Health Issues – Part V

Aug 6, 2013 | Safari Planning

 

I also think quite carefully about the unthinkable. In other words, what will happen if I fall ill or am hurt while on the hunt. Where are the nearest hospitals, what facilities do they offer, what is the standard of nursing and health care and, most importantly, how am I going to get to the nearest acceptable facility? One of my friends reduces this question to a very simple answer, namely, if it is in the northern hemisphere, fly to Zurich and, if it is in the southern hemisphere, fly to Cape Town. Has my professional hunter received any first aid training and has he had any experience in dealing with sick or wounded people, including snake, scorpion and spider bites? Do I have insurance which covers medical evacuation? Am I going to take my own medical kit and, if so, what should it contain? Fortunately, in this regard, my wife is a trained nursing sister and when it has been necessary to take my own medical aid kit, she has prepared a very comprehensive one.

 

Long before embarking on the trip I take time to consult an expert and, I stress, an expert, not merely a family general practitioner, as to medical precautions that can and should be taken before, during and after the trip. And I am not talking merely about things like the obvious malarial prophylactics. At various times I have been inoculated for smallpox, yellow fever, cholera, tetanus, polio, encephalitis, meningitis, hepatitis A, hepatitis B, rabies and flu. In some cases a series of injections is required. In the case of hepatitis B, for example, the course is spread over a period of three months, hence it is no good popping along to see your family GP on the day before you are due to leave. I always have a gamma globulin injection in the week before I leave as this boosts the body’s immune system in general, although it only lasts for a relatively short period of time, roughly about six months. In South Africa, I have found the Netcare Travel Clinic to be the most well informed, up to date and efficient operation for this kind of advice and service. Apart from anything else, their trained nursing sisters give so many injections every day that they are experts in providing the maximum amount of cover with the minimum amount of pain. They also keep your records on computer and can tell, instantly, which of your cover has expired, what needs boosting and what you need for every African destination.

 

Africa is a tough continent. It often seems that everything on it and in it, animal, vegetable or mineral, wants a piece of you. From the grasses that cut your arms and legs, to the thorns (of all sizes, shapes and descriptions) that are patiently waiting to take a piece out of you. And, of course, not to forget the snakes, scorpions, spiders, bees, wasps, mosquitoes, flies, fleas and ticks. Sometimes these space invaders come in more subtle forms, like the jiggers which lay in wait in the sand for the unwary who walk bare foot on the tempting, neatly swept, camp surrounds. An itchy bump on the bottom of your foot, with a little black dot in the centre, or, worse still, under a toe nail, will be the bad news bear. The black dot is actually a worm and must be removed carefully if infection is to be avoided. And then there are the flies that lay eggs on the inside of your clothing as it dries on the washing line. A good hot iron takes care of them so I am careful not to dress in un-ironed clothes.

 

This is a topic all of its own and a very important one. If you are allergic to any of these bugs it can make your safari a misery. If you are prepared, however, the marvels of modern science and a degree of caution and common sense can allow you to escape most of the unfortunate ‘accidents’ which befall the ‘un’ people – you know them – the unprepared, uneducated, unwilling to learn people. Because, although there are a slew of ointments, creams, sprays and pills to alleviate the symptoms, it is much better to take with you those things that will prevent you from being bitten in the first place. A careful questioning of the usual suspects will provide you with the relevant information. For example, if you spray your clothes with Bayticol it will keep the ticks off. If you pretend you are a colouring in book and Tabard is a crayon, that should keep the mozzies away and, I must confess, it has been ages since I have hunted in anything other than longs and long-sleeved shirts, no matter how hot it is.

 

At the end of the day, I know myself best and, for all those minor ailments that I can and do pick up in a strange environment, eating and drinking different food, under physically demanding circumstances, I usually end up being my own doctor. I make a list of things, starting at my head and ending at my feet, that I suffer from and take along those peculiar remedies. You know the ones – like Caltex CX3, they work for me!

 

Despite having walked hundreds of kilometres on safari, I have never had trouble with my feet. Not until hunting in Central Africa that is. One day tracking giant eland we walked 42 kilometres (calculated from way point to way point on the GPS). The tracks led us across the innumerable petite marigeaux (little streams) in the region and my well-worn boots retained the water wonderfully well. My well soaked, water softened feet developed the mother of all blisters. I had brought nothing for my feet. Fortunately, my PH knew exactly what to do. He extracted some of the fluid from my blisters using a syringe and replaced it with mercurochrome. If your eyes are starting to water as you read this then you are either an ex-paratrooper or have done this before. Yes, it burns like the fires of hell but, if you coat the blisters with antibiotic cream and wrap your feet in thick, white adhesive plaster, you can walk the next day and the next and…

 

Ever since, I pack a spare pair of boots and socks in the baggage man’s pack and, when my feet become soaked, change my footwear. Especially when hunting those animals you kill with your feet, like elephant and eland, bad or blistered feet can kill your hunt.

 

Conventions & Communications – Part IV

Aug 6, 2013 | Safari Planning

 

Obviously, the more important the hunt is to me, the more trouble I take to ensure that I book the right area, at the right time of year, with the best possible outfitter and professional hunter. Each year, there are a number of hunting conventions in North America and Europe at which all the top safari outfitters and professional hunters are represented. It is well worth attending one or more of these conventions. For example, the biggest convention of its kind in North America is the one held by Dallas Safari Club in January of each year in Dallas, Texas and, in South Africa, it is Huntex held in April half way between Johannesburg and Pretoria. These conventions allow you to do a large amount of comparative shopping and reference checking in a short period of time. Apart from anything else, these conventions are run by hunters for hunters and offer you everything that you can possibly think of which relates, directly or indirectly, to hunting, under one roof.

