Sunday, May 5, 2019

Binoculars - The Big Picture

Binoculars – The straight goods – what to buy – how to adjust them

As trackers tend to move fast and light, the best binoculars are compact, light, and powerful. The rule of thumb is to buy the best quality that you can afford. What you are paying for is higher quality optics. This usually results in crisper focus and better low light performance.

What do the numbers mean?

Binoculars have a couple of numbers stamped or embossed on the housing. Expressed as two numbers such as 7X35 or 8X40, the first number is the magnification. So, a “7” means that the image produced is 7 times larger than what would be seen by the naked eye at that distance. Most people find that a magnification between 7X and 10X is suitable. Lower powers tend to have a larger field of view, so you see more area, whereas, higher magnifications generally have a smaller field of view. Higher magnification can also be harder to hold steady which could result in a “shaky” view. The second number indicates the size of the “objective” lenses in millimetres, (these are the bigger diameter lenses opposite the eyepieces). The larger these lenses are the more light that is gathered to form an image. Basically, the higher the second number, the brighter and the sharper the image. The down side is the larger the objective lenses, the bulkier the binoculars are and the more they cost.

How to adjust your binoculars for your vision.

To get the most out of your binoculars, lets take a couple of moments to find out how to properly adjust them for your vision thus insuring maximum performance.

Focus and adjustment

When you look at your binoculars you will notice that there are two optical tubes with a hinge in the center. On one end you will notice that the lenses are smaller than the other end. The smaller lenses are the “eyepiece” lenses that you look through. The first adjustment that you make is to bring the binoculars to your eyes and look at an object in the distance. What you see will probably be blurry and vignetted. Vignetted means that there will be a black area around what you see. To remove the vignette, move your eyes closer to the eye piece lenses and adjust the center hinge by gently spreading the optical tubes in or out until the vignette disappears.

The next step is to focus the lenses. Although some binoculars designed for heavy field use such as military applications have “independent” focus – meaning that each side can be adjusted to the user’s vision independently, most binoculars have “central” focusing.

Central focusing involves adjusting the focus of both optical tubes simultaneously by rotating the central knurled wheel - usually located in the hinge between the optical tubes. Simply roll the focus adjustment back and forth until a distant object comes into clear focus. However, as most of us have different vision in each eye, don’t be surprised if one optical tube will be in focus while the other isn’t... to check this, close one eye and adjust the focus, then close that eye and open the other and see if the focus is still clear and crisp. If it is not, you must set the binoculars up for your specific vision. To correct for this, one eyepiece is adjustable. The adjustable eyepiece is called a “diopter”.  You can tell the diopter lens as it has an adjustment ring on it with increment marks.

To adjust the diopter for your specific vision, focus the binocular on a distant object using the central focusing adjustment while keeping the eye looking through the adjustable diopter lens closed. Once clearly in focus, close the other eye and adjust the diopter lens until that eye is in focus. If done correctly, when you look through the binocular with both eyes open, your focus on a distant object will be crystal clear and crisp.

Once this adjustment has been made for your specific vision, the binoculars can be refocused on an object at a different distance by using the focusing wheel to adjust both tubes together without any further eyepiece readjustment. 

What not to buy
When shopping for a new set of binoculars it is best to avoid “focus free” or “fixed focus” binoculars or units with a zoom feature as these usually are a compromise at best. Other features like a built-in compass or a range finder are better suited for the marine or military environment that they were designed for.

The adage that “you get what you pay for” is especially correct when purchasing binoculars. For trackers, the best binoculars are compact, light, and powerful. Remember the rule of thumb is to buy the best quality that you can afford.  What you are paying for is higher quality optics. This usually results in a crisper focus and better low light performance. Consider your new binoculars a lifetime won’t be sorry going with quality.


Wednesday, May 23, 2018

Situational Awareness - Mind Veils

While walking up one of my favorite hiking routes, I heard some voices coming down the path. Stepping aside into a copse of spruce trees, but still in the open, I politely gave the hikers the right of way on the narrow trail.  Surprisingly, as the couple walked by in animated discussion, they passed right by me without seeing me. How is this possible I thought?

Analyzing the situation, there were several factors involved. The couple was actively engaged in a conversation making them less aware of their surroundings, and they seemed comfortable hiking in the area with no apparent safety concerns. Basically their “situational awareness” was close to non-existent.

