Glossary
Not sure what the technical terms mean? You will find the answers here.
Also called AI upscaling. Using complex algorithms, “artificial intelligence” vectorises the sensor image during digital zoom, reinterprets it and displays it on the screen at a higher resolution, so that pixelation of the image is significantly reduced.
Amorphous silicon — a semiconductor material from which microbolometers can be made. Comparatively easy to manufacture and process, but the sensors age, are not resistant to sunlight and are unsuitable for high thermal resolutions below 40 mK.
Spacer of varying thickness between the mounting clamp and the thermal imaging device, used to adjust its optical axis height.
See collimation
For thermal imaging devices, the angle in radians at which a single sensor pixel appears, taking the objective optics into account. A measure of calculated precision.
Image intensifier; see image intensifier
Amplification of the emphasis on heat differences in the image. Usable images can still be produced even with very little thermal contrast, where nothing would be visible with normal filters.
The ability of an OLED in a thermal imaging device to reproduce the image brightly enough in high ambient light (for example sunshine) and, at night, with minimal brightness while still providing sufficient contrast. Very few OLEDs can meet both requirements and are clearly too bright at night, which is why a device should always be tested at night as well.
The process of adjusting the optical axis of an inline device to the optical axis of the sight. Strictly necessary when the inherent magnification of the inline device is greater than 1.0x, in order to be able to shoot precisely. With thermal imaging devices, the image on the device’s OLED is shifted electronically horizontally and vertically by whole pixels until the centre of the displayed image coincides with the optical axis.
The part of a thermal imaging device or image intensifier facing the user’s eye, in which the OLED or phosphor screen is visible. It can be optimised for different purposes such as observation, use as an inline device and so on.
Ratio of the focal length to the objective diameter. The reciprocal of the lens speed, dimensionless. At values above 1.0, the thermal radiation arriving at the microbolometer is no longer strong enough and produces a poorer image than would be technically possible.
Processing of the sensor signal for a corresponding image display. Monochrome and multicolour filters are common. Red filters are easy on the eyes and particularly pleasant for night use, but rarely found.
Distance between the principal plane of an optical lens and the focus or focal point. The microbolometer is usually located there.
A measure of the number of images per second. Both the microbolometer and the OLED have their own maximum frame rate; the highest values are currently 60 Hz. A value is often stated, but what exactly it refers to usually remains unclear. The highest possible values are preferable in order to prevent the image from lagging during the user’s own movement. The latency of the OLED also plays a significant role.
Image intensifier tube, image intensifier tube.
Analogue device that amplifies residual light present in the field of view to a level perceptible to the human eye and displays the surroundings in the field of view brightened. Insufficient residual light drastically reduces range and image quality and can only be compensated for by artificial illumination or, to a limited extent, by higher-grade tubes.
Combination of an image converter and a secondary electron multiplier that converts incoming photons into electrons, multiplies them and displays them on a phosphor screen. The heart of image intensifiers.
A measure of the image size of a raster graphic; for thermal imaging devices, related to the OLED. The resolution must match the resolution of the microbolometer, the design, the mode of operation and the eyepiece optics. The absolute size is of little relevance, but is often used to create an impression.
Definition of the degree of protection of electronic devices and their housings according to DIN VDE 0470-1 and EN 60529. The first digit indicates protection against foreign bodies: 6 is the highest level and the only one that is “dust-tight”. The second digit indicates protection against the ingress of water: 8 is the highest level and the only one that is “permanently watertight”. An X means that no statement has been made. IPX7, for example, is not dust-protected and is only protected against brief immersion in water.
A thermal imaging device or image intensifier mounted on or in front of the objective of a riflescope, spotting scope and so on. Note that thermal imaging devices can only be used in front of optics, because their glass lenses block thermal radiation.
A measure of the time that elapses between a change in the signal arriving at a sensor and the signal output.
Ratio of the objective diameter to the focal length. The reciprocal of the f-number, dimensionless. At values below 1.0, the thermal radiation arriving at the microbolometer is no longer strong enough and produces a poorer image than would be technically possible.
See STANAG 2324
Electronic: see zoom
Optical: the ratio of the apparent visual angle of an object in the optical instrument to the visual angle at which the object appears to the human eye. Also: the ratio of the focal length of the objective to the focal length of the eyepiece.
Optical: the ratio of the apparent visual angle of an object in the optical instrument to the visual angle at which the object appears to the human eye. Also: the ratio of the focal length of the objective to the focal length of the eyepiece.
