How to Choose a SWIR Line Scan Camera for Machine Vision
A practical guide to selecting the right SWIR line scan camera based on wavelength, resolution, inspection width, object speed, working distance, and lens requirements.
Selecting a SWIR line scan camera is not simply a matter of choosing the highest resolution available.
This guide walks through the key factors to consider when selecting a Short-Wave Infrared (SWIR) line scan camera for industrial machine vision.
1 Do You Really Need SWIR?
The first question is not which SWIR camera to buy. It is what information your current visible-light camera cannot provide.
RGB / Visible Imaging
RGB cameras are excellent for conventional machine vision tasks such as:
- Color inspection
- Shape measurement
- Surface defects
- Texture analysis
- Pattern recognition
SWIR Imaging
SWIR can provide additional information for applications involving:
- Material identification
- Moisture detection
- Food and agricultural sorting
- Recycling
- Films and coatings
- Semiconductor and solar materials
2 Line Scan or Area Scan?
Once SWIR is selected, the next decision is whether you need a line scan or area scan camera.
| Inspection Requirement | Recommended Camera |
|---|---|
| Individual stationary objects | Area Scan |
| Parts positioned separately | Area Scan |
| Conveyor inspection | Line Scan |
| Continuous web inspection | Line Scan |
| Roll-to-roll production | Line Scan |
| Continuous material sorting | Line Scan |
3 What SWIR Wavelength Do You Need?
SWIR cameras are available in different spectral ranges. For many industrial machine vision applications, the 950–1700 nm range provides a practical solution for material inspection and classification.
950–1700 nm SWIR
This wavelength range is suitable for applications where visible imaging does not provide sufficient material contrast.
However, wavelength should always be selected based on the actual material and inspection objective.
4 How Many Pixels Do You Need?
Resolution should be selected according to inspection width, minimum defect size, object speed, and optical performance.
5 512 vs 1K vs 2K: Which One Should You Choose?
A practical option for standard inspection, sorting, and applications where moderate spatial resolution is sufficient.
A balanced option for general industrial SWIR inspection and material analysis.
Designed for applications requiring higher spatial sampling and more detailed inspection.
Higher resolution does not automatically mean better performance. The correct resolution depends on the complete imaging system.
6 Define Inspection Width Before Selecting Resolution
Instead of asking whether you need 1K or 2K first, define your inspection width and minimum feature size.
500 mm inspection width
500 mm inspection width
500 mm inspection width
These are simplified theoretical sampling calculations. Actual defect detection depends on optical resolution, focus, illumination, contrast, sensor performance, target characteristics, and image processing.
7 What About Object Speed?
Line scan imaging is closely related to the movement of the target. If your material moves continuously, the camera must acquire lines fast enough to maintain the required image sampling in the direction of motion.
For high-speed production lines, motion synchronization can become particularly important. An encoder can be used to synchronize image acquisition with conveyor or material movement.
8 How to Choose the Right SWIR Lens
A camera is only one part of a SWIR imaging system. The lens determines how the inspection area is projected onto the sensor.
Sensor Compatibility
The lens should adequately cover the camera sensor and provide the required image quality.
Focal Length
Focal length affects field of view, magnification, and the overall optical configuration.
Working Distance
The distance between the lens and target affects the required focal length and field of view.
SWIR Transmission
For a 950–1700 nm camera, the lens should be designed for the required SWIR wavelength range.
9 Camera + Lens Matching
Instead of selecting the camera and lens separately, use the application requirements to determine the complete optical configuration.
This becomes increasingly important when moving from a 512-pixel camera to a 1K or 2K camera, where optical performance can have a greater influence on the final image quality.
10 What About SWIR Illumination?
Good SWIR imaging also depends on illumination. The camera detects reflected or transmitted SWIR radiation, so the available signal depends on the light source and material characteristics.
Complete SWIR Imaging System
Camera + Lens + Illumination + Motion + Image Processing
11 Which Applications Are Suitable for SWIR Line Scan?
SWIR line scan cameras are particularly useful when material information and continuous inspection are both important.
Food & Agricultural Sorting
Additional contrast related to material composition, moisture, and product characteristics.
Recycling
Helps distinguish materials that have similar visible appearance.
Film & Coating
Provides additional contrast for films, coatings, adhesives, and material differences.
Semiconductor Inspection
Can complement visible imaging for selected semiconductor and electronics inspection applications.
Solar Cell Inspection
Supports inspection of photovoltaic materials and continuous production processes.
Moisture Detection
Different moisture conditions can produce different SWIR responses for non-contact inspection.
12 SWIR Line Scan Camera Selection Checklist
Before choosing a camera, define the following parameters:
What material or product are you inspecting?
What information is missing from RGB?
Is the target continuously moving?
Does the application require 950–1700 nm?
How wide is the area that needs to be inspected?
What is the smallest defect you need to detect?
How fast does the target move?
How far is the camera from the target?
What focal length and SWIR transmission are required?
What SWIR light source and geometry will be used?
Quick SWIR Camera Selection Guide
| Your Requirement | Starting Point |
|---|---|
| Standard SWIR inspection | iBt-SW05K |
| General industrial inspection | iBt-SW1K |
| Higher spatial resolution | iBt-SW2K |
| Continuous moving material | Line Scan |
| Material identification | SWIR |
| Roll-to-roll inspection | SWIR Line Scan |
| Wide inspection area | Higher pixel count + appropriate lens |
| Fine defects | Higher resolution + suitable SWIR optics |
Build a Complete SWIR Vision System
Choosing the camera is only the beginning. A practical SWIR line scan system may include the following components:
01 — SWIR Line Scan Camera
Select the appropriate resolution and spectral range.
02 — SWIR Lens
Match focal length, sensor size, field of view, working distance, and optical resolution.
03 — SWIR Illumination
Provide sufficient and uniform illumination for the target material.
04 — Motion Synchronization
Use conveyor speed or encoder information to synchronize image acquisition.
Start With the Application, Not the Camera
Choosing a SWIR line scan camera does not have to start with the camera model.
Find the Right SWIR Line Scan Camera
Vision Datum offers SWIR line scan camera options in the 950–1700 nm range for industrial machine vision applications.
Not sure which configuration fits your application? Start with your inspection material, inspection width, object speed, working distance, and minimum defect size.
Explore SWIR Cameras