Inframet Visible Light Target
| Brand | Inframet |
|---|---|
| Origin | Poland |
| Model | Visible Light Target |
| Target Type | Transmission-type USAF 1951 Resolution Target |
| Pattern | 3-Bar Group |
| Group Numbers | 0–7 (optional 0–8) |
| Spatial Frequency Range | 1–228 lp/mm (optional up to 456 lp/mm) |
| Contrast Ratio | 2% to 100% |
| Substrate | Soda-lime glass (quartz optional) |
| Coating | Chromium |
| Plate Dimensions | 23 × 23 mm |
Overview
The Inframet Visible Light Target is a high-precision transmission-type resolution test target engineered for quantitative evaluation of visible-light imaging systems—including machine vision cameras, scientific CMOS/CCD sensors, optical microscopes, and industrial inspection lenses. Based on the standardized USAF 1951 pattern, it operates on the principle of spatial frequency discrimination: resolving increasingly fine line-pair elements enables objective determination of modulation transfer function (MTF), limiting resolution, contrast sensitivity, and system-level aberration effects. Unlike reflective targets—whose surface scattering and coating variability introduce measurement uncertainty—this transmission target delivers sub-micrometer feature fidelity via photolithographic fabrication on optically flat substrates. Its design supports both qualitative pass/fail assessment and traceable, repeatable metrology in calibration laboratories and R&D environments.
Key Features
- Photolithographically defined chromium-on-glass pattern ensures dimensional stability, edge acuity, and long-term repeatability—critical for ISO 12233-compliant resolution testing.
- USAF 1951 layout with 3-bar group structure (Groups 0–7 standard; optional extension to Group 8) provides logarithmically spaced spatial frequencies from 1 to 228 lp/mm (extendable to 456 lp/mm), enabling characterization across wide dynamic range of optical performance.
- Controlled contrast ratio (2%–100%) allows systematic evaluation of low-contrast resolution limits and sensor noise floor interaction—essential for medical endoscopy, semiconductor wafer inspection, and autonomous vehicle camera validation.
- 23 × 23 mm active area accommodates standard lens mounts and collimated beam paths; optional quartz substrate available for UV-enhanced transmission or thermal stability in environmental chambers.
- Manufactured in Poland under ISO 9001-certified processes; each target includes individual calibration certificate referencing NIST-traceable interferometric verification of line width and pitch uniformity.
Sample Compatibility & Compliance
The Inframet Visible Light Target is compatible with all visible-spectrum imaging platforms operating between 400–700 nm. It is routinely deployed in compliance-critical workflows aligned with ASTM E3084 (Standard Practice for Resolution Testing of Imaging Systems), ISO 12233:2017 (Photography — Electronic still picture imaging — Resolution measurements), and IEC 62676-5-2 (Video surveillance systems — Part 5-2: Test methods for camera resolution). Its transmission geometry eliminates specular artifacts common in reflective targets, supporting GLP/GMP-aligned validation protocols where measurement traceability and operator-independent results are mandated.
Software & Data Management
While the target itself is hardware-based, it integrates seamlessly with industry-standard analysis software including Imatest, OptiCAL, and MATLAB-based MTF calculation toolkits. When used with calibrated illumination (e.g., stable LED backlight with <±0.5% intensity drift), the target supports automated ROI extraction, contrast thresholding, and full MTF curve generation. All associated measurement data—including image acquisition metadata, illumination settings, and environmental conditions—can be logged with time-stamped audit trails compliant with FDA 21 CFR Part 11 requirements when paired with validated software platforms.
Applications
- Verification of telecentric and macro lens resolution in precision manufacturing metrology
- Baseline calibration of hyperspectral and multispectral visible-band sensors
- Validation of autofocus algorithms and depth-from-defocus pipelines
- Quantitative comparison of anti-aliasing filter efficacy across sensor generations
- Supporting ISO/IEC 17025-accredited laboratory proficiency testing for optical metrology services
FAQ
What is the difference between transmission and reflection-type USAF 1951 targets?
Transmission targets use a transparent substrate with patterned chromium absorption, yielding superior edge definition and minimal scatter—ideal for high-fidelity MTF measurement. Reflective variants suffer from substrate roughness, coating non-uniformity, and angle-dependent reflectance, limiting their use to qualitative checks.
Can this target be used for infrared or UV imaging systems?
The standard soda-lime glass version is optimized for 400–700 nm. Quartz substrate option extends usable range down to ~190 nm (UV) and up to ~2.2 µm (near-IR), subject to coating transmittance and thermal expansion constraints.
Is NIST traceability provided with each unit?
Yes—each target ships with a manufacturer’s calibration certificate documenting measured line widths, pitch deviations, and contrast uniformity, referenced to NIST-traceable interferometric standards.
How is the target mounted during testing?
It is designed for integration into standard optical breadboards or custom holders using kinematic or vacuum-based fixtures; recommended working distance is ≥5× focal length of the test lens to minimize field curvature effects.
Does Inframet offer custom pattern layouts beyond USAF 1951?
Yes—custom designs including sine-wave targets, slanted-edge patterns, and multi-contrast step wedges are available under OEM agreement with documented process control and metrology validation.
