The hollow structure connecting the objective lens to the eyepiece lens constitutes a critical component in optical instruments used for magnifying small objects. This element maintains the correct distance between these lenses, ensuring proper image formation and magnification. Its length is a key factor in determining the overall magnification power of the instrument.
This structural member plays a pivotal role in the accurate transmission of light within the instrument, contributing significantly to image quality. Its design and length have been standardized in many instruments to facilitate interchangeability of components and consistent performance. Historically, variations in its dimensions have influenced the development and evolution of these precision instruments.