Fixed Focal Length Lenses
Featured Product from Avantier Inc.
Avantier produces custom and stock fixed focal length lenses for robotics, machine vision, and other imaging applications, engineered to perform reliably at a predetermined focal length.
A fixed focal length lens — also called a prime lens, factory automation (FA) lens, or C-mount lens when built with a C-mount interface — is a multi-element assembly with a constant focal length and a single angular field of view, built for direct integration into imaging systems. Focal length is the distance from the lens to the point where the image forms most sharply, and it determines both magnification and angle of view.
Key characteristics:
No zoom capability, but not limited to a single working distance
- Defined by an optimal working distance and a minimum working distance, with no fixed maximum — supports imaging at both close range and farther distances (distant objects appear smaller in frame)
- Typically built with larger maximum apertures, supporting wider fields of view and greater light throughput in low-light conditions
Custom Fixed Focal Length Lens Specification
| Specification | Parameter |
| Field of View (FOV) | Customizable; typical diagonal FOV from 10° to 120° (depends on sensor size and focal length) |
| Sensor Format Max | Up to 4/3″, APS?C, or Full Frame (35 mm) |
| Resolution | Up to 12 MP and above (matched to pixel pitch and application) |
| Focal Length | Custom range: wide?angle to telephoto (e.g., 4 mm to 300+ mm) |
| External Dimension | Custom design; typical diameter Φ30–Φ80 mm, length 30–120 mm |
| Mount Type | C?Mount, F?Mount, M42, M58, or custom?designed interface |
| Filter Thread | Customized to front barrel size (common sizes: M25.5, M27, M30.5, M37.5, M43, M46, M49, M52, M55, M58, M62, M67, M72, M77, M82, M86, M95, M105, etc.) |
| f/# | Customizable; typical F1.4–F16, down to F0.95 for low?light applications |
| Focusing Range | From minimum working distance to infinity; MWDR varies by design (typical 0.1 m – 5 m) |
Applications of Fixed Focal Length Lenses
- Used across machine vision and robotic systems for reliable, consistent imaging — Fixed focal length keeps magnification and field of view constant across repeated cycles, supporting the repeatability automated systems require.
- Common in research, medical imaging, surveillance, defense, industrial, and conservation applications, these fields often need lenses matched to a specific working distance and field of view for task-specific setups.
- In photography applications, wider apertures produce shallower depth of field, isolating the subject from the background.
Avantier’s custom optics are developed under precision engineering standards and rigorous quality control at every stage of design and production. Contact Avantier to place an order or schedule a consultation to talk about your fixed focal lens application.
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