The image visualized by a thermal camera is called thermography, and the high and low temperature areas of animals and substances are displayed in different colors.
Thermal cameras have a wide range of uses, such as structural diagnosis at construction sites, outdoor activities such as camping and mountaineering, crime prevention, and research. Helpful.
First, the principle of a thermal cameraIt is a natural phenomenon for human beings living on earth that objects become warm when exposed to sunlight.
William Herschel, an astronomer in the 1700s who tried to elucidate the mechanism, discovered that there is an invisible part of sunlight that can heat things.
The light has a wavelength outside (longer wavelength side) than red light, so it is named "infrared", and the light in the long wavelength range is called "far infrared". .
All matter on earth emits far infrared rays. And the higher the temperature, the greater the amount of far-infrared radiation (energy).
The thermal camera is equipped with a sensor that detects the far-infrared rays, and detects the temperature of the substance by detecting the strength of the far-infrared energy. The sensors used in thermal cameras are mainly microbolometers, which integrate small sensors called bolometers.
The far-infrared rays received from the object to be photographed enter the bolometer through the lens mounted on the camera, and the electric resistance value of the infrared absorption layer of the bolometer changes with temperature changes.
This change in electrical resistance is used to read the radiation intensity.
Items that indicate the performance of a thermal cameraThe items that indicate the performance of a thermal camera include the following, so it is a good idea to use them as criteria when choosing.
number of pixelsIt is the same as a pixel in a digital camera. The higher the number, the more distant and minute objects appear clearly.
angle of viewIt represents the horizontal x vertical angle of view. The larger the number, the wider the angle.
IFOVsThe smallest dimension of an object that the camera can detect.
For example, 11mrad can detect objects with dimensions of 11mm square. It is recommended to choose an IFOV that is 3 to 5 times the size of the actual object being photographed.
NETDIt is the temperature difference that the camera can detect.
The smaller the value, the less noise there is on the screen and the clearer the temperature difference will be.
focusThere are focus-free (fixed focus) and manual/autofocus (same as digital cameras).
The power of recent thermal camerasBecause the senses of beasts are sharper than the five senses of humans, there are many cases where the beasts sense our existence first.
In particular, wild boars are highly cautious and have a keen sense of smell similar to that of dogs.
However, thermal cameras can easily detect their presence and movement.
For example, if you shoot a wild boar about 30 meters away with a thermal camera with a resolution of 160 x 120 pixels, it will look like the video below. Also, if you shoot a wild boar from the sky with a drone equipped with a thermal camera with a resolution of 640 x 512 pixels, it will look like the video below.
Situations that can be used in hunting
In hunting, thermal cameras are most useful when looking for half-arrowed prey.
If it cannot be killed with one shot, the prey will often hide behind something and stay still.
In such cases, without a hound, even if the prey is bleeding, it is often difficult to find them.
However, if you have a thermal camera, you can search as long as you know the approximate direction in which you lost sight of your prey.
Traces of blood that has just flowed out are displayed in a different color than the surroundings, so you can expect to find them easily.
If you happen to encounter one, you have no choice but to deal with it appropriately (* Reference article: It is reassuring to have a "bear repellent" spray ), but the safest thing to do is to detect it early before it gets too close. run away.
However, if the target is completely hidden by trees, far-infrared rays will be blocked by the trees, making detection difficult.
If the subject is hidden by thick foliage, it can be seen if the foliage does not overlap double or triple, but it may not be suitable for hunting in areas where a lot of trees block the view. .
In addition, although a thermal camera can detect animals larger than a medium-sized dog, it may be difficult to detect small creatures such as birds (depending on the surrounding conditions and specifications). ).
Recommended thermal cameraThere are various types of thermal cameras, but here are some recommended thermal cameras that can be used for hunting.
Seek Thermal "Reveal pro EC"Seek Thermal's "Reveal pro EC" has specifications that can withstand actual battles, and is about the size of a mobile phone and easy to carry.
The published specs are 320 x 240 pixels, 32 degree angle of view, and a detection distance of about 550m.
The size is 12 x 6 x 3 cm, and the battery life is about 4 hours in normal mode.
In the video below, you can see how the thermal camera image changes as the target distance increases using Reveal pro EC.
The price is slightly higher at around 100,000 yen.
Caterpillar thermal camera equipped smartphone "CAT S60"
Caterpillar, a major construction equipment manufacturer, has released the CAT S60 smartphone equipped with a professional thermal camera.
Not only can it be used as a tool in the field, but even when used as a normal smartphone, it is guaranteed to attract attention for its solidity and functionality.
If you press the SOS button, you can send coordinate information and messages to pre-registered contacts, and it also has a built-in barometer, so it is also recommended for mountain hikers.
It has excellent waterproof and dustproof performance, as well as shock resistance that allows it to start up even after being immersed in water to a depth of 5 m for 60 minutes. * In the video below, I dropped it as much as I could and tested it.
The current price is less than 50,000 yen.
Seek Thermal "CompactPRO EC"A type that can be directly connected to your smartphone and operated is also on sale. Among them, Seek thermal's "CompactPRO EC" is equipped with a high-performance camera module that can withstand hunting.
The number of pixels is 320 x 240 pixels. Since it connects directly to your smartphone, there is no need to charge it, and you can use it immediately by downloading the app to your smartphone.
Images are saved on the smartphone, so you can immediately send still images and videos you have taken.
Of course, both for Android and iPhone are on sale, so choose the one that suits your smartphone.
summaryWith the evolution of technology, electronic devices are becoming more and more convenient and sophisticated.
Thermal cameras are also progressing, and the day may soon come when something convenient enough to replace hunting dogs will be released.
Many of them are reasonably priced, but they are compact in size and have a lot of features that gadget lovers will love.
For those who hunt with an excellent hound, or for experienced hunters who don't use half arrows, it may not be the right time to use it, but it will come in handy.