ZEISS Stemi 355 Stereo Microscope

Overview

The ZEISS Stemi 355 is a high-performance Greenough-style stereo microscope engineered for precision visual inspection, documentation, and routine analysis in research laboratories, quality control environments, and industrial manufacturing settings. Unlike conventional Common Main Objective (CMO) designs, the Stemi 355 employs dual, laterally separated optical paths—each with its own objective lens—to deliver true stereoscopic depth perception, natural spatial orientation, and minimal image distortion across the entire zoom range. Its 5.5:1 continuous zoom optics provide seamless magnification from 7.2× to 40×, extendable to 200× using optional widefield eyepieces (e.g., 25×) and auxiliary objectives (e.g., 2×). The system’s mechanical zoom calibration ensures repeatable magnification settings without reliance on digital readouts—a critical advantage in GLP-compliant workflows where traceability and operator independence are essential.

Key Features

• Greenough optical architecture delivering inherent 3D visualization, high contrast, and excellent edge definition under both reflected and transmitted illumination
• Integrated multi-mode LED illumination system supporting near-vertical incident light, dual-side oblique reflected light, ring light, transmitted light, and hybrid illumination configurations—enabling optimal contrast for diverse sample topographies
• Extended working distance of up to 185 mm, facilitating manipulation of large or bulky specimens (e.g., PCB assemblies, battery cells, or geological samples) beneath the objective
• Maximum field of view diameter of 64 mm at lowest magnification—ideal for rapid scanning of macroscopic features prior to targeted high-magnification examination
• Optimized optical resolution of 489 line pairs per millimeter (lp/mm) at maximum usable magnification, supported by an effective numerical aperture of 0.082
• Compact, modular stand design compatible with Stand C (basic column mount) and Stand L (motorized, programmable illumination memory)—the latter supports user-defined illumination presets for standardized SOP execution

Sample Compatibility & Compliance

The Stemi 355 accommodates a broad spectrum of non-destructive, macro-to-micro scale specimens—from intact printed circuit boards and lithium-ion battery pouch cells to biological specimens such as insect exoskeletons, plant tissue sections, and forensic trace evidence. Its long working distance and flexible illumination options eliminate shadowing artifacts common in high-NA compound microscopy, making it especially suitable for low-contrast, reflective, or highly textured surfaces. The instrument complies with IEC 61000-6-3 (EMC emission standards) and IEC 61000-6-2 (immunity), and its LED illumination meets ISO 15223-1 requirements for medical device labeling. When paired with ZEISS ZEN software and configured with audit-trail-enabled hardware, the system supports 21 CFR Part 11 compliance for regulated life science and pharmaceutical applications.

Software & Data Management

While the Stemi 355 operates independently as an optical instrument, it is fully compatible with ZEISS ZEN Core and ZEN lite software platforms for image acquisition, annotation, measurement (length, angle, area, particle count), and report generation. Live video streaming, time-lapse capture, and multi-focus stacking (via motorized Z-drive integration) are supported. All metadata—including magnification, illumination mode, exposure parameters, and timestamp—are embedded in TIFF and JPEG outputs. For laboratory information management systems (LIMS) integration, ZEN provides configurable export protocols (CSV, XML, DICOM-SR) and supports HL7 message formatting where required for clinical pathology workflows.

Applications

• Electronics manufacturing: Visual inspection of solder joints, wire bonding integrity, and PCB trace continuity under variable lighting angles
• Automotive QA: Fracture surface analysis of cast components, weld seam evaluation, and dimensional verification of precision-machined parts
• Energy storage R&D: Non-invasive assessment of electrode coating uniformity, separator integrity, and dendrite morphology in Li-ion cells
• Life sciences education: Classroom dissection support, parasite identification (e.g., nematodes, cestodes), and live specimen observation without immersion media
• Geosciences and paleontology: Stereoscopic documentation of fossil morphology, mineral grain boundary mapping, and thin-section orientation alignment
• Forensic casework: Toolmark comparison, fiber morphology analysis, and gunshot residue pattern documentation under polarized or darkfield-enhanced illumination

FAQ

Does the Stemi 355 support digital camera integration?
Yes—it features a standardized C-mount port (1× or 0.5× relay lens options) compatible with monochrome and color CMOS/CCD cameras from ZEISS and third-party vendors.
Is the illumination intensity adjustable?
Yes—continuous dimming control is available via front-panel rotary encoder or ZEN software interface, with intensity logging enabled in audit-trail mode.
Can the Stemi 355 be used for photomicrography in regulated environments?
When deployed with ZEN software configured for electronic signatures and audit trail, and operated under documented SOPs, it fulfills data integrity requirements per ALCOA+ principles and supports FDA inspection readiness.
What is the warranty coverage for the Stemi 355 in North America and EMEA?
ZEISS provides a standard 24-month limited warranty covering parts and labor; extended service plans (including preventive maintenance and calibration certification) are available through authorized ZEISS Service Centers.
Are ergonomic accessories such as tilting binocular tubes or footswitches available?
Yes—ZEISS offers ergo stands, adjustable viewing tubes (incl. 0–30° inclination), and foot-operated focus/capture switches to reduce repetitive strain during extended use sessions.