For my part, although I was not wearing camouflage, I was dressed in muted earth tone colours and "I did not move" as they walked by. This wasn’t on purpose, in fact I fully expected them to see me and was prepared for the inane greetings of people who pass on the trail. At first blush, I thought that it was this unique combination of circumstances that made it possible to go unnoticed even though I was in plain sight and was in spitting distance of the closest hiker. Subsequent research showed that the real reason for my invisible act is even more surprising.

Although the above-mentioned details were all important factors that helped explain why the hikers did not see me; there was one crucial detail that I had overlooked…the fact that I was “standing inside the tree line.”

Cognitive psychologists who study human awareness have noted that the mind plays a funny trick when it perceives a physical barrier… the default condition is to not see anything beyond a wall. Remarkably, this “wall” doesn’t have to be a solid object but can be any representation of a barrier such as a tree line or even a chain-link fence. Under most circumstances we simply don't look beyond these mental barriers. While explaining this phenomenon in subsequent tracking classes, I coined the phrase “mind veils” to help students understand the cognitive process.  

Armed with this new information, I returned to the same familiar trail, but with one difference…I consciously looked past the veil of trees along the trail. Keep in mind that I have hiked this trail as often as once a week for over forty years so I wasn’t expecting any major revelations. To say that I was wrong would be a gross understatement. On one - 4 kilometer (2.5 miles) pass up the trail, I found items like an unbroken 1960’s glass root beer jug and a wrecked 1950’s car. I also spied a hunting stand, and a game trail camera. More disconcerting was seeing the remains of an abandoned marijuana grow operation that at one time was fairly sophisticated, complete with an underground irrigation system. This discovery begged the question, "how could a large marijuana grow operation be established, cultivated, harvested (for how many years?), and ultimately be abandoned (or shut down) without myself or some other hiker having noticed it? What else are we missing in our daily travels due to our inability to actually see beyond perceived barriers?  On this hike, armed with an understanding of “mind veils” and looking past the wall of the trees lining the path, all of this was easily seen – and in most cases, very close to the trail. What a shock.

The best part is that by recognizing mind veils, a whole new world has opened up. For instance, being a passenger on road trips allows me to observe beyond the trees, fences and other perceived visual barriers along the highway to see what is hidden – often in plain sight. Another example is in architecture. While dining at an industrial chic style restaurant I noticed that the designer overhead lights were suspended from some wood slats equally spaced above the tables. These wood slats are designed as mind veils to catch the eye so the open ceiling joists, exposed wiring, plumbing and HVAC – although easy to see if you are looking beyond the veil, doesn’t normally register with the conscious brain.

The interesting thing is that mind veils are not a new concept. The military has been on to this since the beginning of warfare. Think about snipers positioning themselves well back in a room or artillery placed inside the tree line fringe facing an open expanse. In-fact most ambushes wouldn’t work without the concealment offered by mind veils.

As a tracker, being aware of mind veils will substantially improve our effectiveness. Normally we are so focused on the ground in front of us we often miss clues in the surrounding area. Although the point tracker in a three-person team must be totally focused on the line of sign, the flanking trackers can easily scan their respective fields of observation beyond the veils.

  See you on the trail,



Monday, May 14, 2018

Search Dogs - The nose knows

Search and Rescue K9 

Guest blogger - Kelly Carnochan - Kelly is a "signcutter" level tracker as well as a certified SAR K9 handler. As the lead instructor, Kelly is also a major force at Northern

Most of us have seen search and rescue dogs locating lost children on television shows.  On TV, dogs use any means possible to find a lost person, from sniffing for human scent in the air to sniffing an article of clothing and tracking that individual's unique scent. We do not use scent discrimination (sniffing an article of clothing) to locate the missing person in Canada.

While search and rescue dogs are capable, in principle, of being trained as both air scent and trailing dogs, most dog handlers train their dogs to perform only one of these disciplines.  Therefore, the most valuable dog team, in terms of obtaining a high probability of detection, is one with a dog that can switch back and forth between air scenting and trailing as conditions dictate, I found with my K9 who was trained in air sent would automatically switch when she lost it in the air.
All humans, alive or dead, constantly emit microscopic particles bearing human scent.  Millions of these are airborne and are carried by the wind for considerable distances. They get caught up in the leaves of trees, will sit on the surface of water and many other areas.


