Night Vision Devices for Surveillance

Let’s look at Night Vision Devices (NVD) for long range surveillance.

We’re going to review how night vision works, and how you can practically apply it for medium to long range surveillance.

We’ll be talking about Image Intensification (I2 or I2) technology.

How Night Vision Through Image Intensification Works

Let’s talk about Image Intensification.

This is a light intensification method.

In a nutshell, the electronics take the available ambient light (such as moonlight, starlight, etc.) and amplify it to a level that can be seen.

It’s important to note that there is not much ability to determine colors with night vision. Depth perception can be a problem as well.

What does this night vision view look like? Here’s an example.

View through a high quality night vision device.
View through a high quality night vision device.

The image is shades of green – a familiar look you’ve probably seen in the movies (or maybe in real life!)

Why is it green? Because green phosphorous is used as part of the light intensification electronics.

Let’s take a look at that.

Light (consisting of “photons”) comes into the device’s lenses.

The device contains one or more “Image Intensification Tubes” or IITs.

These contain a few things – the most important being a Micro Channel Plate and some form of green or white phosphor.

The light coming in can be starlight, moonlight, or other light sources like street lights, etc.

The available light is amplified into a viewable image.

A simplified view of how the electronics of night vision provide image intensification
A simplified view of how the electronics of night vision provide image intensification

There’s one more important caveat to this.

The best Night Vision Devices (NVD) that utilize nothing but ambient light are very expensive.

If you opt to use older (more affordable) technology you can save a lot of money – but you’ll have to understand IR illuminators as well.

An IR illuminator projects invisible (to the naked eye) near-Infra Red (IR) light.

But, this light can be picked up by the night vision device.

This is how game cameras and home security cameras with night vision work, by the way. They use a projected IR light.

Otherwise, they’d just be too expensive.

What’s the downside of this extra IR illumination?

Well, it’s generally pretty short range (a few meters at best) – and it is easily viewable by others with night vision devices as well.

That means when you are in the dark using an IR illuminator – you will stick out like a sore thumb to any one else with an NVD.

Having said all that, we’re discussing civilian surveillance here – so it’s reasonable to think that whomever you are surveilling doesn’t have night vision.

As such, most of the devices we’ll look at will include an IR illuminator – and you’ll need to use it to get satisfactory results.

And by the way, we’re not talking about Thermal Imaging here – that’s something different.

Thermal Imaging (“heat vision”) uses the radiated IR energy from objects and the background.

Tactical Night Vision Goggles vs Surveillance Night Vision Devices

Let’s talk about form factors next.

When you are researching Night Vision you are going to find a lot of information on NVGs – Night Vision Goggles.

These are meant for tactical use – combat, law enforcement, etc.

A quad tube Night Vision Goggle with a helmet mount - this is meant for tactical applications.
A quad tube Night Vision Goggle with a helmet mount – this is meant for tactical applications.

The quad tube “Panoramic Night Vision Goggle” shown above offers excellent field of view and detail and clarity.

It’s also super expensive.

For surveillance purposes – you really want a hand-held or tripod mounted device.

Goggles are great for hands free use – but they don’t offer any magnification (1x only).

This means they aren’t useful for surveillance.

Therefore, for civilian surveillance purposes (private investiators, etc.) we recommend a monocular (one tube) or binocular (two tube) device, that includes magnification. We’d recommend 3x – 5x magnification.

After all, we’re talking long range surveillance here.

What do these look like? Here’s an example.

Nightowl Optics - Gen 1 Night Vision Binoculars
Nightowl Optics – Gen 1 Night Vision Binoculars

These are Night Vision Binoculars from Nightowl optics.

As you’d expect – they look like a pair of binoculars.

Take special note of the protective lens caps – these are double important on a night vision device – which can be permanently damaged if subjected to full daylight.

These are a “Generation I” or Gen1 device.

What does this mean? It means they are huge – take a look.

Gen 1 Night Vision Binoculars - they are quite large.
Gen 1 Night Vision Binoculars – they are quite large.

In all seriousness, Generation I is the oldest night vision technology you can buy.

So it’s cheap(er).

But, it’s also heavier, bigger, and doesn’t have anywhere near the quality and clarity of the latest gear.

It doesn’t work as well with minimal light – so you’ll get best results with an IR illuminator.

But, if it works – it works. And Gen 1 night vision is better than no night vision.

Let’s talk a bit more about the different generations of technology in night vision devices.

But first, an important caveat.

Are Night Vision Devices Legal in the US?

There are no laws restricting the purchase, use, or possession of night vision devices by US citizens.

You are free to buy (and use) the latest technology all you want.

However, you cannot export, sell, or send the latest technology to other countries.

You also can’t let non-US citizens view or use night vision devices (or the manuals) – even if they are on US soil at the time.

This is serious business. It’s called the ITAR (International Traffic in Arms Regulations) and the EAR (Export Administration Regulations) regulations.

And if you violate them – you are looking at jail time.

Having said all that – we’ll assume you are a US citizen and you are buying and using these devices for your own personal use – there’s absolutely no problem with that.

But, there is one more important caveat. Many vendors will not sell the latest technology and devices to individuals.

They only sell to the US government or local law enforcement groups.

Why? Because there’s not an unlimited supply of these high-tech new devices – and often the vendor wants to ensure the US government gets priority.

Want to avoid all this hassle? Then steer clear of Gen3 or Gen3+ technology. Gen1 and Gen2 (Gen2+) are well known worldwide and not subject to these restrictions.

Night Vision Technology – Generations

There are three major generations of night vision technology, with some “half steps” between a few versions.

How do we judge one generation against another?

There’s a few objective qualities we can use: image quality (resolution), sensitivity, and maximum Signal to Noise (SNR) ratio.

We’ll start with Generation I technology.

Gen1 technology started with the Starlight scopes of the 1960s.

They will work best with active IR illumination – but they don’t strictly require it.

Resolutions are pretty low – which means the picture won’t be very clear.

Gen2 devices use newer technology. This includes multi-alkali photocathodes that are sensitive in the visible and near-IR bandwidths.

Gen2 also includes the MCP – Micro Channel Plate.

Image resolution, Signal to Noise Ratio, and sensitivity are greatly improved over Gen1.

There’s also an informal classification called Gen2+ – these use the same basic technology elements – but the latest versions.

For individual/consumer use Gen2+ is really, really good.

Resolutions can be in the mid-50 line pairs per millimeter (lp/mm) range.

Gen3/Gen III devices use galium arsenide (GaAs) photocathodes that are much more sensitive.

Gen3 is the latest and greatest advanced technology – and it’s covered by those ITAR and EAR regulations we talked about earlier.

Resolution is very good (64-75 lp/mm is not uncommon) and the IITs last longer too.

Need to take photos (night vision photography) or videos over night vision? Gen3 is your best bet.

But, it’s really expensive, and you might have a hard time purchasing – for all those reasons we discussed earlier.

In the end – it’s going to be a balancing act.

What do you truly need, and what is your budget?

With all that out of the way – let’s look at some night vision devices for surveillance.

Night Vision Devices for Surveillance – In Summary

For night time surveillance purposes, we recommend Gen2 or Gen2+ technology in a hand-held monocular or binocular setup.

This will offer a good compromise between flexibility, affordability and image quality.

We hope this has been helpful, if you have any feedback, please feel free to leave a comment.

References

International Traffic in Arms Regulations (“ITAR,” 22 CFR 120-130). These implement the Arms Export Control Act (AECA) – this is a long read, but interesting.

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