 

Having decided on where I am going, what I am going to hunt, what time of the year and with whom, there are a whole slew of other questions to which I need answers and it is a good idea to develop a second checklist of questions to ask the booking agent, outfitter, professional hunter and one or two chosen referees. Incidentally, when asking questions it is not a bad idea to send them off in writing and ask for written replies. The more of the correspondence that is in writing the better, particularly the correspondence with booking agents, safari outfitters and professional hunters and, in this regard, I always take a folder along on my hunt with the correspondence in it. This can really help to eliminate misunderstandings, particularly, if there are different home languages involved. This was really brought home to me at a French restaurant in Bangui in the Central African Republic. I ordered roast chicken in what I thought was impeccable and grammatical French. Fifteen minutes later, when the owner and his waiter had stopped laughing long enough to dry their tears, I found that I had ordered a roasted prostitute.

 

The one and only time I failed to correspond directly with the outfitter cost me a lot of time, money, pain and suffering. I had booked a 28 day hunt in Tanzania. In my written correspondence with the young professional hunter, who had quite literally begged for the opportunity, I specified that the object of the hunt was to try for a good quality lesser kudu. Hence I wanted to hunt for two weeks in Masailand, one week to explore along the Rungwa River in the south-west, and then back to Masailand for a week, where my wife was to join me before we travelled to the Ngorongoro Crater for a few days of game viewing.

 

Well, he never forwarded one bit of the correspondence to the outfitter. Not knowing my requirements, the outfitter assumed mine were the normal Tanzanian priorities of lion, leopard and buffalo and shipped me off to the Rungwa River. He had allowed me three days, in total, in Masailand.

 

Eventually, as I managed to sift through the fog of fabrications spewed forth by the duplicitous young man, I spoke directly to the outfitter. He was not to blame as I had been led to believe. In fact, he could not have been fairer or more obliging when he discovered my predicament. He allowed me a further two days, free of charge, in Masailand. Unfortunately, the five days were insufficient to obtain a lesser kudu and I had to book a second safari, which I did with the same outfitter, two years later. This time I shot a good representative lesser kudu in Masailand on the 12th day of the hunt.

 

So, at last, it’s off to the races. The questions that I now want answered relate, essentially, to clothing, equipment and medical matters, for example:

  1. What kind of hats are best?
  2. What colour clothing is best?
  3. Is camouflage allowed, if so, what type works best?
  4. Should I bring shorts and short sleeves or longs and long sleeves and, in what quantities?
  5. Is washing done daily?
  6. What kind of footwear is recommended and how many pairs should I bring?
  7. What about gloves, scarves, jerseys and jackets?
  8. What will I be sleeping on and in?

 

As regards equipment, it is not sufficient to ask advice merely with regard to calibres and cartridges. For example, when hunting in the Central African rain forests, it may be a good idea to take a pair of stout, garden secateurs to help cut entangling creepers. Duck tape may be needed to wrap around metal gun sights to prevent them snagging on the undergrowth. Boots with protruding metal eyes or catches for bootlaces must be avoided as they catch on the undergrowth and can cause the unwary to stumble and trip. On the open plains, a bipod or monopod may work best as a rest and, if hunting in the savannah, before the grasses are burnt, a pair of clear glass spectacles to shield eyes from the head high grasses which constantly flick in the face may be an idea.

 

What kind of luggage to take – hard or soft? Many hunters travel with soft duffel bags of various sizes because they pack easier in small aircraft. I never do. I always take a good quality, hard shell, lockable suitcase. The one I use is dust proof and waterproof. It provides much better protection for my clothing and equipment and, being lockable, is much more secure and not only from two-legged thieves. I always take glucose sweets for energy, much loved by mice and rats, who think nothing about gnawing through duffel bag canvass. If absolutely necessary, I pack a fold up, material duffel bag in my suitcase. I also always take a thin, waterproof gun sleeve. This takes up very little space and is useful protection for firearms, particularly when travelling in open hunting vehicles in dusty or wet conditions.

 

I try to establish the number of people that are going to be in my hunting team. For example, on some hunts the team may be quite large and consist of two trackers, a professional hunter, game scout, baggage man, driver and myself. The role of the baggage man is to carry food, water, first aid kit, GPS, cameras, spare footwear, socks and rain gear. On the other hand, it may be only myself and the professional hunter. In the former case, I may be able to take a video camera and a 35mm stills camera. In the latter event, I may be hard pressed to carry a pocket sized, ‘point and push’ camera in a moon bag on my back. In the case of cameras, video cameras and torches, I establish whether there is a facility to recharge batteries in the camp or from the vehicles that I use and, if so, what type of connections are required. And my equipment check list includes spare batteries for my stills camera, flash and distance measuring binoculars. For one reason or another, it seems easy to forget these tiny, little blighters.

 

Important Questions – Part III

Aug 6, 2013 | Safari Planning

 

I do not want to imply, in any shape or form, that everyone in the hunting industry is a crook but it does seem, at times, that every crook is in the hunting business. As such, before parting with any of my hard earned funds, the most important single thing I do is to check and re-check all the information I have been given and all the representations that have been made. In the early days, I used to hunt regularly with a group of close friends until one emigrated to Australia, the other to the U.K., one returned to Texas and the last one became a full-time professional hunter. We always used to do our homework thoroughly and booked our hunts a long time in advance in order to ensure that we secured the right place, at the right time of year, as well as the services of the people with whom we wanted to hunt. Most importantly, however, each year the role of checking out our proposed hunting area fell on the shoulders of one of the group. We did not part with a deposit until one of us had physically inspected the land on which we were to hunt and verified the facilities that were on offer.

 

Of course, the further afield I hunt, the more difficult it is to do this. As I have wandered into ever more remote areas, looking for ever more difficult species to hunt, I have reached a stage where there is no alternative but to rely on the representations of the booking agent, the outfitter, the professional hunter and the sportsmen who have hunted in the area before.

