Can Thermal Optics Be Used During the Day?
When you think of thermal optics, you might picture nighttime hunting or firefighters scanning for hotspots in smoke-filled buildings. But what about daytime use? Can these special devices really work when the sun is shining bright? Let’s break it down.
Understanding Thermal Optics
Thermal optics, also known as thermal imaging, capture heat instead of visible light. They can show differences in temperature, revealing things we can’t see with our eyes. Imagine standing outside on a sunny day and feeling warm pavement under your feet. Thermal optics see that heat, making hidden threats or targets clear.
Daytime Limitations
Now, here’s the catch. When the sun’s out, thermal optics can face some challenges. Bright sunlight can produce a lot of heat, which might drown out the smaller temperature differences that these devices are designed to detect. Think of it like trying to spot a small boat in a big ocean—everything just looks like water. This can make it harder to spot people or animals, especially if they’re resting in the sunshine.
The Bright Side of Using Thermal Optics by Day
Despite these challenges, thermal optics can absolutely be used during the day. They can help spot heat signatures that are still cooler than their surroundings. For example, if someone is hiding in the shade on a hot day, their body heat can stand out against the cooler ground.
Great for Security and Surveillance
In security and surveillance, using thermal optics during the day can be incredibly useful. Security teams can spot intruders attempting to breach a property while taking advantage of shaded areas. Just like a detective piecing together clues, these tools can reveal critical details that the naked eye might miss.
Wildlife Observation
Nature lovers also benefit from daytime thermal optics. Watching animals without disturbing them can be easier with these devices. Imagine quietly observing a deer resting under a tree while the sun beats down around it. With thermal optics, you can spot that deer without getting too close or causing it to flee.
Choosing the Right Equipment
If you decide to use thermal optics during the day, it’s essential to pick the right equipment. Some thermal devices are designed to work better in daylight than others. They might have advanced features, like enhanced image processing, allowing them to filter out background heat and focus on what matters. It’s a bit like having the right glasses to see better, whether it’s sunny or cloudy.
Important Info Regarding Thermal Optics
This notice provides important safety and handling information regarding thermal imaging devices and their infrared detector (sensor core). Please read this information carefully before operating your device.
Thermal imaging devices utilize highly sensitive infrared detectors designed to capture subtle temperature differences. Due to their sensitivity, these detectors may be affected by exposure to high-intensity thermal radiation.
Infrared Detector Protection
The infrared detector may be permanently damaged by exposure to high-radiation targets.
Even brief exposure — including momentary scanning — of hot objects, open flames, the sun, solar reflections, lasers, or other high-energy thermal sources may cause irreversible pixel damage or sensor degradation.
Users should avoid direct or transient exposure to high-intensity thermal sources at all times.
Lens Cap Protection and User Acknowledgment
Each device is shipped with a protective lens cap intended to help shield the sensor from exposure to high-radiation sources during storage and transport.
Removal of the lens cap indicates that the user acknowledges these risks and agrees to operate the device in accordance with recommended safety and operating guidelines.
Initial Inspection and Operating Conditions
Upon receiving the device, initial inspection and functional testing should be performed:
Ensure that no high-temperature objects, direct sunlight, or strong reflective heat sources are present during initial operation.
Factory Handling Conditions
Thermal imaging devices are inspected and tested under controlled manufacturing conditions. Products are not exposed to damaging levels of thermal radiation during normal production, assembly, or standard shipping processes.
Warranty and Limitation of Liability
Damage to the infrared detector resulting from exposure to high-temperature targets, intense thermal radiation, or operation outside recommended conditions is considered external or misuse-related damage rather than a defect in materials or workmanship.
Such damage may include, but is not limited to:
To the extent permitted by applicable law, this type of damage is not covered under standard limited warranties.
User Responsibility
The user is responsible for operating the device in accordance with all applicable instructions, warnings, and safety guidelines. Failure to follow these precautions may result in immediate and irreversible damage to the sensor.
These precautions reflect standard industry practices applicable to thermal imaging devices.
