Image intensifiers FAQ
What is the difference between Level 1, 2, 3, 4, 5, and 6?
All our devices comes with state of the art Gen 2+ White Phosphor, MX10160 format, high-performance image intensifier tubes.
Level 1 | Level 2 | Level 3 | Level 4 | Level 5 | Level 6 | |
Model # | NVT-4 | NVT-5 | NVT-4 AG | NVT-5 AG | NVT-6 AG | NVT-7 AG |
Phosphor Color | Green | White | White | White | White | White |
FOM | 1400+ | 1600+ | 1400+ | 1600+ | 1800+ | 2000+ |
SNR | 23+ | 25+ | 23+ | 25+ | 28+ | 30+ |
Resolution | 57+ | 64+ | 64+ | 64+ | 64+ | 68+ |
Luminance gain | 25,120+ | 28,260+ | 31,400+ | 31,400+ | 31,400+ | 31,400+ |
Autogating | N | N | Y | Y | Y | Y |
High Bandwidth Spectral Range? | N | N | N | N | 380nm to 1100nm | 380nm to 1100nm |
What level intensifier tube is best for me?
Level 1: Best used in or near urban areas, or in rural areas on clear nights with at least half moon.
Level 2: Best used in in or near urban areas, or in rural areas on clear nights with at least quarter moon.
Level 3: Best used in or near urban areas, or in rural areas on clear nights with at least quarter moon, and you are expecting intermittent sudden light exposure such as vehicle headlights, muzzle flashes, etc.
Level 4: Best used in urban or rural areas such as farms with clear skies, and you are expecting intermittent sudden light exposure such as vehicle headlights, muzzle flashes, etc.
Level 5: Best used in urban or rural areas such as farms with very low light, no moon and clear skies, and you are expecting intermittent sudden light exposure such as vehicle headlights, muzzle flashes, etc.
Level 6: Best used in urban or rural areas such as farms with extremely low light, no moon and cloud cover, or under forest canopy, and you are expecting intermittent sudden light exposure such as vehicle headlights, muzzle flashes, etc.
Are Gen 2's any good?
Gen 2 has come a long way, and high end Gen 2's are pretty close to even the most advanced Gen 3 devices. Here's a short video comparing different levels of Gen 2 with high end Gen 3 night vision.
Do Image intensifiers "wear out"
In short, yes.
The good news is that it takes an extremely long time.
When you look at the data sheet of your image intensifier, you will find a metric called "MTTF - mean time to failure". For most modern tubes, the number should be at least 10,000 hours.
What does that mean in real life? If you use your device for 6 hours, every single night, it will take approximately 5 years to reach 10,000 hours.
Most people will never use their night vision that much and that often. 4 hours a few times a week is pretty much the most a normal person will ever use their device.
At that rate, it will take you 14 years to wear out your tube - and that is still considered very high usage.
Having said that, improper use of your device can certainly speed up the degradation. Never turn on your device during the day without proper lens covers, never look at bright lights unnecessarily, etc.
What is autogating?
Autogating helps improve the performance of night vision devices by automatically adjusting the intensity of the incoming light to optimize image quality in dynamic lighting conditions.
Autogating systems continuously monitor the intensity of incoming light. When sudden changes in ambient light occur, such as from bright light sources or sudden flashes, the autogating system quickly adjusts the sensitivity of the image intensifier tube to prevent image blooming or saturation. Blooming occurs when the image intensifier tube becomes overloaded with light, causing bright areas to bleed into surrounding dark areas and reducing overall image clarity.
By dynamically controlling the amount of light allowed to pass through the image intensifier tube, autogating helps maintain a consistent level of image quality. It ensures that the night vision device can effectively adapt to changing lighting conditions without compromising image clarity or detail.
How important is autogating?
For normal use (most people), autogating is not essential. Image intensifiers without autogating have ABC (Automatic brightness control), which works similar to autogating, and will protect the tube against sudden changes, albeit not quite as effectively as autogating tubes.