 

It was for this reason that, some years ago, I tried to develop a more objective data base. After six years, three failed attempts and many tens of thousands of Rands, I managed to computerize the SCI Record Book of Trophy Animals on an interactive basis. This software program allows me to ascertain, at the click of a mouse, which country, location in a country, professional hunter and amateur sportsman has the best record for any given animal in the record book. I can plot, on the map of Africa, which I can also enlarge, every species in the Record Book for which there is a designated location. By limiting my search by different time periods, I can also track whether trophy standards have improved or deteriorated over the period in a given location. The program is as good an initial research tool as it is in verifying representations made, as it is in providing the names of outfitters, professional hunters and amateur sportsmen to contact.

 

Fight fair I can hear you saying: ‘That’s an information system not available to anyone other than you.’ At the moment that is the case but this record book and the even older and more respected, Rowland Ward’s Records of Big Game, allow you to do the same thing albeit not so easily.

 

At the end of the day, however, I need to talk to people. In this regard I have drawn up a checklist of questions to some or all of which I need answers. I ask the same questions of each of the booking agents, outfitters, professional hunters and sportsmen I talk to and, if the answers to the same questions are different, a little amber light starts flickering in my head.

 

Some of the questions you may wish to ask are the following, namely:

  1. Can you give me the names, email addresses, telephone and fax numbers of people who have hunted the area that I am thinking about going to, for the species I am interested in, over the last three years?
  2. How big is the area that I can hunt?
  3. What other species can I take in the same area?
  4. What is your success rate over the last three years on the species that are found in the hunting area and can you give me measurements of these species taken over the last three years, by year?
  5. What is the best time of the year to hunt?
  6. What is the climate like at this time, including high and low temperatures?
  7. Who will my professional hunter be?
  8. How many times has he hunted the area I will be hunting?
  9. How many animals of the kind I will be hunting have his clients taken over the last three years and what are their measurements? Can you give me a list of their names, email addresses, telephone and fax numbers?
  10. Can you send me a photograph of the camp and two or three representative photographs of the terrain and bush in the area I am to hunt?
  11. If there is no permanent camp, please describe the camp that you will establish and the terrain in which it will be situated.
  12. Will we hunt exclusively from the main base camp or will we move to one or more other permanent or semi-permanent camps during the safari and, if so, why and for how long?
  13. Will we hunt exclusively from the main base camp or will we fly camp and, if so, why and for how long?
  14. Can you send me photographs of a typical fly camp and the other permanent or semi-permanent camps.
  15. Will I be sharing the camp with other hunters or have it to myself?
  16. What food and drink is served in camp and, when we stay out for the day, what food and drink is taken along and how is it carried?
  17. If I have any special preferences regarding food and drink will you cater for them or must I and, if you cater, will this affect the daily rate?
  18. Is there a current first aid and snakebite kit in camp, if so, what do they contain and is one carried in the hunting vehicle?
  19. What is the standard of the tracking staff?
  20. How many staff will there be in camp and what are their functions?
  21. What vehicle will we use to hunt and how old is it?
  22. Apart from the daily rate and the trophy fees, what other charges will there be attributable, directly or indirectly, to the hunt such as import or export charges for firearms or ammunition, government conservation fees, taxes and levies, trophy preparation, dipping and packing fees, documentation fees, airport departure taxes and so forth.
  23. What hunting methods do you use, walk and stalk, sitting at water holes, Toyota tracking, dogs, driven shoots and so forth?
  24. Is there poaching in the area that I will hunt?
  25. Are local citizens allowed to hunt in the area that I will be hunting, with or without licenses?
  26. Will somebody be there to meet me at the airport, if so, who?
  27. How do I get from the point of entry into the country to the hunting area and back, how long does this take and what does it cost?
  28. What other travel options are there, how long do they take and what do they cost?
  29. Which taxidermist do you predominantly send your trophies to?
  30. How fit do I have to be in order to enjoy the hunt?
  31. Where can I obtain a good map which includes the hunting area?
  32. If I am compelled to cancel my hunt after I have paid my deposit, what are the cancellation terms?

 

Seek References – Part II

Aug 6, 2013 | Safari Planning

 

I have a fairly good collection of African hunting books and I go through my catalogue to refresh my memory as to which books might contain detailed information on the animals and those people that have hunted them successfully. The series of books put out by Safari Press and edited by Tony Sanchez-Ariño entitled, Hunting in (African Country Name) such as Hunting in Tanzania, are also a useful source of information. However, to date, I have found The Hunting Report, to which I subscribe, to be the most fruitful source of up to the minute, written information. Staff, as well as subscribers, file reports by species and by country and, for a small fee, they will email copies of these reports to you. Apart from the useful information contained in the reports, they also provide a list of sportsmen who can be used as references and a list of safari outfitters for the particular animal(s) I am looking for and, if you are a regular subscriber like me, then you will also follow the controversies which they publish, usually between hunters and outfitters which can serve as warning of what and who to avoid.

 

In recent years, James Mellon’s magnum opus, African Hunter, has been updated and African Hunter II, edited by Flack and Boddington provides the most comprehensive overview of hunting in Africa that it is possible to obtain in one book. Subsequently, Safari Guide II edited by Flack and Neufeld was published – both books are available from Safari Press and Rowland Ward – and the latter one provides the most detailed information on hunting in all the various countries in Sub- Saharan Africa which offer the sport. If you are only going to consult two books, I can honestly say that these should be they.

 

Being an African, I subscribe to African Hunting Gazette, Magnum, African Outfitter and S.A. Game & Hunt magazines. But beware of those journalists who accept free trips and then write glowing reports about those they visited. As a regular contributor to all of these magazines, I believe they are the best hunting publications in Africa and are choc-a-block full of relevant information. They certainly help both fill my data bank and point me in the direction of people who may be able to help me.

 

Most booking agents, outfitters and PHs have websites and, for the sake of completeness, I mention them and, although I will look at them, I usually take them with a pinch, and sometimes, a bucket of salt.

 

Another good source of information, which I never neglect, is my taxidermist. Good taxidermists receive trophies from all over Africa and are in regular touch with safari outfitters, professional hunters and clients. There are 10 commercial taxidermists in South Africa and I have yet to find one who has not been unfailingly helpful. If, however, a taxidermist doubles as a booking agent, then the comments I make later regarding these gentlemen need to be born in mind.