Conclusion
In conclusion, thermal optics can be a valuable tool during the day, despite the challenges posed by sunlight. With the right gear, you can still spot important heat signatures that make a huge difference in fields like security and wildlife observation. So, yes, you can definitely use thermal optics during the bright hours—just know how to get the most out of them!
How Does Thermal Optics Work for Hunting?
Thermal optics work by detecting and visualizing the heat emitted by objects, making them invaluable tools for hunting, especially in low-light or nighttime conditions. These devices utilize infrared sensors to capture thermal radiation, which is emitted by all objects with a temperature above absolute zero. When a hunter looks through a thermal optic, the device converts this thermal energy into a visible image, allowing the user to see living creatures that might otherwise be camouflaged in their environment.
The resulting images display various colors based on temperature differences—typically warmer objects appear brighter or in different shades than cooler surroundings—enabling hunters to easily distinguish between game and background foliage. Additionally, modern thermal optics often come equipped with features such as zoom capabilities and digital enhancements that improve visibility even further. By providing an effective way to detect heat signatures, thermal opticsenhance hunting success rates while also promoting safer practices during nocturnal outings.
Is It Legal to Hunt with a Thermal Scope?
Hunting has deep roots in human history, and with technology, it keeps evolving. One of the hottest topics is the use of thermal scopes. But is it legal to hunt with these devices? Let’s break it down.
What Is a Thermal Scope?
A thermal scope is a tool that lets hunters see heat signatures. It’s like seeing in the dark, but instead of light, it uses heat. This helps hunters spot animals even when it’s pitch black outside. Imagine trying to spot a deer at night; a thermal scope makes that job easier and safer.
Legality Varies by Location
Laws about hunting with thermal scopes are not the same everywhere. Each state or country has its own rules. In some places, it's perfectly fine; in others, it might be illegal or restricted. Why does it matter? Because what’s legal in one area might get you in trouble in another. So, always check local laws before heading out.
Why Some States Allow Thermal Scopes
You might wonder why some states embrace thermal scopes while others don’t. The main reasons often include safety, population control, and wildlife management. By allowing these scopes, states aim to reduce the number of accidents in the field. Plus, it can help manage animal populations effectively.
Ethical Considerations
Thinking about the ethics of hunting with thermal scopes is essential. Some believe that using high-tech gear gives hunters an unfair advantage. Others argue it promotes responsible hunting by improving safety and efficiency. This debate can be a lot like a game of chess—strategic but often subjective. It's all about finding a balance between technology and tradition.
The Future of Hunting Technology
As technology advances, the conversation about thermal scopes will continue. More hunters are using these devices, leading to discussions about regulations and ethics. It's like riding a bike—you have to learn how to balance while also keeping an eye on the road ahead.
Conclusion
So, is it legal to hunt with a thermal scope? The answer isn’t simple. It varies by location, regulations, and personal ethics. If you're passionate about hunting, stay informed about the laws in your area. This will help ensure that your hunting experiences are not only enjoyable but also lawful and responsible. Always check before you go out, just like you'd want to make sure your bike tires are full before a ride!
Is Night Vision & Thermal Legal?
Yes, in the United States, U.S. citizens and permanent residents are allowed to own and use night vision and thermal optics. However, it's illegal to take these devices outside the country without specific approval and proper licensing from the U.S. State Department. These devices are regulated under the International Traffic in Arms Regulations (ITAR) to ensure they don't end up in the wrong hands. If you have any questions or need further clarification, we are happy to assist.
Do you ship optics outside of the United States?
Most night vision and thermal devices are regulated under ITAR, making it illegal to export them. While a few items may be eligible for export, our strict policy is to only ship our products within the United States, with no exceptions. This ensures the safety and protection of our service members.
What is ITAR?
ITAR stands for International Traffic in Arms Regulations. It is a set of U.S. government regulations that control the export and import of defense-related articles, services, and technology. Managed by the U.S. Department of State, these regulations are designed to ensure that defense-related technology does not fall into the hands of foreign nations or entities that could threaten U.S. national security or that of its allies.
Here are the key aspects of ITAR:
- Defense Articles and Services: ITAR regulates the export of military equipment, weapons, and technical data related to defense articles. This includes not only physical items like firearms and missiles but also technical data, designs, software, and services related to their production.
