Handheld spotters: night vision or thermal?

Patrick Hook highlights what to consider to make the right choice for your needs

One of the most common questions for those taking up night shooting is which type of spotter to use. In essence, there are two basic types – night vision or NV (either tubed or digital) and thermal. The former give an enhanced view of the landscape by massively amplifying the amount of light they receive. Thermal imagers, however, work on an entirely different principle – they ‘see’ the world in the infrared part of the spectrum (in other words, in varying degrees of heat) and then translate the information into a visual form.

One of the advantages of NV is that when it’s teamed up with a good infrared illuminator, you can often identify animals at enormous ranges. In the right conditions, for instance, the eye-shine from a fox can give a positive identification at 800 yards or more. NV has its drawbacks when used in the spotting mode, though – for a start, scanning a landscape properly takes a lot longer than when using a thermal. This is because the only way to quickly pick a living creature out of ‘busy’ scenery is if it looks at you and you get a flash of eyes. Otherwise you have to stare endlessly at any objects of interest in the hope that you get a glimpse of movement. With a thermal you don’t need to because if it’s living, it’ll be hotter than the objects around it and will stand out instantly.

The other situation in which thermal spotters win hands-down is when it’s misty, especially if there’s a bright moon.

Under those conditions every single droplet of moisture in the air will be lit up, making it next to impossible to see more than a few yards if you’re looking through any kind of NV device. Adding more infrared just makes matters worse, like putting your vehicle’s headlights on full beam while driving in thick fog.

Thermals are unaffected by this, although they can be compromised when everything is at more or less the same temperature, such as after a lot of rain. Years ago, thermal imagers were mostly big, clunky ex-military affairs that very few of us used. Since those heady days, however, they’ve become mainstream items and few serious shooters would contemplate going out without one; I certainly wouldn’t.

Considerations

Thermals are battery-hungry: a typical spotter will flatten one in around three hours, whereas I only change those in my tubed NV systems after four or five months.

One of my pet hates with most kinds of digital equipment is that there always seem to be so many buttons to press. When I only have a second or two to get on target and pull the trigger, I don’t need to be faffing about resetting this, that and the other. To me, it should be: device on, safety off, on target, bang.

“The other situation in which thermal spotters win hands-down is when it’s misty”

I also like my spotter to have the same brightness as whatever I’m shooting through so there’s a smooth optical transition from one to the other. You simply can’t respond quickly if you’re blinded by the glare from your riflescope the moment you turn it on.

When it comes to usable ranges, NV is the clear winner – but for me that misses the point, as the whole raison d’être is to use the spotter to tell you that a likely quarry candidate is ‘there’. You then use the NV on the rifle to confirm its identity before lining up for a shot. In this role, the thermal spotter excels as it is so much faster.

These days you can set your thermal up in so many different ways that covering all the different modes isn’t possible outside a book. These include such things as ‘picture-in-picture’ – whereby a small window shows a zoomed-in view of the central area, hot tracking, coloured palettes, range estimation, black hot/white hot and so on. What suits you and what doesn’t is naturally a very personal thing – I like my image to be as simple as possible so that my brain can immediately interpret what it sees without any unnecessary distractions. So, weigh up what you need and make your choice.

Many thermal systems have all manner of extra features built in – this image shows a ‘hot tracking’ facility, where the green cross denotes where the hottest component is – in this case, it’s a fox.

It’s important to remember that thermal imagers use software that auto-adjusts the final image to level off any particularly hot objects, such as these close-up cows. As a result, the background – which is much cooler – more or less disappears.

Interpreting what you’re seeing is not always easy when using a thermal. I spent ages trying to identify the hot object seen here (with a picture-in-picture setting) which was only about 100 yards from me. Eventually, it transpired that it was actually three rabbits sitting next to each other.

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Another feature that many thermal systems offer is the ability to have full or part-colour palettes – here, a view across a field and into a farmyard shows the hot spots on a flock of sheep in the foreground as well as those on a herd of cattle at the back.