Semiconductor sensor, the heart of a thermal imaging device. Long-wave infrared radiation heats the sensor and is measured pixel by pixel. Ultimately, the temperature differences of the objects in the field of view are measured and displayed relative to one another, while the self-heating of the microbolometer has to be filtered out. Various resolutions up to 640×512 pixels are available; more pixels provide better resolution, but also consume more energy and cost more.
Adapter with which accessories such as sights, inline devices, bipods, sling swivels and so on can be attached to weapons or to other accessories.
Night vision device; see image intensifier
Carbon nanotubes, also CNT, are microscopically small tubular structures made of carbon. Nanotubes can be mixed with conventional plastic, which improves the mechanical properties of the plastics.
Organic light-emitting diode; here, the term for a particularly energy-efficient screen used to display the sensor image of a thermal imaging device. Important values include minimum and maximum brightness, power consumption and latency. Latency is a measure of how far the image lags behind during the user’s own movement, but it is almost never stated. See also image resolution.
The part of a thermal imaging device or image intensifier facing the object being viewed. It directs the incoming thermal radiation onto the microbolometer, or residual light into the image intensifier tube, and produces a real optical image. Large diameters mean high performance, but also high cost. Zoomable objectives are not practical because of the enormous transmission losses.
Height of the optical axis of a riflescope, spotting scope, thermal imaging device or image intensifier above a reference line; here: above the top of the Picatinny rail.
The Picatinny rail is a cross-slotted rail for the fast and repeatable mounting of accessories on firearms and similar equipment. It is available in two standards: the older STANAG 2324 (= MIL-STD-1913) and the current STANAG 4694.
The area that a single sensor pixel of a thermal imaging device covers geometrically at a distance of 100 m, taking the objective into account. Not to be confused with angular resolution, which is calculated differently; the difference is negligible because it is very small. A measure of calculated precision.
Distance from the centre of one pixel to the centre of the neighbouring pixel on a microbolometer. The most recent value is 12 µm; 17, 25 and even 40 µm used to be common. Smaller values increase image noise, but also resolving power, which is why they are preferable.
A value indicating the theoretical accuracy of a thermal imaging device. Without further electronic intervention it is identical to the pixel coverage. In practice, both larger and significantly smaller dispersion circles are achieved. Sub-pixel collimation can double the precision.
An image intensifier mounted on or behind the eyepiece of a riflescope, spotting scope and so on. Note that the reduction in light transmission of the optics placed in front has a negative effect, and that eye relief must be taken into account, meaning the sighting optic has to be moved further forward.
Specification of a maximum calibre, or of a maximum permissible projectile energy at a specific pulse duration, that a thermal imaging device or image intensifier mounted on or to a firearm is certified to withstand as a shock load. Electronics, sensors, seals and the power supply are in some cases exposed to accelerations of more than 1200 g, for which very few units are approved. Because weapon characteristics and weight, among other factors, play a major role, the highest permissible values possible should be looked for here.
If weapon accessories such as sights or inline devices are attached in exactly the same position as before when they are removed and mounted again, shifts in the point of impact are prevented. Absolute repeatability is technically achievable, but rarely encountered, because the mounts and their counterparts are often not manufactured precisely enough.
NATO’s own standard for the Picatinny rail, which has defined it since about 1995. It is based on the imperial system. The STANAG 4694 is more repeatable.
NATO’s own standard for the Picatinny rail, which since 2009 has defined the most recent form of the Picatinny rail and replaces STANAG 2324. Specifically, it refers to the metric system, halves the tolerances and redefines the contact surfaces, which significantly increases repeatability for products that conform to the standard.
Particularly precise collimation in which the image can be shifted by half a pixel. Also called SPC. It halves the dispersion of the device, or doubles its precision. Available worldwide from only a single manufacturer.
Also called a thermal camera or thermal imager: a device that can detect thermal radiation in the surroundings, process it into an image and display it. Always digital by nature.
The ability of the microbolometer to detect temperature differences between objects. It is adversely affected by the objective, depending on its quality. The smaller the value, the better. 40 mK means that a temperature difference of 0.04°C can be detected by the sensor and displayed.
A measure of how quickly the microbolometer can detect changes in incoming thermal radiation. For the devices in our range, between 7 and 12 ms. Similar to latency.
Vanadium oxide — a semiconductor material from which microbolometers can be made. Very complex and difficult to manufacture and process, but insensitive to ageing and sunlight and suitable for high thermal resolutions below 20 mK.
Magnification of a digital kind, always accompanied by pixelation of the image. Reducing this deterioration of the image is only possible with considerable effort, but it is worthwhile; see AI upscaling. Available worldwide from only a single manufacturer.