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09 November 2021

Seeing the light: advances in optical illumination


Regular PPC contributor Dave Archer is back. And now he’s got optics in his sights. Dave reviews the technology that significantly changed his practice.

advances in optical illumination article for pest managment magazine PPC

Over the past few decades there have been huge technological advancements made in the pest control world.

Whatever facet of the industry you’re employed in, you cannot fail to have been impacted by the developments.

There’s digital images or alerts of sprung traps being sent to your mobile device, or real-time vehicle tracking and monitoring information.

For me, even in the field of rural wildlife management, the changes are apparent, especially in the recent developments of night-time illumination and rifle optics.

To be totally honest, I am no techie, as those who have seen my displays at events will readily agree.

But here’s the thing - I can walk in the woods or on an open field under a new moon without any need for artificial illumination.

I’ve trained my eyes over the years to be as efficient as they can be under the cover of darkness.

It now makes me smile that at the first phase of dusk (did you know dusk has three specific phases?) my comrades are using torches, mobile phones or whatever and basically making their presence fully apparent.

It is more like a rural Mariah Carey concert than a hunting foray.

Hindsight is a wonderful thing

In the 1970s, nighttime illumination was, at best, very primitive as far as pest control was concerned. The commercial market did not have any high-intensity night beams or high-powered LED torches.

If there was a need for night-time illumination more than a single torch bulb, it was necessary to construct something.

To assist me in seeing foxes on my nocturnal forays, I attached a motorcycle battery to an old car headlight to illuminate the fox’s eyes at night.

The battery was light enough to be kept in a wax jacket exterior pocket. However, the only wax jackets available in those days were expensive and had to last a good many years.

On one occasion, when moving around outside, the battery slipped in my pocket and battery acid leaked out.

This event went undetected especially as it was during the hours of darkness, until around three weeks later when I discovered the wax stitching had corroded due to the acid leak and the pocket fell off! An expensive mistake!

Tapestry of light

Tapestry of light

Before we look at modern optics, you may often wonder why certain animal’s eyes reflect so brightly at night; the so-called ‘cat’s eyes effect’.

The reason is thus – nocturnal mammals need to gain as much light as they can when moving or hunting in darkness.

The tapetum lucidum (tapestry of light) , the eye’s biological reflectors, give the eye a second opportunity for visual sensitivity to reflect light back, rather than be absorbed as is the case in diurnal mammals.

This reflected light is picked up by nightlights and is the animal’s unfortunate giveaway.

Having had over forty years of hunting experience, eyes tells me straight away what species of animal is in the lamp: foxes, deer, cats etc.

Not only does the colour give a good indicator, but also the way the eyes move in the darkness tell me a great deal regarding the animal the light is being directed toward.

Seeing the light

Nowadays all this has changed – there are now thermal imagers that show an animal through a lens in total darkness.

Added to this, night vision rifle scopes will give a clear image of the target.

A modern thermal imaging device used to detect heat sources wild animals

Look through any shooting magazine and it is full of these devices. (Later, I will elaborate on some reservations I have about these devices.)

Modern technological advances now mean one can hunt, say, a fox or rabbit in complete darkness and even shoot it with no assistance from torchlight.

However, be warned – shooting at night is one of the most dangerous forms of pest control! You don’t have the luxury of being able to ascertain distances and backgrounds as you can in daylight.

And, if you are looking to further this aspect of your work, I cannot impress more strongly that, in your first forays, you should be accompanied by a very experienced person.

However, be warned – shooting at night is one of the most dangerous forms of pest control! You don’t have the luxury of being able to ascertain distances and backgrounds as you can in daylight.

Read all you can on the subject and check on available training via shooting organisations.

Don’t go onto unfamiliar land or where you have no permission, even to shoot rats. It’s illegal!

Check areas in daylight, and know both yours and the topographical boundaries and limits.

My mantra for any pest control shooting activities: once you pull the trigger, you must be 100% sure of your actions because you can be 100% sure that the bullet will never ever go back into the gun.

For all the technology available, unless in very special circumstances, it’s illegal to shoot any deer, with any weapon, one hour after sunset or one hour before sunrise.

You will invariably see deer through thermal imagers etc but that does not give you the right to pull the trigger.


On a personal level, I’m still not convinced by the new technology.

I feel it gives the shooter an unfair advantage; do we start to lose respect for our quarry and lose all the skills of fieldcraft?

Yes, I am an old hand at this now but when people tell me night vision is a game-changer I think it confirms my thoughts.

I would much rather know my quarry by daytime and catch them with their ‘pants down’ at dusk or in sunlight on an open field.

I shoot more foxes in daylight now than I ever did at night in years gone by. At dusk, whistling foxes in is far safer than during the cover of darkness.

Additionally, one can purchase electronic fox callers to simulate an animal in distress, which makes the fox come running to see what’s happening.

A digital fox caller

The units have many types of digital distress calls built-in or, on higher-end models, the distress call can be downloaded to the device.

The calls range from distressed rabbits to crows.

These are useful in daytime forays as the sender unit can be set up away from a field hedge; the fox loses wariness when travelling to the middle of a field as opposed to coming toward you directly in a hedgerow.

Some modern units can emit the call from around 275m from the sender but I think this is too far.

I’d never attempt a rifle shot at that distance, 180m is my maximum.

Further than this, then the shooter may not be patient enough to wait until the animal is within their range of competency. Long distances risk wounding as opposed to a clean kill.

But as I stated earlier, I know I’m an anachronism but I really don’t mind. You may be totally at ease with the new technology or the article may have sparked an interest for you – and that can only be a good thing.

Agree or disagree with Dave? Tell him!

Send us your replies for Dave. Alternatively, you can write your own opinion piece for PPC. Contact PPC today.

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