Thermal imagery and visible cameras have different usage and proposes, also both operates under different principals, in the following table we wil share the main differences between them:
Difference in image formation
Thermal camera: produces images in grayscale color that represent the variations of the temperature of the object scanned. The warmest areas appear brighter colors (e.g., white, yellow, red) while cooler areas appear in darker colors (e.g., black, blue, green).
Visible Camera: creates color images based on the visible light spectrum. Colors and brightness levels in the image correspond to the way the human eye perceives light and color.
Difference in applications
Thermal camera: used in night vision, security and surveillance, industrial inspection, firefighting, medical diagnostics, and building inspections.
Visible Camera: used in everyday photography, videography, security, documentation, and any application where the human eye needs to see the image.
Difference in performance
Thermal camera: effective in complete darkness, through smoke, fog, and light rain, and can detect objects based on their heat signatures.
Visible camera: requires some level of visible light to function and is less effective in low light or obscured conditions like smoke or fog.
Difference in operating principles
Thermal camera: detects infrared radiation (heat) emitted by objects. Every object with a temperature above absolute zero emits some level of infrared radiation, which thermal cameras capture to create an image based on temperature variations.
Visible camera: captures visible light reflected off objects. It operates within the visible spectrum (approximately 400-700 nanometers) and produces images based on the intensity and color of the reflected light.
Difference in image resolution
Thermal camera: typically has lower resolution compared to visible cameras. Details in thermal images are based on temperature differences rather than visual details.
Visible camera: generally offers higher resolution and detail, capturing the fine visual details and colors of the scene.
Difference in prices
Thermal camera: generally more expensive due to the specialized sensors required to detect infrared radiation.
Visible camera: more affordable and widely available, with a range of options from consumer-grade to professional-grade.
Difference in technology
Thermal camera: uses microbolometers or other infrared detectors to sense heat.
Visible camera: uses CMOS or CCD sensors to capture light.
Difference in limitations
Thermal camera: cannot see through glass or water effectively, and external environmental factors can affect accuracy.
Visible camera: limited in darkness and adverse weather conditions, relies on ambient light.