 

Belonging to one or more hunting associations is, in my opinion, essential. I belong to three domestic associations, namely, Cape Hunt, the KwaZulu-Natal Hunting and Game Conservation Association and the East Cape Game Management Association. Again, I find members of these associations tremendously helpful, even insofar as international hunting is concerned, although, in this respect, you can do no better than to belong to Dallas Safari Club and SCI whose members are good sources of objective and unbiased information.

 

From these various sources I have now obtained a list of booking agents, safari outfitters, professional hunters and sportsmen to contact. The list of sportsmen is probably the most important as they should be able to provide the most objective and unbiased information and advice. As a general rule, I do not use booking agents, quite simply, because they are not objective. While they cannot recommend an out and out buffoon, as this would damage their reputation, I never forget that they earn their livelihood from commissions paid by outfitters and hunters. Some of the best of these, however, have such good reputations and are so well known that they do not use booking agents. You do not have to be a neurosurgeon to work out which outfitters and pros are going to receive the nod from the agents.

 

I should, however, issue a small word of warning here. The relationship formed between a client and a professional hunter is often a very special one. Over a three week safari you probably spend more quality time with your professional hunter than you do with your best friend over the course of a year. This relationship often grows into friendship and the client returns, year after year, to hunt with the same PH.

 

Asking such a client to give his opinion of that professional hunter is like asking a proud mother to give you an opinion of her prodigal son. Just as important when checking references, is to remember to ask how many times the referee has hunted in Africa as, it never ceases to amaze me, how often in following up a glowing reference, it is only to find that the referee is talking about his very first trip. In all honesty, such a person has no standard of comparison to go by and his reference is, to all intents and purposes, of very little value.

 

The Safari Decision – Part I

Aug 6, 2013 | Safari Planning

 

Everyone probably has their own way of planning a safari. On the one hand, there are those that book a safari the same way they would a restaurant. They have heard a rumour that a particular restaurant serves good food and so they book without knowing anything else other than its contact details. They have some good meals and some bad ones.

 

Then there are some people who almost invariably eat at McDonalds. There is at least one in every town. The meals are inexpensive, the service is quick and you know what you are going to get. There are still others who know, well before hand, exactly what they would like to eat and, in fact, can probably tell you which wine they propose drinking with which course and why. They book well in advance and would rather eat one good meal a quarter than take potluck once a week. These are people who are often passionate about food, discuss it with their friends, read about it and, probably, cook themselves. Although they do not necessarily live to eat, eating for them is more than just about satisfying hunger pangs.

 

As James Mellon wrote nearly 30 years ago in African Hunter, the bible on hunting on this continent, ‘Oh what traps and snares there are in the wilderness of possible safari arrangements!’ Today, his comments are even more relevant as hunting has become a very expensive pastime. And the more sought after the trophy, the more expensive it becomes. At the end of the day, only an extremely wealthy person, with masses of time on his hands, can afford to book a safari without careful research. In fact, there are only three things you need to know about booking a safari – research, research and research.

 

My research begins with a decision to hunt one or more particular animals. Like many of the stories that I write, this begins with a vague idea which, every now and then, pops out of my sub-conscience. When this starts to happen with greater frequency, I start to pay attention and actively begin thinking about hunting those particular animals. I normally start my research with the animals themselves. I glean what I can from the record books, namely, Rowland Ward’s Records of Big Game and SCI’s Record Book of Trophy Animals.

 

From there I turn to The Mammals of the Southern African Subregion by Skinner or some such other reference book and, of course, the internet and Wikipedia are also good if somewhat generalized starting points. Then, if I am still interested, I will dig further. By now, I have a reasonable idea of the animal, its habitat and, in which countries it can be found, and then I really get to work.

 

I confess, it is easy for me to become passionate about a given animal for a whole host of reasons. However, I try not to forget about the other animals that might occupy the same habitat as the one(s) I am particularly looking for or that I may find in the same vicinity. For example, you may be mad keen about hunting lesser kudu in Tanzania’s Masailand but there are also good fringe-eared oryx, gerenuk, Coke’s hartebeest and Patterson’s eland on offer. It would be silly to neglect these animals and, sometime later, have to book a second safari to the same area to complete a collection of oryx or eland, for example.

 

HAWASA – A Unified Body Of Hunting And Wildlife Associations

Aug 5, 2013 | News

Comments about dissension among the hunting and wildlife organisations in South Africa in hunting industry publications in recent months, are in large measure, incorrect.

 

In 2005 SAHGCA, PHASA, CHASA, NSA and WRSA established an alliance to serve as a caucus. This initiative evolved into The Hunting and Wildlife Associations of South Africa (HAWASA). Although member associations represent their constituencies at Government forums in their own right, HAWASA is being recognised as credible representation of the wildlife industry at government forums on conservation and biodiversity and serves as a high-level spokesperson to support individual member associations in promoting the broader objectives of their specific domain in the hunting and wildlife sector.

 

HAWASA is familiar with the real and perceived threats to the sector, including negative public perceptions about certain aspects of the industry; bad-mouthing from anti-hunt and animal rights activists and pressure groups; and politically-driven actions i.e. land reform and regulatory processes that impact on hunters and wildlife ranchers. HAWASA is in the process of realigning its strategy to deal with these threats while striving to take the lead in the green economy.

 

The hunting and wildlife sector is a dynamic environment where the goal posts shift all the time and new challenges emerge continually. Individuals in the wildlife industry can rest assured that HAWASA approaches the challenges facing our industry, in a unified manner. That is also why it is so important for hunters, wildlife ranchers, firearm owners and everybody involved in the industry in whatever manner, to belong to their local associations.

