When Was Thermal Imaging Invented? A History Timeline
Thermal imaging has a longer history than most homeowners realize. The fundamental discovery, that there is invisible radiation beyond red light, dates to 1800, and the first device that could form an image from heat radiation appeared in 1929. The technology then spent four decades almost entirely in military and aerospace settings before reaching industrial users in the 1970s and consumers in the 2000s. The question, when was thermal imaging invented, has no single date answer because the technology evolved across multiple breakthroughs by different inventors. This guide walks the timeline.
Part of our Thermal Imaging for Homes guide — start there for the full picture →
1800: William Herschel discovers infrared radiation
The story starts with William Herschel, the German-British astronomer who built the largest telescopes of his era. In 1800, Herschel was testing optical filters by passing sunlight through a prism and measuring the temperature in each color of the rainbow with a thermometer. He noticed that the thermometer kept rising as he moved beyond the red end of the visible spectrum into a region with no visible light. He had discovered infrared radiation, calling it calorific rays. The finding established that there is invisible electromagnetic energy beyond the red end of visible light, the foundation on which every thermal imaging technology since has been built.
1880 to 1900: Bolometers and early IR detectors
For most of the nineteenth century, infrared detection was limited to thermometers and rudimentary instruments. In 1880, American astronomer Samuel Pierpont Langley invented the bolometer, an electrical device that measured temperature changes through resistance variations in a thin metal strip. The bolometer was far more sensitive than a mercury thermometer and could detect heat from a cow at a distance of a quarter mile, according to records cited by the U.S. National Library of Medicine’s history of science archives. The bolometer was the conceptual ancestor of the modern microbolometer found in every consumer thermal camera, though the underlying technology took more than a century to miniaturize.
1929: Czerny invents the first thermograph
The leap from single-point IR detection to forming an actual image came in 1929 when Hungarian physicist Kalman Tihanyi developed an early electronic camera with IR sensitivity for British anti-aircraft defense. The same year, German physicist Marianus Czerny invented the Evaporograph, a device that produced a visible image by allowing IR radiation to differentially evaporate a thin oil film on a membrane. The Evaporograph was crude, slow, and required carefully controlled conditions, but it was the first instrument that could form a two-dimensional thermal image. Both inventions were primarily military, and most of the work stayed classified until after World War II.
1947 to 1960s: Military thermal imaging matures
World War II accelerated military investment in IR detection for night reconnaissance and anti-aircraft fire control. The U.S. Army developed the first practical military thermal imaging system in 1947, using cooled lead sulfide and indium antimonide detectors. Through the 1950s and 1960s, military thermal imagers grew sophisticated enough for tactical use, including the FLIR (Forward Looking InfraRed) systems mounted on aircraft for navigation and targeting. These devices required liquid nitrogen cooling, weighed dozens of pounds, and cost a fortune, but they proved the principle that thermal imaging could produce useful tactical intelligence. The acronym FLIR, originally the name of the military capability, later became the brand name of the company that commercialized the technology for civilian use.
1965 to 1970s: Texas Instruments and industrial adoption
Civilian use began in the mid-1960s when Texas Instruments licensed military thermal imaging technology for industrial applications, particularly electrical maintenance and steel manufacturing. The devices were still bulky and required cooling, but power utilities began using them to inspect transformers and substations for hot spots. AGEMA, a Swedish company that eventually became part of FLIR Systems, released the Thermovision 750 in the early 1970s, the first industrial thermal camera with self-contained operation. The cost remained well into five figures, limiting adoption to large industrial users and government labs. The U.S. Department of Energy’s history of building diagnostics notes that thermal imaging entered building envelope work in this period as energy crises of the 1970s drove interest in insulation effectiveness. Our coverage of the modern technology lives in the home inspection tools pillar and the sibling guide on how thermal cameras work.