- U.S. Munitions List (USML): The USML is a detailed list of items and technologies subject to ITAR. It includes everything from firearms, military vehicles, and aircraft to certain satellite technology and software used in defense applications.
- Export and Licensing: U.S. companies and individuals must obtain an export license from the U.S. Department of State before exporting or sharing ITAR-controlled items or technical data with foreign entities, including foreign employees working within the U.S.
- Penalties: Violations of ITAR can result in severe penalties, including fines, loss of export privileges, and criminal charges. Companies and individuals must take extensive precautions to avoid unauthorized access or sharing of ITAR-controlled items.
- Foreign Nationals: Even sharing technical information with a foreign national within U.S. borders can be considered an export under ITAR, requiring special permission.
ITAR applies to industries like defense contractors, aerospace, satellite communications, and even certain high-tech companies dealing with military or space technology.
What is EAR Regulations?
EAR stands for the Export Administration Regulations, a set of regulations administered by the U.S. Department of Commerce through its Bureau of Industry and Security (BIS). EAR governs the export of dual-use goods, software, and technology, which are items that have both civilian and military applications but are not primarily intended for military use.
Here are the key aspects of the EAR:
- Dual-Use Items: EAR controls items that have both commercial and military uses. This includes a broad range of products and technologies, such as electronics, computers, encryption software, chemicals, and manufacturing equipment. These items can be used in a variety of industries, from telecommunications to aerospace, but they also have potential military or security applications.
- Commerce Control List (CCL): The CCL is a key part of the EAR. It is a detailed list that categorizes items subject to control under the EAR based on their technical characteristics, end-use, and potential destinations. Items on the CCL are assigned an Export Control Classification Number (ECCN), which determines the level of control and whether a license is needed for export.
- Export Licenses: Under the EAR, exporters may need to obtain a license to export certain items to specific countries or entities. Whether a license is required depends on factors like the destination country, the end-use of the product, and the identity of the end-user. BIS issues export licenses and evaluates each case based on U.S. national security, foreign policy, and economic objectives.
- Deemed Exports: Similar to ITAR, the EAR regulates "deemed exports," which refers to the release of controlled technology or software to foreign nationals within the U.S. This can happen through technical discussions, training, or visual access, and may require a license.
- License Exceptions: There are several exceptions to licensing requirements under the EAR. Some items, even if they fall under the CCL, may not require a license if they meet specific criteria for exceptions such as being for certain types of consumer use or for export to allied countries.
- Penalties: Violations of the EAR can result in civil penalties, criminal charges, and hefty fines, similar to ITAR. Companies and individuals are responsible for ensuring that they comply with EAR regulations, including conducting due diligence on end-users and destinations.
- Scope: The EAR covers a wide array of industries, especially those involved in advanced technologies like semiconductor manufacturing, artificial intelligence, encryption, and telecommunications, as well as more traditional sectors such as chemicals and materials.
In summary, while ITAR primarily focuses on military and defense-related exports, EAR regulates the broader category of dual-use items, which includes civilian technologies that could have military or security applications.
More about ITAR/EAR Regulations here -
https://nightvisionuniverse.com/pages/itar-ear-compliance-the-international-traffic-in-arms-regulations-itar-export-administration-regulations-ear
AUTOMATIC BRIGHTNESS CONTROL (ABC)
An electronic feature that automatically reduces voltages to the Microchannel Plate to keep the image intensifier’s brightness within optimal limits and protects the tube. The effect of this can be seen when rapidly changing from low-light to high-light conditions; the image gets brighter and then, after a momentary delay, suddenly dims to a constant level.
AUTO-GATED POWER SUPPLY
When the power supply is “Auto-Gated,” it means the system is turning itself on and off at a very rapid rate. This, combined with a thin film attached to the Microchannel plate (an ion barrier) reduces blooming. While “blooming” can be noticeably less on systems with a thin film layer, systems with thicker film layers can be perfectly acceptable depending on the end user’s application. Deciding which night vision goggle is better should not be based solely on blooming.
BLACK SPOTS
These are common blemishes in the image intensifier of the NVD or can be dirt or debris between the lenses of the NVG. Black spots that are in the image intensifier do not affect the performance or reliability of a night vision device and are inherent in the manufacturing processes. Every night vision image intensifier tube is different.
