Camera Mechanism and Structure
Generally, in camera modules of digital cameras and smartphones,
IR-cut filters, which absorb infrared rays, are generally installed in the camera modules of digital cameras and smartphones.
This is to prevent so-called “white splash" and bring the photo closer to the naked eye.
(Some cameras, such as night vision cameras, do not have IR cut filters.)
The imaging sensor itself, which is the retina of the camera, is sensitive to infrared light, so this IR-cut filter must be removed in order to achieve the infrared effect.
The structure of a digital camera or smartphone camera module is illustrated below.
(1) Normal digital camera
(2) Camera module of a smartphone
If you only want to increase the sensitivity to infrared (or long-wavelength = red) light, you can remove the IR cut filter.
e.g.) When photographing nebulae in astrophotography
If you want to get the effect of transmission by infrared light, visible light will be in the way,
IR cut filter must be removed and then an “IR transmission filter" that transmits only IR must be attached.
This is an example of an IR transmitting filter.
See the summary article below for more information on preparing for infrared camera modifications.