Air scent dogs are the type most frequently encountered.  This dog finds the missing lost person by picking up traces of human scent that are drifting in the air, and looks for the "cone" of scent where it is most concentrated.  This dog will not normally discriminate scents, so there is the possibility of a "false alarm" if other people (searchers, citizens) are nearby.  Air scent dogs work best in situations such as large parks or private lands that are closed at the time, since the dog will hone in on any human scent.  The success of an air scent dog will be affected by a number of factors, including wind conditions, air temperature to hot or too cold, time of day, terrain, and presence or absence of contamination (auto exhaust, smoke, etc.).  The best conditions for air scent dogs to work are early mornings or late afternoons on cool, cloudy days when there is a light wind.


Trailing dog is often referred to as a "tracking" dog, although "tracking" and "trailing" are not the same to the purist.  The trailing dog is directed to find a specific person by following minute particles of human tissue or skin cells cast off by the person as he or she travels.  These heavier-than-air particles, which contain this person's scent, will normally be close to the ground or on nearby foliage, so the trailing dog will frequently have its "nose the ground," unlike the air scent dog.

A Bloodhound is typically trained for scent discrimination.  Each dog is usually worked in a harness, on a leash, and given an uncontaminated scent article (such as a piece of clothing) belonging to the missing person.  The dog follows that scent and no other.  At times, the dog may track, following the person's footsteps, or air scent, and home in on the subject's scent. 
Field contamination (scent of others) should not affect his work, because this dog has been given a scent article. He knows the scent he is looking for.  He should be able to trail scents on pavements, streets, grass, water, etc.  If there is a good scent article and a point where the person was last seen, a trailing dog can be the fastest way to find the victim.  Without the scent article and a point where the person was last seen, these dogs cannot work effectively.
While those are the two standard types of search and rescue dogs, there are also other dogs trained to find lost people.


Tracking dog is trained to follow the path of a certain person.  It physically tracks the path of the person, without relying on air scenting.  This dog is usually worked in a harness and on leash. This type of dog is effective when pursuing an escaped criminal if no scent article is available.  These dogs are also used successfully in search and rescue operations.


Disaster dog is trained to find human scent in very unnatural environments, including collapsed structures and areas effected by
tornadoes, earthquakes and other disasters.  This dog is trained to work on unstable surfaces, in small, confined spaces and other settings not usually found in the wilderness.

Cadaver dog reacts to the scent of a dead human.  The dog can be trained for above ground and buried cadaver searches.  Although many dogs have the potential to detect human scent, whether dead or alive, the cadaver dog is trained to locate only human remains.  The training process includes detection of very minute pieces of cadaver or even blood drops in a specified area. I am not sure if cadaver is recognized yet in BC.


Water search dog is trained to detect human scent that is in or under the water, focusing on the scent of the bodily gases that rise up.  As a team, the handler and dog usually work in a boat or along the shoreline.  Because of currents and general changes in the water, it can be hard to pinpoint the location of a body.  To enhance the chance of location, a diver should be ready to search as soon as the dog indicates.  Additional teams, unaware of the previous teams' findings, work independently to indicate a location.   This allows team members to determine the most likely location of the body.
An avalanche search dog is trained to detect human scent that is in or under snow, subsequent to an avalanche.  These dogs are trained to detect the scent under many feet of snow, sometimes, 15 feet or more! You can get more information at


For your best chance of survival, make it easy for the searchers and their canine partners to find you. If you get lost, STAY PUT.  Your chances of survival increase if you don't wander around.  You can aid the human searchers by placing easily seen colored items at eye height and in open areas which can be spotted from the air. Make an SOS out of rocks or branches for air support to see. Don’t be afraid of the canine he may look scary buy he/she will not harm you.

Searchers and family members must remember if you find anything belonging to the lost person do not touch them. If they are touched this will confuse the scent for the canine.

Establishing priorities if you are lost, especially if you are lost long-term, is one of the first steps to survival.  Basic needs are
food, fire, shelter and water Shelter is usually required first, but this can depend on where you are and individual circumstances.  An adult can survive for three weeks without food, but only three days without water.  Never wait until you run out of water before you look for more.  Conserve your supplies.   Remember that the human body loses 4-6 pints of water each day.  Loss of liquids through respiration and perspiration increases with work rate and temperature.  This must be replaced by actual water or water contained in food.  You can retain fluids and keep loss to a minimum by avoiding exertion, not smoking, keeping cool, staying in shade, not lying on hot ground, eating as little as possible, breathing through the nose and not drinking any alcohol.

Considering all of the above, always attempt to remain in the area in which you were first "lost" to make it easier for the rescue party and the specially trained canine to locate you.

