"Journey to the Microcosmos: What Microscope Do We Use?" explains how microscopic organisms are collected, cared for, and filmed for scientific observation. The video introduces core microbiology and microscopy concepts, including algae, ciliates, flagellates, slides, coverslips, magnification, depth of field, polarized light, transparency, pigments, and cell stains. It also describes how sample preparation affects what can be seen, why microbes often appear two-dimensional or transparent, and how real-time versus sped-up footage is identified. With clear behind-the-scenes explanations of microscope equipment, optics, and observation methods, this episode supports life science and laboratory science topics commonly taught in school curricula, especially scientific inquiry, cell observation, and the use of tools to investigate the microscopic world. Part of the "Journey to the Microcosmos" series.