 

Reticules for Africa

Aug 5, 2013 | Optics

By Pierre van der Walt

 

crosshair Crosshair Reticule
Advantages: The fine lines do not obscure small targets at range and it therefore is a suitable for long-range application on small animals and varmints. Quite acceptable for African plains game hunting during daytime
Disadvantages: The fine lines are difficult to see in poor light or against dark backgrounds. It is a bright light only option for good eyes and slow shooting.
dot Dot Reticule
Advantages: The dot provides an uncluttered image of the target and provides a very natural point for the eye to use as reference point. It mostly provides a bit faster target acquisition than the stand-alone Crosshair. Not popular in Africa.
Disadvantages: It provides a single reference point, and if that is not visible in poor light or on dark target, then the hunter has no other means of aiming. That can be circumvented by opting for an illuminated dot. If the dot is large it limits the riflescope’s application to closer ranges or larger species.
target-dot Target Dot Reticule
Advantages: It employs the strengths of both the Dot and the Crosshair designs and provides a natural reference point that can be used under a wider range of conditions and backgrounds than the stand-alone Dot. It is a bit more visible than the stand-alone Crosshair, especially when illuminated. It is an excellent choice for shooting at round targets as in target shooting. It is fine for African plains game hunting across bush and medium ranges
Disadvantages: It provides a single reference point, and if that is not visible in poor light or on dark target, then the hunter has no other means of aiming. That can be circumvented by opting for an illuminated dot. If the dot is large it limits the riflescope’s application to closer ranges or larger species.
circle-dot Circle Dot Reticule
Advantages: The circle dot provides a large, readily visible target-encircling reference point that is very quick to acquire with a finer aiming dot providing precision if needed. It is very suitable for the hunting of moving targets at close range and is fine for thick-skinned African game, especially with illuminated capability.
Disadvantages: It does obscure more of the target and, unless illuminated, it is not much better than the normal Dot design for normal hunting
duplex Duplex Reticule
Advantages: Justifiably the most popular reticule in the New World and probably the most sensible general hunting reticule, the Duplex offers the fine central aiming point in combination with bolder sections that remain visible under most daylight hunting conditions. It also offers the tips as reference points for windage and elevation.
Disadvantages. The fine section of the reticule can still be ‘lost’ in some light and the bold sections obscure some target. This is resolved by using illuminated centre sections or the addition of a dot, black or illuminated.
cpc CPC Reticule
Advantages: It offers the advantages of the Duplex, with the additional benefit of tapered posts which are less intrusive of the sight picture. It is an excellent design for normal hunting in Africa across all ranges. Companies such as Schmidt & Bender offer a variety of German reticules options with CPC-style tapered posts.
Disadvantages. It is useable in more light conditions than the normal Crosshair, but not as versatile as the Duplex. It also does not offer any alternative aiming points to the hunter.
german-4 German #4 Reticule
Advantages: The bold posts are visible in almost any light conditions, and the absence of a heavy post above the aiming point provides a fairly good image of the target. When placed in the first focal plane of the riflescope, as often is the case with European riflescopes, the reticule size will appear to change with magnification.
Disadvantages: The fine aiming section of the reticule is very narrow and a lot of the target is obscured by the heavy posts. It is not a fast reticule to use with precision. There is a shorter post version known as the German #7
cd CD Reticule (German #9)
Advantages: A very fast and intuitive system combining the German #7 reticule with the Circle Dot. It is an excellent African dangerous-game reticule, and in illuminated configuration it does not disappear on the dark skin of pachyderms. It essentially is a short-range system.
Disadvantages: It is not suitable for long-range hunting or small game. As with all illuminated reticules, one has to be constantly aware of the state of the battery and carry extras, but battery life has improved dramatically over last few years.
german-post German Post (German #2)
Advantages: An excellent African reticule, especially on dangerous game, as it is bold enough to work in almost any light. It offers a very simple and uncluttered sight picture and can also be had configured with an illuminated arrow tip for fine aiming.
Disadvantages: It obscures the body of small targets at range. The flat top is not as precise as a sharp tip or fine line, but it primarily is a large-game, short-range reticule.
german-1 German #1
Advantages: A bold reticule that works well in poor light and jungle conditions, especially when the post tip is illuminated. It provides the hunter with better vertical referencing than the German #2 post. It is a fine large- and dangerous-game system for short-range use.
Disadvantages: The sharp tip can be lost in some light conditions and it also obscures small targets at range.
german-56 German #56
Advantages: This reticule has no notable advantage unless the dot is illuminated, in which case it offers a natural and easy to acquire reference point for short and medium ranges.
Disadvantages: It does not offer the fine aiming reference of a crosshair or post with tip at perceived point of impact. If the dot is ‘lost’ on a dark target the hunter is in trouble as he will have to guess point of impact.
trajectory-comp-custom Trajectory Compensating Reticule (Customized)
Advantages: Some companies such as Leupold offer hunters reticules with alternative elevation aiming points customized to the exact bullet and velocity combination used. This offer an uncluttered sight picture, very little guesswork, as it is only affected by atmospheric variation which is not that much across hunting ranges. Generally based on the Wide Duplex reticule, this most likely is the ultimate African hunting reticule. These reticules are best combined with a laser rangefinder for exact measurements.
Disadvantages: The reticule is bullet- and velocity-specific, and the riflescope is forever tied to a single load that may become unavailable in time, and animals do not always stand at precisely calibrated ranges. It is also costly and time-consuming to send the riflescope to the manufacturer for the retrofit. The Ballistic Turret system is most probably a better option.
trajectory-comp Trajectory Compensating Reticule (General)
Advantages: These reticules enable the hunter to predetermine reticule reference points for bullet drop at different ranges. They are fast to use provided range is known. Some, such as the Swarovski TDS (not pictured), also provide range-finding capability based on fitting the animal chest or whither height between lines and calculating the range. Having the alternative bullet-drop aiming points reduces the amount of guesswork the hunter has to engage in, and also the degree to which he has to compensate for wind or elevation
Disadvantages: Again these reticules, depending on actual design, do not always work that well in poor light. The SA Hunter depicted reticule is one of the better designs, from both visibility and simplicity perspectives.
range-finding-mil-dot Range-finding Reticule (Mil-Dot)
Advantages: The Mil-Dot enables the hunter to scale the target of known size in relation to the Mil-Dots and use the result to calculate the range to the target. The reticule itself offers enough reference points to compensate accurately from the fall of a missed shot for a precise second shot.
Disadvantages: The system requires some experience in the correct and accurate placement of the reticule on the target for the Mil-Dot reading, and is further dependent on the correct assumption of target size. It is a slow system that requires time to read and make calculations for which a calculator or reference sheet is required. It is easy to get confused by all the dots. Some designs alternate dots and bars and that improves the concept from a hunting perspective.
range-finding-animal Range-Finding Reticule (Animal-Scaling)
Advantages: Hunting-dedicated reticules employ a system whereby animals are fitted between scaling lines and the range then calculated by a variety of means. It enables the hunter to make a highly informed range estimation and offers windage referencing to various degrees. These reticules, such as on the Horus Vision versions can become very complicated and extremely cluttered. The South African Lynx RF reticule depicted works very well on African plains game.
Disadvantages: It takes a bit of time to fit the target between the correct lines and make calculations. Sometimes grass and other objects affect the ability to place the correct animal parts between the lines and that affects the accuracy of results. Depending on the complexity of the actual design, hunters have to engage in the effort to really familiarize themselves with the system. These reticules often are difficult to use in poor light.