Dark Spots / Blemishes (Normal in Image Intensifier Tubes)
Image intensifier tubes used in PVS-14 and similar night-vision systems may show small fixed dark spots when looking through the device. These spots are not dirt, damage, or signs of use — they are a normal cosmetic occurrence in the photocathode/MCP manufacturing process.
Every major tube manufacturer — including Elbit Systems of America (MX-11769 / MX-10160) — and U.S. Military technical documentation states:
“Black spots are acceptable and normal unless they interfere with the field of view or exceed the spot-size/zone limits.”
Tubes are inspected and graded using a zone chart:
• Zone 1 (center) – most strict (usually 0–1 tiny spot allowed)
• Zone 2 (mid ring) – minor cosmetic spots allowed
• Zone 3 (outer edge) – relaxed tolerance
Only tubes that meet the factory spot-allowance specification are released.
These spots do NOT affect performance or brightness.
BIOCULAR
Viewing a single image source with both eyes (example: watching a television set).
BINOCULAR
Viewing a scene through two channels; i.e. one channel per eye.
BLOOMING
Loss of the entire night vision image, parts of it, or small parts of it, due to intensifier tube overloading by a bright light source. Also, known as a “halo” effect, when the viewer sees a “halo” effect around visible light sources. When such a bright light source comes into the night vision device’s view, the entire night vision scene, or parts of it, becomes much brighter, “whiting out” objects within the field of view. Blooming is common in Generation 0 and 1 devices. The lights in the image to the right would be considered to be “blooming”.
BRIGHT-SOURCE PROTECTION (BSP) – HIGHLIGHT CUT-OFF
An electronic function that reduces the voltage to the photocathode when the night vision device is exposed to bright light sources such as room lights or car lights. BSP protects the image tube from damage and enhances its life; however, it also has the effect of lowering resolution when functioning except for the Pinnacle Autogated Units which maintain the systems resolution.
BORESIGHTING
The alignment of a weapon-aiming device to the bore of the weapon. See also Zeroing.
C-MOUNT
A standard still and video camera lens thread size for mounting to the body of a camera. Usually 1/2″ or 3/4″ in diameter.
COMSPEC (COMMERCIAL SPECIFICATION)
A term used to describe image tube quality, testing and inspection done by the original equipment manufacturer (OEM).
CHICKEN WIRE
An irregular pattern of dark thin lines in the field of view either throughout the image area or in parts of the image area. Under the worst-case condition, these lines will form hexagonal or square wave-shape lines.
DAYLIGHT LENS COVER
Usually made of soft plastic or rubber with a pinhole that allows a small amount of light to enter the objective lens of a night vision device. This should be used for training purposes only and is not recommended for an extended period of time. Near field focus only usable in this fashion.
DAYLIGHT TRAINING FILTER
A glass filter assembly designed to fit over the objective lens of a night vision device. The filter reduces light input to a safe (night-time) level, allowing safe extended daytime use of the night vision device.
DISTORTION
There are two types of distortion found in night vision systems. One type is caused by the design of the optics, or image intensifier tube, and is classical optical distortion. The other type is associated with manufacturing flaws in the fiber optics used in the image intensifier tube.Classical Optical Distortion: Classical optical distortion occurs when the design of the optics or image intensifier tube causes straight lines at the edge of the field of view to curve inward or outward. This curving of straight lines at the edge will cause a square grid pattern to start to look like a pincushion or barrel. This distortion is the same for all systems with the same model number. Good optical design normally makes this distortion so low that the typical user will not see the curving of the lines.
Fiber Optics Manufacturing Distortions: Two types of fiber optics distortions are most significant to night vision devices: S-distortion and shear distortion:
S-Distortion: Results from the twisting operation in manufacturing fiber-optic inverters. Usually S-distortion is very small and is difficult to detect with the unaided eye.
Shear Distortion: Can occur in any image tube that uses fiber-optic bundles for the phosphor screen. It appears as a cleavage or dislocation in a straight line viewed in the image area, as though the line were “sheared”.
