Mitutoyo M Plan Apo 20x Objective (NA 0.42, WD 20mm, Infinity, M26)
Regular price
$2,350.00
The Mitutoyo M Plan Apo 20× Objective is a plan apochromat objective from Mitutoyo’s M Plan Apo series — delivering 20× magnification with an exceptional 20mm working distance and plan apochromat correction optimized for visible light. The apochromatic optical design provides a flat, chromatic-aberration-free image for accurate color rendering, making this objective an ideal choice for metallurgical examination, semiconductor inspection, and any industrial application requiring true-color imaging at intermediate magnification with extended working clearance.
KEY FEATURES
- Long working distance: 20mm — exceptional clearance for a 20× objective, providing ample room for specimens in environmental chambers, cryostats, vacuum systems, industrial fixtures, and laser processing setups where standard objectives cannot reach
- NA 0.42, 0.7µm resolving power — practical numerical aperture for a long working distance 20× objective, delivering sub-micron resolution for detailed surface inspection, grain structure analysis, and feature measurement
- Plan apochromat (M Plan Apo) correction — Mitutoyo’s highest level of chromatic and spherical aberration correction for accurate, flat-field imaging with true color rendering across the full visible spectrum — essential for metallographic examination and color-based defect analysis
- 1.2mm field of view (×24 eyepiece) — practical field coverage for intermediate-magnification survey and inspection, bridging the gap between wide-area 5×/10× overview and high-magnification 50×/100× detail
- Visible light optimized — the standard visible-light version of the M Plan Apo 20×; for NIR/SWIR applications, see the M Plan Apo NIR 20× (378-824-16)
- Infinity-corrected, M26 thread — compatible with Mitutoyo FS series microscopes and other infinity-corrected systems with M26 nosepieces
- 🇯🇵 Mitutoyo quality, made in Japan — precision optical construction for consistent, high-efficiency visible light transmission and long service life
- Catalog number 378-804-3
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Technical Specifications
| Catalog Number | 378-804-3 |
| Magnification | 20× |
| Numerical Aperture (NA) | 0.42 |
| Immersion Medium | Dry (air) |
| Working Distance | 20mm (Long Working Distance) |
| Spectral Range | Visible light |
| Resolving Power | 0.7µm |
| Focal Depth | 1.6µm |
| Focal Length | 10mm |
| Field of View (Ø24 eyepiece) | Ø1.2mm |
| Real FOV (1/2" chip camera) | 0.24 × 0.32mm |
| Optical Design | M Plan Apo (Plan Apochromat, visible light) |
| Correction | Infinity-corrected (brightfield) |
| Thread / Mount | M26 |
| Compatible Systems | Mitutoyo FS series; other infinity-corrected M26 systems |
| Country of Origin | Japan |
| SKU | 378-804-3 |
Microscope Compatibility
Typical Applications
Metallographic examination of grain structure, phase identification, and surface condition at 20×
Semiconductor and IC surface inspection at intermediate magnification
Defect analysis and documentation on polished surfaces, thin films, and coatings
Intermediate-magnification imaging in environmental chambers, cryostats, or vacuum systems
Inspection of specimens in industrial fixtures requiring 20mm working clearance
Intermediate step in a multi-magnification M Plan Apo workflow (10× → 20× → 50× → 100×)