If you are using night vision in an environment where you are expecting sudden flashes, moving between low light and high light areas, intermittent exposure to oncoming vehicles, etc, you might want to consider a device with autogating tubes.
What is illumination gain?
Illumination gain quantifies the degree to which the device amplifies the incoming ambient light from the moon, stars or distant cities. A higher illumination gain results in brighter and clearer images, allowing users to see better in low-light environments.
What is resolution?
This refers to the resolution of the image intensifier tube, which is the key component responsible for amplifying light in night vision devices. Image intensifier resolution is often measured in line pairs per millimeter (lp/mm), and it indicates the device's ability to distinguish fine details in low-light conditions.
The human eye can't distinguish any difference in detail in tubes 64lp/mm or higher. Tubes with higher resolution are usually only needed where magnification in necessary, for example in scopes or binoculars.
What is SNR (Signal to Noise Ratio)?
Signal-to-Noise Ratio (SNR) refers to a measure of the quality of the image produced by the image intensifier tube. It quantifies the ratio of the desired signal (the image of the scene being observed) to the background noise present in the image.
The signal is the light from the scene that is amplified and displayed to the user, while the noise consists of any unwanted electronic or ambient light interference that can degrade the image quality.
A higher SNR indicates that the signal (the image of the scene) is stronger relative to the noise, resulting in a clearer and more detailed image. Conversely, a lower SNR indicates that the noise is relatively stronger, which can result in a grainy or unclear image.
What is FOM (Figure of Merit)?
The Figure of Merit (FOM) is a metric used to quantify the performance of an image intensifier tube. The FOM is used to assess the overall quality and sensitivity of the image intensifier tube.
The FOM is typically calculated by multiplying SNR and Resolution
- stands for Signal-to-Noise Ratio, which represents the quality of the image produced by the image intensifier. A higher SNR indicates a clearer and more detailed image.
- stands for Equivalent Background Illumination, which represents the level of background light or noise present in the image. Lower EBI values indicate less background noise.
The Figure of Merit provides a measure of the overall image quality, with higher FOM values indicating superior performance of the night vision device.
Night vision devices with higher FOM values are generally more effective in low-light conditions and provide clearer and more detailed images with less background noise.
Will my night vision device have spots in the view?
This intricate production leads to unavoidable imperfections like dark spots and "pepper" (small, less noticeable spots). It's important for users to understand that these imperfections are common and don't affect the tube's performance.
Even the highest-quality tubes have these flaws within certain tolerances.
While it's natural to desire a flawless product, the reality is that all tubes, including top-tier ones, can have dark spots and pepper to varying degrees.
I like to think of them as birthmarks.
In practical use, these imperfections are often unnoticeable, much like the spots on a car's windshield that don't obstruct driving.
This is the chart that shows the allowable spot sizes and zones, where zone 1 is the center, zone 2 is in the periphery, and zone 3 is near the edge.
Spot diameter with contrast over 30% |
Zone 1 | Zone 2 | Zone 3 |
>300μm | 0 | 0 | 0 |
230~300μm | 0 | 1 | 1 |
150~230μm | 0 | 1 | 1 |
75~150μm | 1 | 3 | 3 |
Level 5 and 6: Maximum number of spots in cathode zones:
Spot diameter with contrast over 30% |
Zone 1 | Zone 2 | Zone 3 |
>300μm | 0 | 0 | 0 |
230~300μm | 0 | 0 | 0 |
150~230μm | 0 | 1 | 1 |
75~150μm | 0 | 2 | 2 |
Tube Phosphor colors:
The actual colors of white phosphor intensifier tubes may vary slightly from tube to tube. This is completely normal and occurs due to minor variations in the manufacturing process. These differences can result in slight shifts in hue, ranging from cooler blue tones to warmer white tones.
Additionally, it is important to understand that no white phosphor tube is truly "black and white." The image will always have a subtle tint, typically ranging from bluish-gray to warm white, depending on the specific tube. These variations do not affect the tube's performance, clarity, or durability and are within the acceptable quality standards for high-performance intensifier tubes.