EQUIVALENT BACKGROUND ILLUMINATION (EBI)
This is the amount of light you see through a night vision device when an image tube is turned on but no light is on the photocathode. EBI is affected by temperature; the warmer the night vision device, the brighter the background illumination. EBI is measured in lumens per square centimeter (lm/cm2). The lower the value the better. The EBI level determines the lowest light level at which an image can be detected. Below this light level, objects will be masked by the EBI.
EDGE GLOW
There is a defect in the image area of the NVG. Edge glow is a bright area (sometimes sparkling) in the outer portion of the viewing area.
EMISSION POINT
A steady or fluctuating pinpoint of bright light in the image area that does not go away when all light is blocked from the objective lens. The position of an emission point within the field of view will not move. If an emission point disappears or is only faintly visible when viewing under brighter nighttime conditions, it is not indicative of a problem. If the emission point remains bright under all lighting conditions, the system needs to be repaired. Do not confuse an emission point with a point of light source in the scene being viewed.
EYE RELIEF
The distance a person’s eyes must be from the last element of an eyepiece in order to achieve the optimal image area.
FIELD-OF-VIEW
The diameter of the imaged area when viewed through an optic
FIGURE OF MERIT (FOM)
Image Intensification tube specification designation, calculated on line pair per mm x signal to noise.
FIXED-PATTERN NOISE (FPN)
A faint hexagonal (honeycomb) pattern throughout the image area that most often occurs under highlights conditions. This pattern is inherent in the structure of the Microchannel plate and can be seen in virtually all Gen 2 and Gen 3 systems if the light level is high enough.
FOOTLAMBERT (FL)
A unit of brightness equal to one footcandle at a distance of one foot.
GAIN
Also called brightness gain or luminance gain. This is the number of times a night vision device amplifies light input. It is usually measured as tube gain and system gain. Tube gain is measured as the light output (in fL) divided by the light input (in fc). This figure is usually expressed in values of tens of thousands. If tube gain is pushed too high, the tube will be “noisier” and the signal-to-noise ration many go down. U.S. military Gen 3 image tubes operate at gains of between 20,000 and 45,000. On the other hand, system gain is measured as the light output (fL) divided by the light input (also fL) and is what the user actually sees. System gain is usually seen in the thousands. U.S. military systems operate at 2,000 to 3,000. In any night vision system, the tube gain is reduced by the system’s lenses and is affected by the quality of the optics or any filters. Therefore, system gain is a more important measurement to the user.
GALLIUM ARSENIDE (GAAS)
The semiconductor material used in manufacturing the Gen 3 photocathode. GaAs photocathodes have a very high photosensitivity in the spectral region of about 450 to 950 nanometers (visible and near-infrared region).
GENERATIONS
Two technologies are referenced as night vision; image intensification and thermal imaging (see definitions). Because of cost and the fact that image intensifier scenes are easier to interpret than thermal (thermal images show targets as black or white – depending upon temperature – making it more difficult to recognize objects), the most widely used night vision aid in law enforcement is image intensification (l²) equipment. To date, there have been four generations of l² devices, identified as Gen 0, Gen 1, Gen 2, and Gen 3. Developmental laboratory work is on going, and the U.S. military may designate the resulting as Gen 4. However, no definition for Gen 4 presently exists.
HALO
Halo is the circular region around a bright light that appears “brighter” – It’s caused by elastic collisions of electrons with the MCP surface which subsequently then bounce off and down another hole. Halo’s are the same size all over the screen and the size is dictated by the distance between the photocathode and the MCP. Basically, it’s the round circle around lights when you look at them with Night Vision and it’s generally used as an indication that you’re looking at something that’s too bright
HIGHLIGHT SHUTOFF
An image intensifier protection feature incorporating a sensor, microprocessor and circuit breaker. This feature will turn the system off during periods of extreme bright light conditions.
INTERPUPILLARY ADJUSTMENT
The distance between the user’s eyes (pupils) and the adjustment of binocular optics to adjust for differences in individuals. Improperly adjusted binoculars will display a scene that appears egg-shaped or as a reclining figure-8.
