ISO 8578:2012

Overview

ISO 8578:2012 - Microscopes - Marking of objectives and eyepieces specifies standardized formats and placement for optical data and symbols on microscope objectives and eyepieces. The standard ensures that essential information (magnification, numerical aperture, tube length, cover-glass thickness, immersion medium, field number, chromatic/field correction, etc.) is marked clearly and consistently to enable correct use, selection and servicing of microscope optics.

Key topics and requirements

• Mandatory objective markings: Includes magnification and numerical aperture (e.g., 100/1.30), tube length or infinity symbol (e.g., 160 or ∞), cover-glass thickness (e.g., /0.17, /0 or /0.14-0.20 for correction collars), objective field number (OFN), chromatic correction (FL/APO), flatness (PLAN), phase contrast (PH), and manufacturer ID.
• Mandatory eyepiece markings: Visual magnification and field-of-view number separated by a slash (e.g., 10×/18) plus manufacturer identification.
• Recommended additional markings: Optional items such as colour-coded rings for magnification and immersion media, phase/contrast color coding, DIC, epi-illumination symbols, correction collars, long working distance (L, LD, LWD), and country of manufacture.
• Colour coding guidance: The standard recommends specific colours for magnification rings and immersion-media rings to aid quick identification; when an immersion ring is used it should be combined with a magnification ring and placed closer to the front lens.
• Arrangement and positioning: A recommended order of marking groups (columns A → B → C) to maintain consistency and readability across objectives.
• Examples and format rules: Specific formatting examples (e.g., ∞/0.17, OFN25, PH 2) are provided to guide manufacturers.

Applications and users

ISO 8578:2012 is used by:

• Microscope manufacturers for labelling objectives and eyepieces to meet market and regulatory expectations.
• Quality assurance and technical documentation teams to create consistent product markings and user manuals.
• Laboratory managers and procurement to verify compatibility (tube length, cover-glass correction, immersion medium).
• Service, calibration and repair technicians for correct identification during maintenance and replacement.
• Standards and regulatory bodies reviewing optical conformity.

Practical benefits include reduced user error, faster objective selection, improved interoperability of optical components, and clearer maintenance records.

Related standards

• ISO 8036 - Immersion liquids for light microscopy
• ISO 19012‑1 - Designation of microscope objectives - Part 1: Flatness of field / Plan
• ISO 19012‑2 - Designation of microscope objectives - Part 2: Chromatic correction

Keywords: ISO 8578:2012, microscopes, marking of objectives and eyepieces, objective markings, eyepiece markings, colour coding, numerical aperture, magnification, immersion media.