable to closed form error analysis when 1D adjacency correction schemes are used. In particular the error made when surface reflectance is retrieved using an infinite target assumption is given in closed form. This allows deductions for the behavior of the error as a function of wavelength and optical thickness. Typical length scales of the adjacency effects are deduced and the range and magnitude of the error are also given in closed form.