INTERPUPILLARY DISTANCE
The distance between the user’s pupils (eyeball centers). The 95th percentile of US military personnel falls within the 55 to 72mm range of IPD.
IR ILLUMINATOR
Many night vision devices incorporate a built-in infrared (IR) diode that emits invisible light or the illuminator can be mounted on to it as a separate component. The unaided eye cannot see IR light; therefore, a night vision device is necessary to see this light. IR Illuminators provide supplemental infrared illumination of an appropriate wavelength, typically in a range of wavelengths (e.g. 730nm, 830nm, 920nm), and eliminate the variability of available ambient light, but also allow the observer to illuminate only specific areas of interest while eliminating shadows and enhancing image contrast.
IR LASER
High-power devices providing long-range illumination capability. Ranges of several thousand meters are common. Most are not eye-safe and are restricted in use. Consult FDA CFR Title 21 for specific details and restrictions.
IR LASER VS. IR ILLUMINATOR
IR lasers will pinpoint a location that can only be seen through night vision devices. Mostly used for target acquisition for others to see.
IR illuminators will illuminate the target within so many feet kinda like a flashlight that can only be seen through night vision. Mostly used for the person using the IR illuminator to help see and make an accurate shot on the target.
IR (INFRARED)
Area outside the visible spectrum that cannot be seen by the human eye (between 700 nanometers and 1 millimeter). The visible spectrum is between 400 and 700 nanometers.
ITAR (INTERNATIONAL TRAFFIC IN ARMS REGULATIONS)
ITAR represents a set of US Government regulations that control the export of defense-related materials, articles, and services on the United States Munitions List. These regulations implement the provisions of the Arms Export Control Act, and are described in Title 22 (Foreign Relations), Chapter I (Department of State), Subchapter M of the Code of Federal Regulations. The Department of State Interprets and enforces ITAR. Its goal is to safeguard US National Security and further US Foreign Policy objectives. Basically, ITAR dictates that any defense related items (including Night Vision Equipment and IR Equipment) cannot be exported from the United States in any way, without express permission from the US Department of State. Failing to follow ITAR will result in felony charges which can lead to heavy fines and/or prison sentences.
LASER RANGEFINDER
This allows you to measure distance to objects. Designed to determine the exact distance between the observer and the target. Measurement results are displayed on the scopes monitor.
LED (LIGHT-EMITTING DIODE)
LED’s are electronic light sources based on the semiconductor diode. When the diode is forward biased, electrons recombine with holes, releasing energy in the form of light. This is called Electroluminescence. The color of the light is determined by the energy gap of the semiconductor. LED’s have many advantages over traditional incandescent light sources including lower energy consumption, longer lifetime, more robustness, smaller size, and faster switching.
LP/MM (LINE PAIRS PER MILLIMETER)
Units used to measure image intensifier resolution. Usually determined from a 1951 U.S. Air Force Resolving Power Test Target. The target is a series of different-sized patterns composed of three horizontal and three vertical lines. A user must be able to distinguish all the horizontal and vertical lines and the spaces between them. Typically, the higher the line pair, the better the image resolution. Generation 3 tubes generally have a range of 64 – 72 lp/mm, although line pair measurement does not indicate the generation of the tube. Some Generation 2+ tubes measure 28-38 lp/mm, (Gen 2 SHP at 54-59 lp/mm typically), while a Generation 1+ tube may have measure at 40 lp/mm.
LUMEN
Denotes the photons perceptible by the human eye in one second.
MONOCULAR
A single channel optical device.
NATO-STANAG
Term for the North Atlantic Treaty Organization STANdard AGreement. This can be described as an international MILSPEC
MA/W (MILLIAMPS PER WATT)
The measure of electrical current (mA) produced by a photocathode when exposed to a specified wavelength of light at a given radiant power (watt).
MCP (MICROCHANNEL PLATE)
A metal-coated glass disk that multiplies the electrons produced by the photocathode. An MCP is found only in Gen 2 or Gen 3 systems. MCPs eliminate the distortion characteristic of Gen 0 and Gen 1 systems. The number of holes (channels) in an MCP is a major factor in determining resolution. ITT Industries’ MCPs have 10.6 million holes or channels compared to the previous standard of 3.14 million.
