Abstract
A wide selection of lenses is very useful to the thermographer working in a research environment, where applications can vary from week to week. Both wide angle and telephoto infrared lenses are widely used alternatives to the standard lenses typically supplied by IR camera manufacturers. However, in some extreme applications the need arises for additional image magnification. In these cases, the thermographer must rely on an IR microscope for close-up work with a field of view on the order of 1.3 to 15.8 mm, or a telescope for working at a distance on the order of meters or kilometers. The advantages of using an IR microscope and reflecting telescope will be discussed, as well as the challenges and characteristics of using these instruments.