A novel apparatus and method for the quick and accurate determination of surface profile and depth reading within little or no mechanical motion is presented comprising a polychromatic light source; a means for focusing the light onto a point of sample target, said means having a known amount of longitudinal chromatic aberration; and a means for detecting the wavelengths of light reflected from the sample target. The light projected onto the sample target is focused according to wavelength due to the longitudinal chromatic aberration. While light from across the spectrum will be reflected, the light returning from the sample target will be most strongly reflected in a wavelength that is focused on a reflective point in the sample. The means for detecting the light in the present invention passes through a substantially pinhole aperture before the light is detected according to wavelength. The purpose of the pinhole aperture is resolution. The pinhole aperture ensures that those wavelengths that focus onto the pinhole are more strongly detected than wavelengths that do not focus on the aperture. Thus, the resolution of wavelength intensity peaks is greatly increased.