Zero Riflescope with One Shot

Aug 5, 2013 | Optics

By Pierre van der Walt

Yes, it can be done! Assuming you have fired a fouling shot and you shoot straight.

Step 1 Set Target Up
Set a target up at the intended zero range, i.e. 100 yards.

For this method a round aiming point works best.

The full aiming point must be visible through the barrel, so it must not be too large or too small. The closer the aiming point is in size to what you can see through the barrel, the more accurate the result is
Step 2 Set Rifle Up
Remove the rifle’s bolt and place it on bags with which you can pack it down firmly. Equipment that works well for this purpose are:

 

Bullsbag X7 Modular System

bullsbag-thumb

Caldwell Lead Sled

caldwell_lead_sled_thumb
Step 3 Aim through Barrel
Centre, and by centre we really mean centre, the target in the barrel and make the rifle immovable.

Then adjust the riflescope reticule to centre on the target.

barrel-target
Step 4 Fire the Shot
Fire the shot without moving the rifle.

Remove the bolt without moving the rifle or the rest/bag and adjust the rifle to regain the exact above correct sight picture through the barrel and riflescope.

The ideal would be if no correction has to be made to the rifle, but recoil makes that virtually impossible.

Make sure the rifle is packed tight once this is achieved.
Step 5 Adjust Reticules
Now peek through the riflescope without moving anything and find the bullet impact point on the target.

Unless you are very lucky the bullet hole will be some distance from the aiming point and reticule position.

Without moving the rifle or the rest/bag, adjust the reticules to centre on the bullet hole.

Your rifle and scope are zeroed! You can verify it with a second shot.

 

Understanding Riflescope Terminology

Aug 5, 2013 | General

By Pierre van der Walt

The Human Eye

The human eye, with its restrictions and abilities, forms an indispensable part of the riflescope as a sighting system. Optical engineers are compelled to take this into consideration when designing a riflescope, thereby adapting it to the human eye.

It is, therefore, important to grasp the fundamental functioning and limitations of the eye in order to understand the workings of a riflescope.

The human eye can roughly be described as a spherical organ with a 25mm diameter. It consists of a transparent section known as the cornea. Behind the cornea one finds an aqueous-filled anterior chamber, and then the iris which surrounds the lens perimeter and also slightly overlaps it. At the back of the eye there is a reasonably large chamber known as the vitreous body. The rear three-quarters of the inside of the eye consists of a layer of light-sensitive receptors known as the retina. Insofar as riflescope use is concerned, the most important sections of the eye are the cornea, lens and the retina.

Light is necessary for sight. Light rays reflected by any object pass through the cornea and then through the lens to focus on the retina. The image on the retina is then transmitted through the optic nerve to the brain where awareness of the image takes place. The amount of light that can penetrate the eye is controlled by the diameter of the pupil. Pupil diameter is controlled by the involuntary muscles of the iris. In bad light the pupil enlarges and in good light it contracts.

The maximum diameter to which the pupil can expand is about 0.275” (7mm), and then only in pitch darkness. As soon as light passes through the pupil the lens (which has a biconvex shape) is refracted. The refraction focuses the light rays on the retina.

Aberration

Once light rays have passed through the scope lens and having been refracted by the lens glass, it moves through the vitreous body and focuses the image on the eye’s retina. The best focus occurs on a point which is in line with the visual axis of the eye. This point is referred to as the fovea. The focus at other areas of the retina is not as crisp as at the fovea, mainly because of the angle with which the incoming light rays fall on the retina and the imperfect focal points thereof. Light refracted by having passed through a convex lens furnishes a poor image at high magnification. This occurs because the light rays pass through the lens at different points and a complete image does not form at exactly the same horizontal distance from the lens. The centre of the lens has the longest focal length. The focal lengths of surrounding lens areas shorten in direct relation to the curves of the surrounding lens surface. This problematic phenomenon is known as aberration.

Several different types of aberration exist, but are not of any importance for purposes hereof. Chester Moore Hall (1703 – 1771) solved the problem created by aberration by combining crown glass (glass not containing lead or iron) and flint glass (which has different refracting indexes) in a single lens assembly consisting of a convex crown grass lens and a concave flint glass. This enabled him to focus the rays of white light on a single focal point with virtually no separation of the different rays which make up white light.

Ballistic Turrets

These are turrets on riflescopes that offer multiple zero options. In other words, the hunter can zero across various known distances. Say at 100 yards, 200 yards and 350 yards, he can simply dial the range in and shoot with less or no holdover depending on the exact range to the target.

Erector & Field Lenses

One of the most important differences between astronomical and riflescopes is that the latter sports erector lenses in order to furnish an upright image.

