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Artistic representation of spectral wavelength bandsSpectral wavelength bands©️ iStock

Spectral bands: What they are and why they matter for imaging applications


This guide simply explains light across the spectrum and how important spectral bands are for imaging applications.

We will examine the advantages and disadvantages that exist in the imaging applications that depend on the various spectral bands and how they can be chosen and mixed to deliver the best outcomes for a specific purpose.

A non-technical explanation of spectral bands for imaging applications

Although we are experts in optical systems and photonics, we appreciate that not everybody is. That is why we have made this guide as straightforward as possible.

We promise useful insights, practical examples and comprehensible explanations of how spectral bands relate to imaging in different circumstances.

Download the complete guide below.

What is a spectral band?

A spectral band is a range of wavelengths. There are several spectral bands. Together they make up the light spectrum.

A spectrum is the collective name for all forms of light, both visible and non-visible.

Humans can only see the visible waveband, so whilst wavelength determines light colour, not all parts are visible to our eyes. This is where imaging applications help.

For example, Short-Wave Infrared might be used by airport security to allow for the detection of liquid in an opaque bottle.

Near-Infrared might be used to enable astronomers to see more of the galaxy at night through photomultiplier tubes.

How does heat affect a spectral band?

Consider the difference in colour of a red-hot poker and a white-hot poker.

The more heat a body produces, the more wavelengths it produces light at.

A red-hot poker is only hot enough to produce light at one wavelength-red.

A white-hot poker is hot enough to produce light at multiple wavelengths. All the wavelengths form a spectral band that shows as white light.

What is in the guide?

In this guide, we will go through what a spectrum is and what wavebands are.

We will then detail how lens systems use light, including ultraviolet (UV) and visible light before going on to explain Near Infrared (NIR), Short Wave Infra-Red (SWIR), Medium and Long Wave Infrared (MWIR, LWIR) applications.

Who is this guide for?

This guide is for anyone who wants to understand spectral bands in imaging applications, including what spectral bands are and how we use the various bands to create systems which, put crudely, allow us to see what the naked eye can't.

Download the guide below or contact us to discuss our imaging applications.

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