When buying a cheap night vision camera, it is essential to look at the specifications. However, a lot of people talk about specifications but they do not understand what they actually mean. It can be very confusing if you are looking for your first-night vision device or you just bought your first device and you have to figure out the specs.
Your head could be spinning right now with all the night vision jargon such as mounts, housing, helmets, shrouds and accessories. Everyone gets confused for the first time until they get a little help.
IR resolution
The resolution of a camera is the clarity of a subject. The resolution is directly related to the total number of pixels of the camera. The more pixels, the higher the resolution. There are three main standards for resolution. There is the low resolution, the medium resolution and the high resolution.
The resolution required will depend on your application. For example, if you are working on high-risk things like electrical equipment then you may want to choose a higher-resolution camera to maintain a sharp image whilst investigating potential issues.
Thermal sensitivity
It is also very important to consider the thermal sensitivity of the camera before buying. Thermal sensitivity is how sensitive a camera is to changes in temperature. Thermal sensitivity will affect the clarity of the image. The more sensitive your night vision equipment is, the greater the definition between cold and hot areas will be. On the other hand, you will experience more blurring when the sensitivity is low.
Field of view
This is another thing you want to consider when buying your thermal imaging camera. The field of view of a thermal camera is determined by the lens of the camera and defines the area that the imager sees at any given moment. The combination of the lens, sensor size, and distance to the object will determine the smallest area that your imager discerns.
The field of view is usually expressed in angular degrees. If you need to measure an object from a distance then you will need a camera with a small field of view. If you measure up close to objects then a thermal camera that has a wider field of view will do fine.
Distance-to-spot ratio
This is the relationship between the size of an area and the camera’s distance from the area. The area of the surface measured grows at a specific rate as the total distance increases, depending on the ratio.
Emissivity
This is the measure of how well something emits energy as radiation. It is a scale of zero to one with zero being the perfect reflector of light while one being an object that does not reflect light at all. A lot of items fall within an emissivity range of about 0.95.
When choosing a cheap night vision camera, your selection will depend on the surfaces you want to measure. For example, some cameras have an emissivity that can be adjusted from 0.01 to 1 whilst others have pre-set selections.