Hypervision Cameras
The Hypervision HSI camera is a push-broom hyperspectral camera based on the qtec C-series platform.
All qtec cameras are a complete platform, combining imaging capabilities with a full Linux computer (CPU plus GPU) to allow for on-board image processing.
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Two versions for either the VIS-NIR (400-1000nm) or the VIS-SWIR (430-1700nm) ranges
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Different possible slit sizes to choose from: 20 (default) or 30um
- The slit size influences both the spectral and spatial resolutions
We are currently working on offering 2 different options of gratings in our Hypervision camera line.
The current high resolution one (with 65 lines/mm) and a new lower resolution option (with 24 lines/mm), which will allow for faster framerates (less bands) and improved light sensitivity as a trade off for the reduced resolution.
Technical details
Offner Spectrograph
The Hypervision uses an Offner Spectrograph instead of the more traditional approach that uses refractive (lens based) spectrographs. It's main advantage is its ability to provide a wide field of view with almost no geometric distortion and very low levels of aberration.
Zero "Smile" & "Keystone"
In many HSI cameras, the spectral image suffers from "Smile" (where a straight slit appears curved on the detector) and "Keystone" (where the spatial magnification varies with wavelength). The concentric, all-reflective nature of the Offner design inherently cancels these aberrations. This ensures that every pixel on the sensor represents a clean, undistorted relationship between a specific spatial point and its corresponding spectrum.
Full-Spectrum Achromatism
Refractive systems (using glass lenses) suffer from chromatic aberration, where different colors focus at different distances. This requires complex, heavy corrective elements. Because the Hypervision uses mirrors and a reflective grating, the focal point remains constant across the entire spectral range. This allows for seamless imaging through the whole wavelength range without focus shift.
High Throughput and SNR
Traditional spectrometers often struggle with "stray light" or light loss at lens interfaces. The Offner relay provides a high Étendue (light-gathering capacity). By minimizing the number of optical surfaces and using high-reflectivity coatings, the Hypervision maintains a high Signal-to-Noise Ratio (SNR), even in low-light conditions or high-speed "push-broom" scanning.
Thermal Stability & Operating Environment
While the all-reflective Offner Spectrograph is inherently more stable than refractive (lens-based) systems, spectral precision is still influenced by the thermal environment. To ensure the highest levels of data integrity and calibration accuracy, users should consider the following ambient temperature guidelines:
The Hypervision is precision-calibrated at an ambient temperature of 22°C. For applications requiring maximum spectral stability and peak focus, we recommend maintaining an operating environment between 17°C and 27°C.
The camera is rated for reliable operation between 5°C and 40°C. When operating at the edges of this range (outside the optimal 17–27°C window), the system remains fully functional, but users may observe:
- Marginal focus degradation: Minor softening of spatial resolution.
- Spectral shifts: Nominal wavelength shifts (up to +-10nm) due to the thermal expansion of mechanical housings.
For most industrial and field applications, these variances fall within acceptable tolerances. However, for high-sensitivity laboratory analysis or quantitative chemical mapping, maintaining the optimal temperature range is strictly recommended.
Second order diffractions
Because the detector covers a broad spectral range, higher transmission orders from the diffraction grating become observable, causing overtones. The periodic structure of the grating produces multiple reflection orders, where the zeroth order contains the non-diffracted primary signal, and the higher orders spread the light based on wavelength.
As the detector captures this wide range of wavelengths, the higher orders can spatially overlap with the primary signal, resulting in overtones in the measurement.
Multiple reflection orders caused by the grating
If necessary these effects can be counteracted by for example adding an external long-pass filter in front of the optics to limit the spectral range. It effectively removes the visible part of the spectrum and with it the overtones that it causes in the infrared range. Another similar option is to add a long-pass filter internally, covering only the bottom part (infrared range) of the sensor, in order to filter the visible range overtones.
However, since these methods introduce additional optical losses — thereby decreasing the signal-to-noise ratio — they are not included in the standard hardware setup.
Platform
| Hardware | Description |
|---|---|
| Model | qtec-C-series |
| APU | AMD Ryzen Embedded V1605B with Radeon™ Vega 8 Graphics [^V1605B] |
| Available sensors | Sony IMX990 or GSENSE2020 |
| Bitstreams | corna-tokyo/draco-tokyo or pisces-paris 1 |
Qtec is currently in the process of developing a new cheaper series of HSI cameras which won't have any internal processing capabilities and will be GigE Vision based instead.
Dimensions
Mounting points thread: M6-6H X ↧ 6
Hardware interfaces
See the Quick Start Guide for basic information on how to power and connect to the camera.
Refer to the Hardware Guide for more detailed information on the available hardware interfaces.
Software
In order to make the process of working with the Hypervision HSI cameras easier qtec has developed the both a GUI (HV Explorer) and a SDK (HV SDK) for it.
The HV Explorer is a Python based helper tool developed by qtec for visualizing and manipulating HSI data cubes. Its goal is to aid in the exploratory (proof of concept) phase of projects, but all the functions available in the HV Explorer are implemented in the HV SDK library, which is Rust based and has bindings available for other programming languages (Python bindings currently available and C/C++ bindings coming soon). Which makes it easy to take a workflow from the HV Explorer and implement it as a standalone program using the HV SDK library.
See the HV Explorer and HV SDK specific sections for more detailed information and in depth tutorials/guides.