The understanding of our surroundings has often been limited by the instruments with which we can measure things. Over time, humanity has vastly improved the skills of controlling beams of the smallest particles - be it photons, electrons, or ions - to increasingly zoom into and measure the objects that surround us. Atom probe tomography, having no strict beams, nonetheless results with million times magnifications and spatially resolves isotopes within materials in 3-dimensions. I will show how the technique, and its progenitor Field Ion Microscopy, achieves this feat and discuss its application to measuring various types of materials including metal alloys and glasses, semiconductors, and minerals. Methods to measure more dynamic (or softer) materials will also be discussed, along with conferring the benefits and limitations of the characterization technique.