MICRON (PIXEL PITCH)
The thermal sensor's micron or (pixel pitch) is a measurement of the spacing between each pixel in the digital picture. The unit of measurement is a micrometer, sometimes known as a micron. The best thermal optics are now those with a thickness of 12 to 17 microns. The lower the micron the better.
MICROWATTS (UW)
A microwatt is equal to one millionth of a watt. A watt is a derived unit of power in the International System of Units (SI) and measures the rate of energy conversion. One watt is equivalent to 1 joule of energy per second.
MIL-DOTS
The Mil-Dot reticle was designed around the unit of measurement called the miliradian. The dots of a mil-dot reticle allow the shooter to estimate range to a target of a known size, hold over targets with the mil-dots as a reference, and give a recognizable lead for moving targets. The US Army equates each mil to 3.375 MOA while the US Marines equate it to 3.438 MOA. The practical application ahs become one mil= 3.5 MOA. The Mil-Dot reticle is employed by placing the reticle over the target and aligning one end of the target to the flat of the reticle. The number of Mil-Dots are counted to provide an accurate reading.
MILLIRADIANS (MRAD)
A unit of measurement used to determine the divergence of a laser beam. The miliradian is equal to 0.001 radians and corresponds to an error of 1 meter at 1,000 meters.
MILLIWATTS (MW)
A milliwatt is equal to one thousandth of a watt. A watt is a derived unit of power in the International System of Units (SI) and measures the rate of energy conversion. One watt is equivalent to 1 joule of energy per second.
MOA (MINUTE OF ANGLE)
Commonly used in the shooting world as a point of reference, a Minute Of Angle is 1.047 inches at 100 yards. Normal shooter application uses the simplified 1” at 100 yards. For perspective, the difference between using the exact 1.047 and 1” is 0,47” at 1,000 yards. So, if a reticle has a 1 MOA dot, the dot would cover 1” at 100 yards. MOA is also relative to the click adjustments on scopes and iron sights. Scopes with 1/4MOA clicks would require 4 clicks to shift the bullet impact 1MOA (1”) at 100 yards. The same adjustment would move the bullet impact 1MOA at 200 yards, which is 2 inches. A simple way to calculate MOA at ranges less than 100 yards is to use the 100 yard adjustment and doubling the number of clicks for 50 yards and doubling again for 25 yards. For example, if a scope has ½ MOA click adjustments, it will require 2 clicks to move the bullet 1” at 100 yards, 4 clicks to move the impact 1” at 50 yards and 8 clicks to move it 1” at 25 yards.
NANOMETER (NM)
A unit of length in the metric system equal to one billionth of a meter. Nanometers are the most common unit used to describe the manufacturing technology used in the semiconductor industry and the most common unit to describe the wavelength of light.
NEAR-INFRARED
The shortest wavelengths of the infrared region, nominally 750 to 2,500 nanometers. Also see How Thermal Imaging and Infrared Technology Works.
NOISE (HIGH PITCHED SOUND)
The sound you can hear is the high voltage transformer unit in operation. Auto gated tubes will produce this high pitched noise. The sound can be softer or higher at times, depending on how much the auto gated needs to perform. It is normal and it may be possible to hear this sound from a distance 2-5 meters.
NSN (NATIONAL STOCK NUMBER)
13-digit code identifying all ‘standardized material items of supply’ as they have been recognized by the United States Department of Defense. National Stock Numbers have come to used in all NATO countries pursuant to the NATO Standardization Agreements (STANAGs).
PHOTOCATHODE
The input surface of an image intensifier tube that absorbs light energy (photons) and in turn releases electrical energy (electrons) in the form of an image. The type of material used is a distinguishing characteristic of the different generations.
PHOTOCATHODE SENSITIVITY
Photocathode sensitivity is a measure of how well the image intensifier tube converts light into an electronic signal so it can be amplified. The measuring units of photocathode sensitivity are micro-amps/lumen (µA/lm) or microamperes per lumen. This criterion specifies the number of electrons released by the Photocathode (PC). PC response is always measured in isolation with no amplification stage or ion barrier (film). Therefore, tube data sheets (which always carry this “raw” figure) do not reflect the fact that over 50% of those electrons are lost in the ion barrier. While for most latest 3rd generation image intensifiers the photo response is in the 1800 µA/lm (2000 µA/lm for the latest Omni VI Pinnacle tubes), the actual number is more like 900 µA/lm.
