Simple Explanation of Night Vision Models Differences

DISCLAIMER: The information provided in this article is a simplified explanation of the consumer qualities of the Night Vision devices sold by Basic Precision rather than a detailed technical paper. We omitted from our comparisons outdated Gen-1 devices and aviation-grade NV devices designed for an aircraft application. The data is provided for an average typical device of each generation of Night Vision.

THE SIMPLEST EXPLANATION:

Visual Comparison Of Night Vision Devices With Gen-2+, Gen-3+ and Photonis Image Intensifier Tubes (IIT)

A LITTLE MORE TECHNICAL DETAILS:

	Gen-2	Gen 2+	Photonis	Gen-3	Gen-3+
GAIN - the number of times a NV device amplifies light	10,000	25,000	30,000-50,000	40,000-70,000	60,000-80,000
Signal-to-Noise-Ratio (SNR) - influences the ability of an NV device to distinguish shades of darkness. The higher - the better!	up to 20	up to 25	up to 30	up to 35	up to 40
Resolution - the ability of a night vision device to distinguish the image details which are close to each other. It influences the image clarity. It is measured in lp/mm. The higher - the better!	45-54	52-64	64-78	64-72	64-82
Life Expectancy (a/k/a MTTF) in Hrs. of operation	10,000		12,000 to 15,000

A FEW MORE EXPLANATIONS:

Gen-2

Generation-2 night vision devices, unlike Gen-1 devices, can operate passively with no IR illuminator required. They intensify available light from the stars and moon 10 times more than Gen-1, making the scene visible to the human eye. An IR illuminator may be used when operating in complete darkness. They produce a cleaner and brighter image with no “fish-bowl” effect. Typical basic spec.: Gain-10,000x; SNR < 20; Resolution 45-54 lp/mm; life expectancy 10,000 Hrs.

Gen-2+

Newer technology used in Generation-2+ night vision devices allows for 2.5 times greater light amplification than Gen-2, along with improved resolution and a higher Signal-to-Noise Ratio (SNR). These enhancements ensure better image quality with less noise and a brighter picture. Typical basic spec.: Gain-25,000x; SNR < 25; Resolution 52-64 lp/mm; life expectancy 10,000 Hrs.

Photonis

Night vision devices built with Photonis tubes stand apart from the standard generation-based classification. Although some sources classify Photonis tubes as Gen-2+ devices, Photonis developed its technology differently, creating unfilmed light-intensifying tubes with exceptionally clear images and Automatic Brightness Control. In fact, every parameter of a typical Photonis tube exceeds that of a typical Gen-2+ device. Additionally, the resolution of Photonis tubes is equal to or higher than the typical resolution of Gen-3 and Gen-3+ devices. Typical basic spec.: Gain-up to 50,000x; SNR < 30; Resolution 64-78 lp/mm; life expectancy 12,000 – 14,000 Hrs.

MIL Spec grade Gen-3 Thin-Filmed

This technology is a significant step up from Gen-2+ and is often used by militaries. Gen-3 devices handle low-light conditions better than Gen-2+, providing cleaner and brighter images, being better in every aspect, including increased tube life expectancy. Typical basic spec.: Gain- up to 70,000x; SNR < 35; Resolution 64-72 lp/mm; life expectancy up to15,000 Hrs.

MIL Spec grade Gen-3+ Unfilmed

This is the most advanced night vision technology developed to date and is often used by special ops. Gen-3+ Unfilmed devices provide the cleanest, brightest images with the highest resolution. They also handle low-light conditions better than any other generation of night vision. These devices offer the longest detection and recognition ranges and are the most reliable and very durable. Typical basic spec.: Gain- up to 80,000x; SNR < 40; Resolution 64-82 lp/mm; life expectancy 12,000 – 14,000 Hrs.

OPTIONAL FEATURES:

Auto-Gating

This is often the most misunderstood optional feature of NV devices. A common myth suggests that Autogating can protect NV devices from bright light, including daylight. This is not true. Autogating serves a different purpose—it is designed to automatically limit the glow from light sources.

Autogated devices are essential for operating in environments with occasional or regular light pollution, such as military combat, law enforcement operations in urban areas, or hunting near a lit road or property. An NV device without Autogating will not allow the user to see what is happening behind a streetlight, as the amplified glow from the light will be too bright for the human eye to distinguish a darker background. An Autogated device is a game changer. Most Photonis, Gen-3, and Gen-3+ tubes are Autogated.

With all that been said, NV devices without Autogating are well-suited for use in areas with no light pollution, such as hunting in remote locations. In fact, if a hunting scene lacks any source of light pollution, a device without Autogating may slightly outperform a comparable device with Autogating. An Autogated device may attempt to soften the glow from the brightest element in the scene—such as a reflection from a game's eyes—whereas a non-Autogated device would render this reflection more distinctly.

Manual Gain Control aka External Gain Control (EGAC)

This feature allows operators to manually adjust the light amplification of a night vision device. Turning the gain down from the maximum level, will dim the image to the operator’s comfort level in a bright condition like a full moon or snow.

Automatic Brightness Control (ABC)

This feature automatically reduces the image intensifier’s brightness under dynamic lighting conditions. It may extend the tube’s lifespan by limiting the amplification of bright light peaks within reasonable limits. Automatic Brightness Control also protects the user from temporary blindness caused by an excessively bright image produced by a night vision device when unexpected light pollution occurs in the operating scene. The image brightens for a split second and then dims to a pre-set comfortable level.

Good Example of How All Three Features Can Work in One Device

The three features above are often confused with one another. The following example clarifies the difference:

If a night vision device has all three features—Autogating, Automatic Brightness Control, and Manual Gain Control—an operator can adjust image brightness to a personally comfortable level using Manual Gain Control. Autogating will automatically reduce the glow of any lit object in the hunting scene, such as a feeder light, allowing the operator to better distinguish objects in the immediate proximity to the light. If your hunting buddy thoughtlessly points a flashlight at your face, Automatic Brightness Control will quickly reduce the brightness to the level you previously set with Manual Gain Control. These features are even more valuable in night combat situations or urban law enforcement operations.

Please do not hesitate to contact us with any additional questions you may have.