*information taken from USSAR and Kelly Carnochan


Friday, April 27, 2018

Observation Skills

“With our limited senses and consciousness, we only glimpse a small portion of reality." 
Robert Greene

In the story “The Hounds of the Baskervilles,” Sherlock Holmes states that “The world is full of obvious things which nobody by any chance ever observes." Imagine being able to see what Sherlock Holmes sees. What would it be like to be hyper-observant? Seeing things that few others see. Experiencing events at such a dynamic level that every fiber of your being is engaged. 

There is no doubt that our everyday lives would be improved if we could enhance our observation skills. Most of us would be happy just being generally more aware, but imagine if you developed your observation skills to the level where you could appreciate art, music, and relationships at peak performance levels…so much more completely than you ever thought possible. Is this not the definition of being truly alive?

The question is, “how do we learn observation skills”?

First we must make the distinction between improved general awareness, often called “situational awareness” and specific awareness, referred to as being “hyper-observant” …which is what we are talking about here.

With training and practice we can certainly improve our situational awareness of the events that are happening around us. Being more aware is not really difficult when you consider that most of us are so self-absorbed that we go through our day in a complete mental fog, oblivious to almost everything happening around us. Observation skill training tends to help us cut through this fog… it’s like suddenly awakening from a semi-comatose state. We will explore “situational awareness” in future blogs.   

There is no doubt that improved situational awareness will have a huge impact on the quality of your life, but to really get the full experience from events we must become specifically aware - “hyper-observant”, and to do this we have to focus on a specific event. Psychologist call this having a “frame of reference.” In addition, you must purposely focus on the event with single minded intentionality. In other words, you must be aware that you are aware. Armed with a “frame of reference” and “intentionality”, there is one more ingredient required…you must know specifically what you are going to observe before the event.

To understand how the brain processes information from the five senses, we must realize that it is being constantly bombarded with thousands of sensory inputs every minute. However, as the brain can only process 30 to 40 items at one time, it tends to filter out the rest. Most of the allowed sensory inputs are unconsciously selected for basic self-preservation. Because of this, we simply can't observe everything all the time. However, with training we can alter the brain’s filters to recognize input from our senses other than just those required for basic functioning and safety; but, this requires conscious effort...we must task the brain to be on the lookout for something specific. In other words, we must actively tell our brains what we are looking for...the more accurate we describe this the better the chances that we will be able to observe it.

Using tracker training as an example… the core skill in tracking is the ability to see “disturbances.”  As a result, a lot of tracker training focuses on developing observation skills. In our “Basic Track Aware” course we introduce students to an exercise called “micro-framing.” While on their first line of sign, the instructor will place an 8 x 10-inch frame (think empty picture frame) over a track and have the students assume the prone position to closely study what is inside the frame. The instructor starts by pointing out the most obvious disturbances, then has the students (three students per line of sign) take turns pointing out three disturbances each – until everything that can be seen has been studied. The idea is to continue finding smaller anomalies up to the very edge of visual acuity…which is surprisingly small (micro). This exercise is repeated for two or three consecutive tracks and can take up to an hour.

On completion, the students are able to observe disturbances that they would not have been able to see prior to the “micro-framing” exercise. There is no magic here…everything within the 8 x10-inch frame became the focus, (frame of reference) and the task of finding every disturbance, (intentionality) created an environment that modified the brain’s sensory filters. Once in place, the student can “see” disturbances whether up close and framed or while tracking a line of sign. Like most things, this skill just gets better with practice.     

The exciting part about "hyper-observant" training is that once the skills have been acquired, the outcomes can be life changing. The interesting thing is that there is a distinct carry over from “seeing sign” while tracking to being more aware in everyday life. Keep in mind that the "micro framing" exercise is just one of many ways to improve observation skills. However, it is a relatively quick and easy way to demonstrate how hyper-observation skills can be developed and used. The bottom line is that depending on your aptitude and training, you can make substantial positive changes in your life by improving your observation skills.

Thursday, April 12, 2018

Tracking through the contamination

     “Sign” …the observable evidence of a person, animal or machine’s passage

For trackers, seeing “sign” is not usually the problem. Differentiating a disturbance made by the person that you are tracking from the contamination caused by something else is often the challenge.

In tracker training we spend so much time perfecting our observation skills that seeing even infinitesimal disturbances becomes almost commonplace. Where tracking gets difficult is in areas that are contaminated by disturbances caused by something or someone other than our quarry. On a pristine line of sign where the direction of travel and the stride length is known, any disturbance in the area where the next foot fall should probably what we are looking for. However, these “pristine” conditions are rare, and contamination is commonplace.  

