(KL Series) SCHOTT 157.040 “Mini” Annular Ringlight — 40mm

The SCHOTT 157.040 is a compact “Mini” annular ringlight designed to provide a continuous, 360° ring of illumination around smaller microscope objectives for shadow-minimized lighting in precision inspection and microscopy. It mounts directly to the objective via a thumb screw and is intended for 40 mm standard objectives.

Accessory note: This is a fiber-optic ringlight (light guide). It does not generate light by itself and must be connected to a compatible SCHOTT KL-series light source.

Specifications:

Manufacturer: SCHOTT
Part number / SKU: 157.040
Type: “Mini” annular ringlight (fiber-optic ring illumination)
Ringlight inner Ø: 40 mm (1.57")
Best-fit objective size: 40 mm standard objectives
Use case: Uniform, shadow-reducing illumination in compact microscope/inspection setups
Compatibility: SCHOTT KL-series fiber optic light sources (see below)

Why choose the “Mini” ringlight?

In tight work envelopes, a smaller ringlight can be the difference between a clean, repeatable setup and a station that constantly gets bumped or re-aimed. The 157.040 is designed for compact objectives and fixtures where clearance and access matter.

Clearance: better fit for compact objectives and tight fixtures
Uniformity: annular geometry supports consistent lighting across the field
Repeatability: reduces “operator aiming” variability vs gooseneck guides

Common System Pairing

This ringlight is part of the SCHOTT KL Series. A common pairing in your catalog is:

About the Manufacturer:

SCHOTT is a multinational technology group known for specialty glass, advanced materials, and precision optical components used across microscopy, industrial inspection, electronics, and life-science workflows. SCHOTT’s KL illumination ecosystem is built around modular light guides and accessories designed to standardize illumination geometry and improve repeatability in inspection and imaging setups. ([soscleanroom.com](https://www.soscleanroom.com/product/illuminators/kl-series-schott-157-040-mini-ringlight-40mm/))

Related Ringlights (Size-Up Options)

If your objective diameter is larger, consider the matching “Standard” ringlight sizes:

SCHOTT 157.410 “Standard” Ringlight 58mm
SCHOTT 157.420 “Standard” Ringlight 66mm
SCHOTT A08600 Universal Ringlight (47–62 mm range)

Notes: The fastest way to pick the right ringlight is: (1) objective diameter, (2) working distance/clearance, then (3) uniformity vs directional contrast needs.

For application support, call 800-443-7101 or email Sales@SOSsupply.com.

Product page updated: Feb. 5, 2026 (SOS Technical Staff)

© 2026 SOSCleanroom.com. All rights reserved.

The Technical Vault: SCHOTT 157.040 “Mini” Annular Ringlight (40mm)

Vault purpose: How mini annular illumination changes defect visibility, what “size match” really means, and how to lock down geometry so inspection results stay repeatable.

1) What the 157.040 is

The SCHOTT 157.040 is a compact (“Mini”) fiber-optic annular ringlight intended for 40 mm standard objectives. It delivers a continuous 360° ring of illumination around the viewing axis to reduce harsh directional shadowing in microscopy and precision inspection.

2) Annular illumination: when it helps (and when it doesn’t)

Ring illumination is typically chosen when you need uniformity and repeatability. It can reduce the inspection drift that happens when operators constantly re-aim goosenecks.

Best for: uniform cosmetic inspection, exposure stability in camera systems, reducing harsh shadows
Consider alternatives: if you need aggressive directional lighting to “pop” texture, scratches, or tool marks

3) What “40mm objective” match means

The most important fit parameter is the front-end objective diameter and the mechanical clearance around it. If the inner diameter is too small, you’ll get interference; if it’s too large, the ring may not center reliably and illumination can become non-uniform.

Selection shortcut: match objective diameter first, then validate clearance and working distance with your fixture stack.

4) What to document for repeatability

Ring position: mark axial placement so it resets the same after cleaning
Intensity setpoint: record the light source output setting
Working distance: record objective-to-part distance at focus
Reference image: keep a “golden” exposure/contrast example for baseline

5) KL Series pairing (what it connects to)

The 157.040 is part of the SCHOTT KL Series illumination ecosystem and must be used with a compatible light source. Common pairings in your catalog include:

6) Related sizes (when to size up)

If your objective is larger than 40 mm, size up to the matching “Standard” ringlight family:

7) Source basis (spec traceability)

SOSCleanroom listing: SCHOTT 157.040 product page (SKU, ringlight size designation, and KL Series context). ([soscleanroom.com](https://www.soscleanroom.com/product/illuminators/kl-series-schott-157-040-mini-ringlight-40mm/))
Related items (cross-links verified): 157.410, 157.420, A08600, KL 1600 LED, KL 300 LED. ([soscleanroom.com](https://www.soscleanroom.com/product/illuminators/kl-series-schott-157-410-standard-ringlight-58mm/))