ISO 19012-2:2013

Microscopes - Designation of microscope objectives - Part 2: Chromatic correction

ISO 19012-2:2013 specifies classes of chromatic correction and defines minimum requirements regarding chromatic correction. The defined marking on the component enables the operator to correctly use the microscope. The standard application for visual observation refers to the combination of objective and tube lens as specified by the manufacturer. The specifications regarding chromatic correction only refer to axial chromatic aberration.

Microscopes — Désignation des objectifs de microscope — Partie 2: Correction chromatique

General Information

• Status: Published
• Publication Date: 05-Feb-2013
• ICS: 37.020 - Optical equipment
• Technical Committee: ISO/TC 172/SC 5 - Microscopes and endoscopes
• Drafting Committee: ISO/TC 172/SC 5/WG 9 - Optical performance of microscope components
• Current Stage: 9093 - International Standard confirmed
• Start Date: 13-Mar-2024
• Completion Date: 13-Dec-2025

Relations

• Revises: ISO 19012-2:2009 - Optics and photonics - Designation of microscope objectives - Part 2: Chromatic correction
• Effective Date: 07-Apr-2012

Overview

ISO 19012-2:2013 - "Microscopes - Designation of microscope objectives - Part 2: Chromatic correction" defines classes and minimum requirements for chromatic correction of microscope objectives. The standard standardizes how manufacturers mark objectives (achromat, semiapochromat, apochromat) and sets measurable criteria for axial chromatic aberration so operators can select and use objectives correctly. It applies to visual observation using the objective in the combination with the manufacturer‑specified tube lens and addresses only axial chromatic aberration (focus differences between wavelengths).

Key topics and technical requirements

• Scope: Classification and marking for chromatic correction of microscope objectives; applies to visual observation and objective + tube lens combinations.
• Chromatic classes:
  • Achromat (optional marking: ACH, ACHRO, ACHROMAT)
  • Semiapochromat (mandatory marking options: SEMIAPO, FL, or names containing “FLU”)
  • Apochromat (marking: APO)
• Wavelength references: reference (e‑line) = 546.07 nm; blue (F′‑line) = 479.99 nm; red (C′‑line) = 643.85 nm.
• Depth of field (δ): Basic criterion given by the formula δ = n·λ / (2·NA_ob^2) where n = refractive index in object space, NA_ob = objective numerical aperture, λ = reference wavelength (0.54607 µm). Annex A tabulates δ for typical NA values.
• Focus difference limits (axial chromatic aberration):
  • Achromat: |focus_red − focus_blue| ≤ 2 × δ
  • Semiapochromat: |focus_red − focus_reference| and |focus_blue − focus_reference| ≤ 2.5 × δ
  • Apochromat: those focus differences ≤ δ
• Marking rules: Specific label formats are allowed to ensure consistent user information; objectives sold before 2011 are exempt from some markings.

Applications and users

ISO 19012-2 is practical for:

• Microscope manufacturers and optical designers - to design, test and label objectives consistently.
• Quality assurance and metrology labs - to validate chromatic performance against standardized limits.
• Laboratory managers, clinical and research microscopists - to select objectives with known chromatic correction for imaging or visual inspection tasks.
• Procurement and standards bodies - to specify objective performance in tenders and conformity assessments.

Adopting ISO 19012-2 helps ensure predictable color focus behavior, improves reproducibility of observations, and simplifies objective selection and traceability.

Related standards

• ISO 19012-1 (Flatness of field / Plan)
• ISO 10934-1 (Vocabulary for microscopy - Part 1: Light microscopy)
• ISO 8578 (Marking of objectives and eyepieces)

Keywords: ISO 19012-2:2013, microscope objectives, chromatic correction, axial chromatic aberration, achromat, semiapochromat, apochromat, depth of field, numerical aperture, objective marking.

Standards Content (Sample)

INTERNATIONAL ISO
STANDARD 19012-2
Second edition
2013-02-01
Microscopes — Designation of
microscope objectives —
Part 2:
Chromatic correction
Microscopes — Désignation des objectifs de microscope —
Partie 2: Correction chromatique
Reference number
©
ISO 2013
© ISO 2013
All rights reserved. Unless otherwise specified, no part of this publication may be reproduced or utilized otherwise in any form
or by any means, electronic or mechanical, including photocopying, or posting on the internet or an intranet, without prior
written permission. Permission can be requested from either ISO at the address below or ISO’s member body in the country of
the requester.
ISO copyright office
Case postale 56 • CH-1211 Geneva 20
Tel. + 41 22 749 01 11
Fax + 41 22 749 09 47
E-mail [e-mail]
Web www.iso.org
Published in Switzerland
ii © ISO 2013 – All rights reserved

Contents Page
Foreword .iv
1 Scope . 1
2 Normative references . 1
3 Terms and definitions . 1
4 Requirements . 2
4.1 Basic criterion for the depth of field. 2
4.2 Markings . 2
4.3 Specifications. 2
Annex A (informative) Depth of field, δ . 4
ob
Bibliography . 5
Foreword
ISO (the International Organization for Standardization) is a worldwide federation of national standards
bodies (ISO member bodies). The work of preparing International Standards is normally carried out
through ISO technical committees. Each member body interested in a subject for which a technical
committee has been established has the right to be represented on that committee. International
organizations, governmental and non-governmental, in liaison with ISO, also take part in the work.
ISO collaborates closely with the International Electrotechnical Commission (IEC) on all matters of
electrotechnical standardization.
International Standards are drafted in accordance with the rules given in the ISO/IEC Directives, Part 2.
The main task of technical committees is to prepare International Standards. Draft International
Standards adopted by the technical committees are circulated to the member bodies for voting.
Publication as an International Standard requires approval by at least 75 % of the member bodies
casting a vote.
Attention is drawn to the possibility that some of the elements of this document may be the subject of
patent rights. ISO shall not be held responsible for identifying any or all such patent rights.
ISO 19012-2 was prepared by Technical Committee ISO/TC 172, Optics and photonics
...