At one event, the training area had been mowed a week before by an industrial machine that had chewed its way through the grass; followed by a dry spell making everything brown and crunchy. Adding to this mess, was a resident herd of elk trashing the ground. As a result, literally every square inch was disturbed...yet all the beginner trackers were able to follow a line of sign through the area. How did they do this?

The success of this challenging exercise could not be attributed to any one specific “thing,” but to the numerous techniques and skill sets learned and then practiced during the weekend course.  Let’s explore some of the basics here.

Originally developed by Ab Taylor and his team at the US border patrol, the “Step by Step” method of tracking is the foundation of training for many tracking schools in the Pacific Northwest (and elsewhere). At its most fundamental level, Taylor found that once the first few foot prints of the quarry being tracked are discovered, a simple measuring device made from a ski pole or broom handle could be marked with the measurement of the stride length, making subsequent foot falls easier to find.

The sign cutting stick causes you to look where you want to be looking, instead of everywhere else. The end of the stick becomes a pointer towards where the next sign or track is expected to be found.
“Fundamentals of Mantracking”
Albert “Ab” Taylor

Keep in mind that the disturbance found at the end of the stick rarely shows up as a distinct print but usually as an anomaly, or something that catches the eye as “out of the ordinary” or “out of place.” As well, by marking the approximate heel of each disturbance, (using a small piece of flagging tape), then visually lining up the marks, it only takes a few tracks to get an idea of the direction of travel.   

Once the tracker knows the direction of travel and the stride length, the probable area of the next footfall can be established, and the process of elimination begins.  By close observation, check to see if there is more than one disturbance in the proximity of the next footfall.  Ask yourself, "Can the source of any of the disturbances be identified as being made by anything other than the quarry, i.e. animal tracks, other people, etc.?"  The instructors at Universal Tracking Services (UTS) call this a “make it or break it” moment. By eliminating everything else – you are left with the most probable solution ...which is - “that you have found your next track.” For Sherlock Holmes fans, you will recognize this as his basic philosophy of crime solving.   

What this means to beginning trackers… is that during training, every footfall should be identified in the order that they appear. Identification ranges from observing almost microscopic disturbances to seeing near perfect signature prints. With unidentified anomalies, using a tracking stick to help measure the distance between footfalls and having a confirmed direction of travel helps differentiate disturbances caused by the person you are tracking from some other source. 

While tracking in contaminated areas, there are other techniques and skill sets that also come into play, such as the importance of “drawing prints” and “micro framing” to name a few...but these will be discussed in future posts.

See you on the trail,

Friday, April 6, 2018

Tracking in industrial security - terrorism, espionage, and theft

Resource based corporations, especially potentially contentious businesses such as oil and gas plants, pipelines and open pit mining, are at risk from home grown terrorism, corporate espionage and theft.

Training security teams in man tracking makes a tremendous difference in recognizing observable clues that could indicate potential threats. If tracking skills are applied consistently, many of the operations targeting industrial sites can be recognized and stopped in the beginning stages – often before serious damage or losses can occur.   

One technique is to create a “track trap” area paralleling the perimeter fencing that shows tracks and disturbances (sign). A track trap is simply an area of soft material that takes and holds a footprint. Traps are often naturally occurring with material like sand or soft dirt but may have to be worked up with hand tools or heavier equipment to be able to “take” a track. Regular perimeter checks, followed by brushing out the track traps as required, will enable security teams to be alerted to the presence of potential infiltrators. If foot traffic tracks are found, tracking teams can often “back-track” the line of sign to the insertion point – either a drop off site or staging area where vehicles are parked. Information such as “how many people were involved,” the time of the activity, and the number of vehicles involved, etc. can often be figured out. With this knowledge, a threat assessment can be made, and a plan of action developed...such as setting up surveillance, perimeter hardening, law enforcement involvement, etc.  

While working as a Loss Prevention Officer at an open pit coal mine in south eastern British Columbia, I discovered two uncontrolled entry points providing unauthorized access to the mine property.  With either route, anyone could gain access from a public paved highway to the mines’ service roads. Once inside the perimeter, trespassers could move about largely undetected. Especially if they had inside knowledge on where to go and how to act.