PICATINNY RAIL/ MOUNT
Named after the Picatinny Arsenal in New Jersey, where it was developed, the rail comprises a series of ridges with a T-shaped cross-section interspersed with flat “spacing slots”. Scopes et al. are mounted either by sliding them on from one end or the other; by means of a “rail-grabber” which is clamped to the rail with bolts, thumbscrews or levers; or onto the slots between the raised sections. Picatinny rail sections are the current standard attachment methods for weapon accessories among US and NATO forces.
RESOLUTION
The ability of an image intensifier or night vision system to distinguish between objects close together. Image intensifier resolution is measured in line pairs per millimeter (lp/mm) while system resolution is measured in cycles per miliradian. For any particular night vision system, the image intensifier resolution will remain constant while the system resolution can be affected by altering the objective or eyepiece optics by adding magnification or relay lenses. Often the resolution in the same night vision device is very different when measured at the centre of the image and at the periphery of the image. This is especially important for devices selected for photograph or video where the entire image resolution is important. Measured in line pairs per millimeter (lp/mm).
Resolution in a thermal device is measured in pixels. The higher the thermals resolution the better, clearer the image will be. Keep in mind, when using the digital zoom on a thermal device, each click up will cut the resolution in half. So for example, if the thermal has a 640 core resolution, if you zoom in on click, it will become a 320 resolution.
Also the Pixel Pitch or (Micron) count comes into play. The thermal sensor's pixel pitch is a measurement of the spacing between each pixel in the digital picture. The unit of measurement is a micrometer, sometimes known as a micron. The best thermal optics are now those with a thickness of 12 to 17 microns. The lower the micron the better.
RETICLE (RETICLE PATTERN)
An adjustable aiming point or pattern (i.e. crosshair) located within an optical weapon sight
SIGNAL-TO-NOISE RATIO (SNR)
A measure of the light signal reaching the eye divided by the perceived noise as seen by the eye. A tube’s SNR determines the low light resolution of the image tube; therefore, the higher the SNR, the better the ability of the tube to resolve objects with good contrast under low-light conditions. Because SNR is directly related to the photocathode’s sensitivity and also accounts for phosphor efficiency and MCP operating voltage, it is the best single indicator of an image intensifier’s performance
SCINTILLATION
Also known as electronic noise. A faint, random, sparkling effect throughout the image area. Scintillation is a normal characteristic of Microchannel plate image intensifiers and is more pronounced under low-light-level conditions
SCREEN
The image tube output that produces the viewable image. Phosphor (P) is used on the inside surface of the screen to produce the glow, thus producing the picture. Different phosphors are used in image intensifier tubes, depending on manufacturer and tube generation. P-20 phosphor is used in the systems offered in this catalogue.
STADIAMETRIC RANGEFINDER
Allows the user to calculate the approximate distance to an object if its size is known.
STEREOSCOPIC NIGHT VISION
When two views or photographs are taken through one device. One view/photograph represents the left eye, and the other the right eye. When the two photographs are viewed in a stereoscopic apparatus, they combine to create a single image with depth and relief. Sometimes this gives two perspectives. However, it is usually not an issue because the object of focus is far enough away for the perspectives to blend into one.
SYSTEM GAIN
Equal to tube gain minus losses induced by system components such as lenses, beam splitters and filters.
VARIABLE GAIN CONTROL
Allows the user to manually adjust the gain control ( basically like a dim control ) in varying light conditions. This feature sets the PVS-14 apart from other popular monoculars that do not offer this feature.
WEAVER MOUNTING SYSTEM
A US weapon mounting system used for attaching sighting devices to weapons. A Weaver Rail is a weapon-unique notched metal rail designed to receive a mating throw-lever or Weaver Squeezer attached to the sighting device
ZEROING
A method of boresighting an aiming device to a weapon and adjusting to compensate for projectile characteristics at known distances.