Apart from objective, ocular and erector lenses, modern riflescopes also contain field lenses. These lenses influence the route that light rays take through a riflescope and determine the field of view.

Light rays passing through the objective lens group are bent by the convex shape, thereby resulting in an inverted image. Because this group consists of different types of glass, aberrations are corrected and all light rays focus at the same point.

The light then passes through the erector group which turns the image upright. The erector lenses once again have a focal point where the image is in perfect focus. From here the light passes through the ocular lens group into the eye.

In order to have any use as a sight, a riflescope must have sighting mechanism. In modern riflescopes it is the reticules or crosshairs, dot, or whatever reference points has been used.

The reticules must at all times be clearly visible to the shot. There are only two places inside a riflescope where a sharply focused image of the target at all times exists and those are the focal points of the objective and erector lens groups. These focal points are the only places where reticules can be installed in such a manner that both target and reticules are well focused and appear as clear images. Once the light has passed through all the riflescope lenses it reaches a point where the shot can see everything that has been reflected on the objective lens. This point is at the focal length of the ocular lens group, and the distance between this point and the ocular lens group is known as eye relief. Theoretically, this means that there is only one critical point behind a riflescope where a shot can place his eye and see a complete and clear image. In practice, aberration comes to the aid of the shot in this regard because all the light rays exiting from the ocular lens do not have the exact focal length. It is possible to move the eye slightly to the front or the rear of the focal plane and still see a satisfying image. This contributes to fast eye alignment and reduces aiming time, both of which are very important to the hunter.

Eye Relief

Eye relief is the distance at which you can see the full image view through the scope and determines how far behind the riflescope’s ocular (rear) lens the hunter will place his eye for optimum visibility. If you move your eye nearer or further back from the objective (rear) lens, the field of view begins to constrict. Insufficient (short) eye relief will force the hunter to hold his eye close to the riflescope and he can then be hurt when recoil slams the riflescope back into his face. Long eye relief enables the hunter to safely fire hard-recoiling riflescopes without risk of injury. Eye relief varies as magnification on a riflescope is adjusted. The higher one cranks the magnification up, the shorter the eye relief becomes.

The average eye relief for centerfire caliber riflescopes is about 3” (75mm). Riflescopes designed for big bore rifles normally have eye relief varying between 3.5” – 5” (90 – 127mm), and rimfire rifle riflescopes have only 2” (50mm).

Exit Pupil

The extent to which the light rays that fall on a riflescope’s objective lens can be concentrated depends on riflescope magnification, because the riflescope’s exit pupil is determined by dividing the objective lens diameter by the magnification of the riflescope.

A riflescope with a 4x magnification and an objective lens diameter of 40mm has a 10mm exit pupil (40 ÷ 4 = 10mm). In order to fully utilize a riflescope’s objective lens diameter, its resolving power must be sufficient to create an exit pupil with the exact diameter of the human pupil under the prevailing light conditions. To illustrate: A riflescope with a 40mm objective lens requires 7x – 8x magnification to fully utilize the 40mm of lens diameter, because in early morning and late afternoon light the human pupil has a diameter of 0.197”-0.236” (5 – 6 mm). For example: (40mm lens ÷ 7x magnification = 5,7mm exit pupil and 40 ÷ 8 = 5mm).
Optical tests conducted by the Americans during the Second World War established that the human eye can contract to ±0.1” (±2,5mm) in bright light. At dusk, with a light intensity of one candlelight (stated as a candela) the human pupil diameter is 0.197” (5mm).

Suppose you are hunting on a very clear day in bright sunshine and will most likely have a pupil diameter of ±.12” (3mm) and intend using a 4x magnification riflescope. The objective lens diameter will only have to be 0.472” (12mm – 3mm exit pupil x 4 magnification = 12mm). If the objective lens diameter is any larger it will pick up reflections and images under these conditions that the human pupil is unable to absorb.
But light conditions vary, and sometimes the light is poor. Under such conditions your pupil will expand to, say 0.236” (6mm). A 12mm objective lens will absorb insufficient light under such conditions to allow optimum vision, and such a riflescope will be useless, the reason being that the eye pupil of 6mm requires a 6mm exit pupil and a 24mm objective lens (6mm pupil diameter x 4 magnification = 24mm objective lens).
It is for the abovementioned reason that no modern riflescope sports a 12mm objective lens diameter. Another reason exists. A larger diameter exit pupil enables a shot to align his eye faster and easier, because his eye does not have to be exactly behind the centre of the riflescope’s ocular lens. The drawback of unused image whilst using large objective lenses is a small price to pay for the added convenience of better vision and ease of alignment.

Very view advantages in optics come free, and the convenience of a large exit pupil on a riflescope holds the disadvantage of parallax. More about that later.

Field of View

If a hunter holds his eye at the correct eye relief distance from the ocular lens, a cone of sight stretches from the eye pupil to the rim of the ocular lens. This cone forms an angle stretching from the lens rim on the one to the eye and back to the opposite side of the lens rim. This angle is the maximum angle that can be seen through the particular riflescope and is known as the field of view. Suppose a riflescope with a 6x magnification has a field of view of 24°. The visible field at 100 metres will be approximately 37 metres. Because this distance is magnified 6x (reduced) by the particular riflescope, one must divide the distance (37 metres) by 6x. The actual field of view at 100m then is 6,16m (20.2ft). Although it sounds logical to express a riflescope’s field of view in degrees, valid for all distances, most manufacturers express the field of view as one distance at another, for example, 12,8 metres at 100 metres. This system is more concrete and easier to grasp. It means that the shot will see an area of 12,8 m diameter at a distance of 100 metres. At 50 metres he will see 6,4m (half) and at 200 metres 25,6 metres (double).

A riflescope’s field of vision can be widened in three ways:

  • The first is to reduce eye relief. The problem created by this method is that the aiming eye must be held to near to the ocular bell. Recoil can then cause injury when the scope is slammed into the shooter’s face.
  • Another approach is to reduce magnification.
  • The third and easiest solution is to simply increase ocular lens (rear lens) diameter.

