4 Key Differences between Infrared Lenses and Ordinary Lenses

Here is content list：

• Different Working Wavelength Ranges

• Different Optical Materials

• Different Imaging Effects

• Different Application Scenarios

  
  

Different Working Wavelength Ranges

1. Ordinary Lenses
   Ordinary lenses are mostly made for the visible light part. The wavelengths they work with are usually between 380 and 780 nanometers. That's what our eyes can see. Ordinary lenses can focus and take nice pictures of visible light. For example, when we're taking pictures of people or landscapes, these lenses are designed to make the light in this range come together on the imaging plane to make clear images.

2. Infrared Lenses
   Infrared lenses work in a range that goes beyond visible light. Generally, it starts from above 780 nanometers. The common near-infrared lenses work in a range from around 780 nanometers to 3,000 nanometers. This lets them catch infrared rays. In some situations where we need to take pictures in the infrared range, like infrared thermal imaging or night vision, infrared lenses are really useful. For instance, in security monitoring, when there's not enough visible light at night, infrared lenses can use the infrared rays from objects to make images so we can still see what's going on.

   
   

Different Optical Materials

1. Ordinary Lenses
   Ordinary lenses usually use optical glass. This glass is good at letting visible light through and has nice optical properties. It can cut down on things like chromatic aberration and spherical aberration to make sure the pictures in the visible light range are clear and accurate. For example, crown glass and flint glass are used together in a good way to fix different kinds of problems and make sure ordinary photography and imaging work well.

2. Infrared Lenses
   Infrared lenses need special materials that can let infrared rays through. Since ordinary optical glass doesn't let much infrared through, materials like germanium (Ge) and zinc sulfide (ZnS) are often used for infrared lenses. Germanium is really good at letting infrared through, especially in the infrared atmospheric window bands of 3 - 5 micrometers and 8 - 14 micrometers. It has great optical properties and can pass infrared light well so infrared lenses can make images in these bands. Zinc sulfide is also a good infrared optical material. It's hard and stable chemically, so it's good for infrared imaging equipment that needs to be durable.

Different Imaging Effects

1. Ordinary Lenses
   The pictures from ordinary lenses have colors just like what we see with our eyes. When we take pictures of landscapes, we can see all the beautiful colors. And the contrast in these pictures comes from how different things reflect visible light. For example, a white thing and a black thing reflect different amounts of light, so they look different in the picture.

2. Infrared Lenses
   Infrared lens pictures are usually black and white. That's because infrared rays don't have color. The pictures are made from how strong the infrared rays from or reflected by things are. In infrared pictures, how bright something is shows how much infrared it gives off. For example, in infrared thermal imaging, things that are hot look brighter and things that are cold look darker. This is really useful for finding temperature differences or seeing things in low light or hidden places. For example, we can use it to find problems with industrial equipment or for military reconnaissance at night.

Different Application Scenarios

1. Ordinary Lenses
   Ordinary lenses are used a lot in our daily lives for taking pictures. We use them for taking pictures of people, landscapes, and for news photography. In commercial photography, we use them to take pictures of products to show off their features. In news reporting, journalists use them to quickly take pictures of what's happening.

2. Infrared Lenses
   Infrared lenses are used in special places where we need infrared. In security monitoring, when we use them with infrared lights, we can watch things all the time, day or night. In the medical field, they're used in thermal imaging equipment to find out where people are hot or cold to help doctors find diseases. In the military, they're used in night vision devices and infrared-guided weapons so soldiers can see and attack at night or in tough battlefield conditions.