The choice of the lens is significant for obtaining the desired results. You buy expensive cameras for nothing if the lens is poorly chosen. You will find in the camera features something called the "focal length of the lens", measured in millimetres. This value determines the opening angle of the camera (both horizontally and vertically). The smaller the focal length, the larger the camera angle. The longer the focal length, the smaller the camera angle. In the extreme situation of a 60mm lens, you can only cover a very narrow area but recognize small details at a distance.
Comparison of Surveillance Camera Lenses
The right angle depends on location to location. Still, as a general rule, if you have the thermal imaging security camera mounted close to the area you want to monitor, you will have to use a small focal length (large opening). If you mount the camera more from the area of interest, you will use a considerable focal length (small space and large zoom). Imagine that a camera with a long focal length is like binoculars. The greater the focal length, the greater the zoom effect.People usually want infrared cameras so that the cameras can see well at night. Let's explain how infrared technology works and how to proceed with quality images at night. Quality images at night depend not only on the infrared illuminator but also on the quality of the image sensor. More precisely, it would be best if you had a good collaboration between the IR illuminator attached to the thermal imaging security camera and the image sensor of it. The image sensor must know how to work with IR radiation to form clean images with well-defined objects and details in black and white.
An infrared camera needs a sensor optimized for IR light from the atmosphere. Just as during the day, the camera uses light from the sun to form images; an IR camera uses infrared light from the atmosphere at night. Because the IR radiation from the atmosphere is not always enough, the cameras have incorporated an infrared illuminator designed to "flood" the area of interest with infrared light. Those image sensors capable of working effectively with infrared radiation or a deficient light level are called image sensors with a "day/night" function.
Surveillance Camera with a Classic IR Projector
When natural light drops below a certain threshold, the IR illuminator is activated, and the image sensor uses infrared radiation to form a video image. The quality of the images (contrast, resolution, etc.) that the camera offers depends on the amount of IR radiation available and the quality of the image sensor. The images obtained at night using IR technology are black and white. During the day, the thermal imaging security camera produces colour images. When the amount of light drops below a set threshold, the camera automatically switches to IR mode with black/white photos.Once you have chosen a camera with a quality image sensor at night, it remains to "flood" the area of interest with sufficient IR radiation. That is done using IR illuminators integrated into the camera or IR projectors attached to the cameras. In the specifications of the thermal imaging security camera equipped with an IR illuminator, you will find the distance at which the camera can obtain images using the integrated IR illuminator. As installers of security systems recommend, you take that distance reluctantly. Generally, you will get the maximum efficiency at half the distance presented in the technical sheet.
Image Sensor as a Component
The image sensor is that component of a surveillance camera with the task of receiving the information carried by the light from the environment and transforming that information into electrical impulses to form a digital image. The image sensor is, therefore, the window through which the surveillance camera looks at the environment. And just as through a large window, you can see more things than through a small window, so a large image sensor will be able to receive more information than a small image sensor. So choose cameras with a larger image sensor.Standard sizes for image sensors start from ascending: 1/4", 1/3", 1/2.8", 1/2.5". The 1/4" size sensor is the smallest, and the 1/2.5" size sensor is large. You will most often find the sizes 1/4" and 1/3" for analogue cameras. Choose the 1/3" sensor between these two sizes. A larger sensor means more information captured and a higher resolution. For a thermal imaging security camera, you will find 1/2.5" or even 1/2" sensors with substantial frames, up to 4 times higher than an analogue camera.
The Right Camera for Quality Images
As pointed out in the previous point, you must also have an image sensor capable of providing quality images under infrared lighting conditions. Just because you have many IR LEDs in the room is needed. Until some time ago, the measure of the resolution of a camera was in "TV lines". A large number of TV lines represented an excellent resolution. Now, the resolution of a camera is measured directly digitally, in the number of pixels. The resolution describes the number of points that make up the image you see. The more points, the better, the richer the picture in detail.Now that you know what the right surveillance system for your home entails, look for a suitable thermal imaging security camera model and purchase it. Suppose you want to buy a device that covers a medium-sized yard completely. In that case, we recommend you go for a rotating version, which can cover 360 degrees and rotate automatically, visualizing the entire space in the centre of which it is mounted. Make sure you have the necessary equipment, tools and accessories at hand. You can usually find the complete list in the technical manual of the surveillance system.