1980s to 1990s: Inframetrics and uncooled microbolometers
The decisive shift toward affordable thermal imaging came in the 1980s with the development of uncooled microbolometer arrays. Researchers at Honeywell, working under U.S. defense contracts, developed vanadium oxide microbolometer technology that worked at room temperature, eliminating the bulky and expensive cooling systems that had defined every prior generation. Inframetrics, a Massachusetts-based company founded in 1979, introduced uncooled commercial thermal cameras through the 1980s that brought prices down from $50,000 to under $20,000 for industrial users. FLIR Systems, founded in 1978, focused on military and airborne thermal systems and gradually expanded into commercial markets through the 1990s. By the end of the decade, an industrial thermal camera could be carried in one hand and cost under $10,000.
2000s: FLIR consumer launch and price collapse
The 2000s saw thermal imaging cross into the price range a working tradesperson could justify. FLIR launched the i-Series in 2007, a pistol-grip thermal camera at around $3,000 that became the standard inspector’s tool for the next decade. The 2010s brought further price drops, with FLIR’s E-Series mid-tier cameras hitting $1,500 by mid-decade. Seek Thermal, founded in 2013, launched smartphone-attachment thermal cameras at $250, the first time a thermal imager was affordable to a curious consumer. FLIR responded with the FLIR One Pro at a similar price point. Hikmicro, the Hikvision consumer arm, entered the U.S. market in the late 2010s with aggressive pricing that further compressed margins across the category.
2020s: Sensor commoditization and smartphone parity
The 2020s have been about resolution and sensitivity gains at flat or falling prices, plus rapid commoditization of mid-tier sensors. Hikmicro, Topdon, Infiray, and other Chinese manufacturers entered the global market with handheld units priced well below FLIR’s equivalents, forcing the established players to add features or cut margins. Teledyne acquired FLIR in 2021 for $8 billion, signaling that thermal imaging had become a mature commodity category rather than a frontier technology. By 2026, a 256 by 192 thermal sensor that would have cost $5,000 in 2010 sells in a $400 smartphone attachment, and 640 by 480 professional units run $2,000 to $3,500. The technology that took 130 years to develop from Herschel’s prism experiment is now in the pockets of inspectors, electricians, HVAC technicians, and curious homeowners across the country.
Patent and technology history shaping the modern industry
The patent landscape and corporate consolidation history of thermal imaging is worth understanding because it shapes today’s pricing and product availability. Honeywell’s microbolometer research in the 1980s, funded under U.S. defense contracts, produced foundational patents that the company later licensed to commercial manufacturers, fueling the commercial market through the 1990s. FLIR’s acquisition of Inframetrics in 1999 and AGEMA in 1997 consolidated the early commercial thermal industry under one corporate umbrella, giving FLIR a roughly 60 percent share of the global commercial market by the mid-2000s. The 2014 export-control rules limiting consumer thermal cameras to 9 Hz refresh rates (versus 30 to 60 Hz for export-controlled industrial gear) shaped the consumer product market that emerged with smartphone attachments. Teledyne’s $8 billion acquisition of FLIR in 2021 consolidated the largest player further but coincided with the rise of competitive Chinese manufacturers (Hikmicro, Topdon, Infiray) that have since aggressively expanded U.S. market share. The pattern of consolidation and competitive entry continues to shape pricing and feature availability today.
The institutional milestones that drove adoption
Beyond the technology curve, several institutional milestones drove civilian thermal imaging adoption. The U.S. Department of Energy’s residential building diagnostics program in the 1980s legitimized thermography as an energy auditing tool, with home performance assessments increasingly including thermal scans. The American Society for Nondestructive Testing (ASNT) published the first Level I and Level II thermographer certifications in the 1990s, formalizing the credential structure that working thermographers still earn today. ASHI added thermal imaging as an ancillary inspection service category in the early 2000s, encouraging member inspectors to add the capability. InterNACHI launched the Infrared Certified credential in 2007, the same year FLIR launched the i-Series consumer line, creating both the supply and the demand for residential thermal scanning at scale. Each institutional milestone moved the technology from specialty equipment toward mainstream inspection practice.