Once the unauthorized access points were identified, it was relatively easy to determine the types of vehicles gaining access to the mine property and the volume of traffic. On every shift I would count tire tracks and photograph the tread patterns in the soft dirt (track trap). By raking the area clean of tracks and disturbances each time, I was assured of fresh details every day. It was truly amazing the amount of unauthorized traffic using these routes. Based on the identified tread patterns, there appeared to be a few regular users and numerous random trespassers. As well, most of the tracks indicated light duty pick up style vehicles - not heavy transport types. This information helped us determine the activities of the infiltrators.

At another mine site in Canada’s Yukon Territory, prior to being trained as a tracker, I was involved in investigating substantial financial losses by what appeared to be systematic looting of mine property. Coincidentally, an observation post (OP) was found just outside the perimeter fence at a natural vantage point. It appeared that the OP was not connected to the theft ring but was part of a separate industrial espionage operation. The investigation team did not find the observation post; it was reported by a hunter with keen observation skills. However, if any of the investigators had tracking skills at the time, we may have been able to learn a lot more about the espionage group from the tracks and disturbances at the observation post. As a post script, this mine site was under siege from more than one group. Continued investigation also uncovered internal sabotage and agitated worker unrest. 

The bottom line is that tracker training provides industrial security personnel a huge advantage. Trackers are trained to establish a “base line” – a visual impression of what is normal, then observe and identify disturbances and anomalies (clues). Once the clues are identified, trained trackers can often follow the line of sign, providing the security teams with the information required to help prevent bad people from causing mayhem or loss to legitimate industry.

Tuesday, March 27, 2018

Night Tracking
The eyes have it – understanding how the human eye adapts for night vision

Canadian survival expert Mors Kochanski – the author of “Bushcraft”, really doesn’t like flashlights at all. This is even more remarkable when he discusses the merits of walking at night instead of the day on his famous 100-mile walk-abouts. Kochanski’s common-sense reasoning includes the energy saved by not having to have a fire at night to keep warm; then being able to sleep well during the heat of the day – without concern for nocturnal predators. Through a lifetime of experience without a flashlight in Northern Canada’s boreal forests, Mors knows a thing or two about night vision. Walking through the evening dusk into the darkest night, Mors simply lets nature do its magical adaptation, morphing daytime vision into the remarkable ability to see at night. 
Third generation tracker Fernando Moreira, started tracking when he was eight years old in his native Portugal. Decades later, living in Reno Nevada, Fernando is a dedicated (and respected) tracker recognized throughout the United states for his tracking skills. To acquire night vision, Fernando states that you must get the human body to produce and release the chemical associated with good night vision. To make this happen, he suggests that you sit in a dark room (or with a light proof shroud over your head) and using a red filtered light - look at the surrounding red shine being careful not to look directly at the light for about twenty minutes. Fernando suggests that you may have to repeat this exercise a few times to fully activate the chemicals in your eyes.

 In the book “Manhunter – a “must read” for trackers, Ian Maxwell goes into detail about “vision”. Maxwell describes the actual physiological functioning of the eye and explains how night vision works. Remarkably, the parts of the eye that allow us to clearly focus when there is a source of light, changes over to a support role in the darkness.  Basically, there is a small area at the back of the eyeball where lighted vision is concentrated on specific sensors called “cones.” These sensors allow us to detect colour, details, and distant objects. In darkness, the eye primarily uses different sensors called “rods.” Dispersed over a larger area, rods are located away from the central, cone rich area at the back of the eye. The result is that if you look directly at an object in darkness, the eye has difficulty seeing it… you must train yourself to use your peripheral vision to see things at night.  This is called viewing “off center”.

According to Maxwell, to gain “night vision”, there are four basic adaptations. When entering a dark area, the pupils enlarge allowing more of the available light to reach the sensors at the back of the eye; an area called the retina. Within about five to ten minutes of being in the dark, the cones become accustomed to the dim light and the eyes become a hundred times more sensitive to light. During the night vision adaptation process a chemical called rhodopsin is produced, which gives us night vision in about thirty minutes. During this adaptation process, the rods adjust to the darkness becoming 100,000 times more sensitive to light. Maxwell warns that fully adapted night vision can be lost with just a flash of white light. He recommends that to maintain night vision that strict light control is maintained. In one of our next posts we will explore what Ian Maxwell recommends for illuminating tracks at night.

The take home message from these three experts is that if we understand how our eyes adapt to low light conditions, we can continue to function at night...albeit at a diminished capacity. As night tracking is such an important topic, we will continue to explore more on night vision including what illumination to use. We may even be able to challenge some longstanding core beliefs about what lights are best.
See you on the trail,