In addition to the standard infrared lens that comes with thermal imagers, some infrared cameras provide a choice of optional lenses. These macro, telephoto, and wide angle lenses make it possible to inspect targets that—due to their size and distance—would be challenging to see with a standard lens.
Germanium is the material of choice for quality infrared lenses because the element is transparent in the infrared spectrum and has a high index of refraction. Along with an engineered coating, Germanium provides the most efficient material to transmit energy to the detector to produce high quality infrared images.
Better macro and telephoto add-on lenses are called “smart lenses” because they do not need to be calibrated to a specific camera and are interchangeable among compatible cameras. Fluke offers a line of such add-on lenses for certain infrared cameras.
The following chart offers guidelines for selecting add-on lenses for your applications.
|Lens||Use to scan||Applications|
|Wide Angle||Large targets, viewed from a relatively close distance|
|2x telephoto||Small to medium sized targets, viewed from a distance|
|4x telephoto||Small targets, viewed from a great distance||Most relevant to those working in|
|Macro||Tiny to microscopic targets, viewed from extremely close||Engineers and scientists working in|
Audience can be found in universities and research organizations, process development, and micro-electronics design companies.