What the next decade is likely to bring
Several developments are visible on the horizon for thermal imaging through the late 2020s and early 2030s. AI-assisted interpretation, with the camera or paired software flagging anomalies automatically without expert human review, is already appearing in early commercial products. Higher resolution at lower prices, with 1024 by 768 microbolometers projected to reach the $3,000 price point by 2028. Integration with drone and robotic platforms is expanding rapidly, autonomous roof inspections and agricultural surveys are increasingly conducted by drones carrying thermal payloads. Smartphone-native thermal sensors, built into the phone rather than requiring an attachment, have been announced by several manufacturers and may reach mainstream consumer phones by the late 2020s. Each development continues the trajectory that started with Herschel’s prism, expanding the user base and the diagnostic capability of the technology while compressing the price barrier that limited adoption for most of its history.
Key inventors and companies through the timeline
A short list of the people and organizations that shaped thermal imaging tells the story compactly. William Herschel (1738-1822), British astronomer, discovered infrared radiation in 1800. Samuel Pierpont Langley (1834-1906), American astronomer, invented the bolometer in 1880. Marianus Czerny (1896-1985), German physicist, developed the first thermograph (Evaporograph) in 1929. Honeywell Corporation, U.S. defense contractor, developed vanadium oxide microbolometer technology in the 1980s under classified research funding. Inframetrics, Massachusetts-based commercial pioneer, introduced uncooled commercial thermal cameras through the 1980s before being absorbed into FLIR. AGEMA, Swedish industrial thermography company, also absorbed into FLIR in 1997, brought European thermal imaging expertise to the consolidated entity. FLIR Systems, founded by Larry Browne in 1978, became the dominant global commercial brand through the 1990s and 2000s before being acquired by Teledyne in 2021. Each name on this list contributed a specific innovation or commercial development that compounded into the modern technology stack.
How the history affects today’s product choices
The 130-year arc of thermal imaging development directly shapes the choices today’s buyers face. The high cost of pro-tier cameras reflects the still-specialized manufacturing of germanium optics and uncooled microbolometer arrays, technology that took decades to refine and remains expensive at high resolution. The export-control rules limiting consumer units to 9 Hz refresh rates reflect Cold War-era concerns about military applications that may seem dated but still bind manufacturers and shape the consumer market. The dominance of FLIR as a brand name reflects three decades of military and commercial market leadership that gave the company brand equity worth maintaining even after the Teledyne acquisition. The aggressive pricing of new Chinese entrants reflects state-supported manufacturing scale and a willingness to operate on thinner margins to gain market share. Buyers benefit from this competitive history through lower prices and broader choice, but they also navigate a market where brand reputation, after-sales support, and warranty coverage vary significantly across what otherwise looks like comparable hardware.
References
- ENERGY STAR: Seal and Insulate — U.S. Environmental Protection Agency (ENERGY STAR)
- Infrared Certified Inspector Program History — InterNACHI
- History of Infrared Spectroscopy and Detection — NCBI / National Library of Medicine
- Standards for Building Thermography — ASHRAE
Frequently asked questions
Who invented thermal imaging?
There is no single inventor. William Herschel discovered infrared radiation in 1800, Samuel Langley invented the bolometer in 1880, and Marianus Czerny developed the first thermograph in 1929. Modern thermal imaging emerged from decades of military and industrial development.
When did thermal cameras become affordable for homeowners?
Affordable thermal cameras for consumers arrived in 2013 to 2015 when Seek Thermal and FLIR introduced smartphone-attachment units around $250. Before that, even basic handheld thermal cameras started near $3,000.
Was thermal imaging originally a military technology?
Yes. Most of the foundational thermal imaging work between 1929 and the 1970s was funded by military programs in the U.S., U.K., and Germany. Civilian and industrial use only opened up after Cold War declassification.
What does FLIR stand for?
FLIR is an acronym for Forward Looking InfraRed, originally a military designation for IR systems mounted on aircraft for navigation and targeting. The company FLIR Systems, founded in 1978, adopted the term as its corporate name.
Thermal imaging cameras
Infrared cameras reveal hidden moisture, missing insulation, and air leaks. Phone-attachment models are the budget entry point; standalone units have higher resolution.
| Product | Why | Buy |
|---|---|---|
 FLIR ONE Pro (phone) | Plugs into iPhone/Android; inspector favorite. | Amazon — $349.00 |
 Topdon TC001 | High-res phone module at a low price. | Amazon — $199.99 |
 FLIR C5 Compact | Standalone pocket camera with Wi-Fi. | Amazon — $611.50 |