Press Release

Buying Guide: 3 Tips to Choose Your Thermal Imaging Lens

Mar. 31, 2022

With the development of thermal imaging technology, it has been more and more widely applied in diverse fields.

However, there is an obvious difference of thermal imaging lens requirements in different applications.

So how to choose the right thermal imaging lens for your intended application?

SUNNY INFRARED OPTICS will offer you several tips.

1. Select the lens type

It is important to take into account your intended application when assessing which thermal imaging lens is best suited.

Outdoor thermal imaging lens fall into two major types: handheld sights and rifle sights.

The lens of handheld sights is mainly used for target search, where manual lens with a wide imaging range is used. Based on the actual application environments, different sealing requirements should be taken into consideration. For rifle sights, side focus lens is commonly adopted when considering the ease of focusing. Side focus lens integrates the focusing structure into a knob to simultaneously improve the user experience and aiming accuracy. Besides, rifle sights lens need to be up to the shock resistance standard, so the structure is more complicated compared with the lens of handheld sights.

2. Get the right lens specs

For handheld sights, considering the observation range requirement, wide field lens is generally equipped.

For rifle sights, the corresponding focal length is generally decided according to intended detection distance. The longer the focal length, the farther the detection distance.

The following are the conventional specs for focal lengths, field of view, and detection distances.

fFOV(384*288 12μm)FOV(640*480 12μm)Distance
25mm10.5°(H)×7.9°(V)17.4°(H) ×13.1°(V)1km
50mm5.3°(H)×4.0°(V)8.8°(H) ×6.6°(V)2km

In addition to the focal length, coating is another important factor should be considered.

Sunny Infrared Optics can provide DLC, SDLC, HD, AR coating etc.

HD coating with higher comprehensive performance is usually used in handheld sights, while DLC coating with the best friction resistance is commonly used in rifle sights due to the extremely harsh application environments.

3. Confirm the lens structure

Size and weight are one of the most important specifications of Outdoor camera. In hence, it requires a lighter and more compact design on lens.

In order to reduce the weight of thermal camera, aluminum alloy or magnesium alloy is usually applied to the material of the lens structure.

Meanwhile, due to its particularity of the detector structure, it is necessary to provide the focal-plane position as well as mount size of the detector to the lens manufacturer, so as to evaluate the back focal length and the mount size of the lens.


The top three hot-selling outdoor thermal imaging lenses are listed below for your reference.

SUNNY INFRARED OPTICS can provide various of thermal imaging lens solutions.

If you have further requirements, feel free to contact us anytime

Buying Guide: 3 Tips to Choose Your Thermal Imaging Lens

+86 574 6253 0985


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Keywords: Thermal Imaging