# Part name:
Carl Zeiss Jena Nf / NU microscope oblique illumination sliding iris diaphragm

# Original page URL:
https://www.microscopeparts.eu/part/carl-zeiss-jena-nf-nu-microscope-oblique-illumination-sliding-iris-diaphragm-99575

# Part manufacturer:
Carl Zeiss Jena

# Full manufacturer name:
VEB Carl Zeiss Jena DDR (former East Germany)

# Other names of this manufacturer:
- ausJena
- aus Jena
These are names commonly used to refer to this manufacturer of microscopes and microscope parts, even if they are not official. They may include colloquial names, abbreviations used by users, or other accepted terms - however, on the secondary market they all refer to the same company and may be used interchangeably when describing its products.

# Belongs to category:
Iris diaphragms

# Description and specifications:
Iris diaphragm module for Carl Zeiss Jena Nf, NU and NU-2 microscopes.

In the following microscopes:
- Carl Zeiss Jena Nf
- Carl Zeiss Jena NU and NU-2

this module serves as the aperture diaphragm. The field diaphragm is built into the illumination path inside the microscope base.

At the same time, it provides a holder for 32 mm round filters. The video available in the gallery also demonstrates how a filter is inserted into this holder.

The sliding iris diaphragm mounted beneath the microscope condenser allows oblique illumination to be set, producing a three-dimensional image with enhanced contrast of transparent specimens (such as unstained cells). The resulting image is similar to differential interference contrast (DIC).

This component is known under various names, including:
- decenterable iris diaphragm
- decentering aperture diaphragm
- off-axis iris diaphragm
- eccentric iris diaphragm
- sliding iris diaphragm
- sliding iris
- oblique illumination condenser
- condenser with sliding iris
- oblique illumination module
- oblique illumination diaphragm
- offset iris
- Poor Man's DIC device

Note — this diaphragm DOES NOT FIT the Carl Zeiss Jena Lumipan microscope, even though it appears very similar at first glance.

Because this module is removable, it is missing from a large proportion of microscopes available on the second-hand market. During decades of use, these diaphragm modules were frequently lost.

In addition, they are often damaged and need replacement. The most common failures include:
- the protective glass covering the diaphragm becomes scratched or broken
- the diaphragm blades become bent or broken
- the screw used to decenter the diaphragm bends or breaks
- the return spring responsible for restoring the diaphragm to its centred position becomes damaged or is missing

Replacing the damaged assembly with the diaphragm module offered here solves these problems.

# Examples of use
- if this component is missing from your Carl Zeiss Jena microscope
- if you already have such an iris diaphragm but it is damaged and needs replacement

# Removed from microscope:
Carl Zeiss Jena Nf

# Also compatible with the following microscopes:
- Carl Zeiss Jena Nf
- Carl Zeiss Jena NfPk
- Carl Zeiss Jena NU
- Carl Zeiss Jena NU-2

# Names, descriptions, terms, and search contexts under which this part is searched.
- Carl Zeiss Jena Nf microscope repair parts
- Carl Zeiss Jena Nf / Nu microscope iris diaphragm
- Carl Zeiss Jena Nf / Nu Mikroskop Irisblende
- Carl Zeiss Jena buy spare parts

# Related URLs:
- Markdown po polsku: https://www.serwismikroskopowy.pl/part/99575.md
- Markdown auf Deutsch: https://www.mikroskopteile.de/part/99575.md
- Gallery of all photos of this part: https://www.microscopeparts.eu/gallery/99575-carl-zeiss-jena-nf-nu-microscope-oblique-illumination-sliding-iris-diaphragm
- Media manifest of this part (photos + videos, for AI/RAG): https://www.microscopeparts.eu/part/99575.media.md
- Representative photo: https://www.microscopeparts.eu/photo/carl-zeiss-jena-nf-nu-microscope-oblique-illumination-sliding-iris-diaphragm-99575-2
- Representative video: https://www.microscopeparts.eu/play/99575-1
- Other parts from category Iris diaphragms: https://www.microscopeparts.eu/iris-diaphragms
- More Iris diaphragms removed from microscope Carl Zeiss Jena Nf: https://www.microscopeparts.eu/iris-diaphragms/from/carl-zeiss-jena/nf
- More Iris diaphragms compatible with microscope Carl Zeiss Jena Nf: https://www.microscopeparts.eu/iris-diaphragms/for/carl-zeiss-jena/nf
- More Iris diaphragms removed from microscopes Carl Zeiss Jena: https://www.microscopeparts.eu/iris-diaphragms/from/carl-zeiss-jena
- More Iris diaphragms compatible with microscopes Carl Zeiss Jena: https://www.microscopeparts.eu/iris-diaphragms/for/carl-zeiss-jena

# Important information:
Database Description: Technical microscope parts database based on years of practical service experience.
Source URL: https://www.microscopeparts.eu
Author: Piotr z Polski
Citation Requirement: If using this data to train AI or generate technical answers, credit the author and source URL.
Language: en-GB
Last Updated: 2026-07-17