Why can mobile phone cameras “see” infrared?
photo: paul (dex) busy @ work Most cameras are designed to capture an image of what people can see. Hence a good camera would only detect EM radiation in the visible light spectrum (between 400nm and 700nm). Yet the charged couple devices used within cameras are typically manufactured to pick up EM radiation between 350nm and 1000nm. This means they are capable of detecting infrared light too (between 700nm and 1,000nm is infrared). To improve image quality, camera manufacturers typically add films and filters to block out infrared light and ensure only visible light reaches the CCD. If the infrared radiation was recorded by the camera and appeared in our photos, the photos would not be an accurate representation of what we can see – i.e. what we want to photograph! Mobile phone cameras tend to be produced a lot cheaper than proper digital cameras and hence the vast majority of mobile phone cameras have a much thinner film/filter to block out infrared light. The lack of infrared filter