Focal Plane & Reticule Position

Where reticules are placed in a riflescope affects the way in which they are perceived by the hunter. A reticule placed in front of the erector assembly (first focal plane) remains in the same visual proportion to the target across the riflescope’s entire range of magnification. The hunter will perceive this as a change in reticule thickness with changes in magnification. In reality the reticules are actually in proportion to the target. It is a system often found on European riflescopes and is not particularly liked in Africa and America, but provides good range-finding capability.

Reticules placed behind the erector assembly (second focal plane) will always stay the same size.

Fixed Power Riflescopes

Fixed power riflescopes are becoming increasingly scarcer as they do not offer the convenience of varying the magnification to suit the size of and distance to the target. Such riflescopes offer a singular magnification, but actually work very well.

Focusing Riflescopes

Not everybody has 20-20 vision and riflescopes must be adjustable to suit different eyes. Riflescope focus adjustment is effected by adjusting the ocular (rear) lens group.

Hunters without refraction errors can use a simple procedure to focus their riflescopes. Relax the eyes by looking at something distant without objects the eye can fix on, such as the cloudless sky. Turn the focus ring on the rear end of the riflescope fully to one side. Then bring the riflescope in position in front of the aiming eye and hold it at the same distance that it will be when shooting. Look THROUGH the riflescope and not at the reticules. If the reticules appear fussy or have a ghost image, adjust the ocular bell until they appear focused when executing the test. Do not keep the riflescope in front of the eye for more than a few seconds otherwise the eye will adapt. Then execute a half-turn on the adjustment ring and repeat the process until at some stage the reticules immediately appear sharp when the riflescope is peeked through.

Lens Coating

It is obvious that the more of the light that falls on the objective (front) lens that makes it out the ocular (rear) lens the better the hunter will see. A riflescope that only allows 60 % of the light that reflects on the objective lens to pass into the eye is not as good as one that allows 97% of such light to pass into the eye.

It is a well-known fact that glass does not allow all light that falls on its surface to come through. Approximately 4% of the light that falls on untreated glass is reflected at each surface where glass and air meet. This figure is equally valid for the surface where light enters glass than for the surface where it exits from glass. Because riflescopes easily contain ten lenses, 40% or more light can theoretically be lost in the process of passing through it.

The problem of light reflection and loss was largely solved by Professor Olexander Smakula (1900 – 1983) of the German firm Zeiss during the 1930s by coating lens surfaces with a thin layer of refractive fluoride and other chemicals. This process was extremely successful. These days, riflescope lenses are coated with numerous layers of chemicals, and some manufacturers claim light transmission through their riflescopes to be as high as 99%. Bear in mind that different light conditions and different eye conditions and colour-blindness levels cause hunters to experience different coatings differently. Some eyes react well to certain types of coating and others not.

Light Transmission – Relative Brightness of Riflescopes

The prospective riflescope purchaser should avail himself of two other terms – the Relative Brightness and the Twilight Factor of a riflescope. Otherwise he will be misled by the performance claimed for a riflescope in poor light conditions.

For many years most riflescope manufacturers published relative brightness indexes for their riflescopes, thereby propagating that a higher brightness factor meant better twilight performance. Relative brightness as a term bandied about is nothing but the square of the riflescope’s exit pupil diameter. The exit pupil diameter is, of course, the diameter of the light beam which exits from the ocular lens and can be determined by holding the riflescope at arm’s length. The bright spot visible on the ocular lens is the exit pupil. Because the exit pupil is determined by the amount of light which pass through the riflescope, it had incorrectly been accepted as a good method to determine a riflescope’s ability to function effectively in poor light. This is incorrect.

Simply put, the exit pupil of a riflescope can be increased by enlarging the objective lens diameter, as the exit pupil is the objective lens diameter divided by the riflescope’s magnification, i.e. 42mm (1,65″) lens diameter divided by 7x magnification = 6mm (0,236″) exit pupil. The brightness index of a riflescope with a 6mm exit pupil is 6×6 = 36. Another example is a 56mm (2,2″) lens diameter divided by 7x magnification which results in an 8mm (0,315″) and a brightness factor of 8×8 = 64. The latter’s relative brightness is 64 which is better than the 36, because the exit pupil is larger.

The relative brightness of two lenses with the same objective lens diameter will differ if their magnifications differ. For example, divide a 56mm lens by 8 magnification, and you will end up with a 7mm (0,275″) exit pupil. If you divide a 56mm lens diameter by 4X magnification it gives a 14mm (0,551″) exit pupil. The riflescope with the smaller magnification has the largest exit pupil and the square thereof will, naturally, also be the largest. Nobody can blame any hunter being under the impression that riflescopes with low magnification are better suited to low light conditions than high magnification.

The truth is that the pupil of the human eye can only open up to a certain extent: ±0.2” (±5mm) in hunting conditions. At that aperture the eye can, like a camera, only absorb and utilize a certain amount of light, being of 0.2” (5mm) diameter. A large diameter light beam cannot penetrate the pupil. Just like a 4” (100mm) pipe cannot accommodate all the water from an 8” (200mm) pipe in the same time without increasing pressure. Riflescopes cannot increase light’s pressure. So, the relative brightness figure is a useless consideration when evaluating a riflescope intended for twilight use and hunters should not be misled by it.

Light Transmission – Twilight Factor of Riflescopes

A riflescope with a high magnification is better suited to poor light conditions because it shows more detail. This is proved and measured by the so-called twilight factor (TF). The twilight factor is determined by multiplying the objective lens diameter with the riflescope’s magnification and then determining its square root.

Example 1 TF = √ lens diameter x magnification
TF = √ 32 x 4
TF = √ 128
TF = 11,3
Example 2 TF = √ lens diameter x magnification
TF = √ 32 x 8
TF = √ 256
TF = 16

The riflescope in example 2 has a higher twilight factor and is therefore better suited to hunting in poor light. What it all boils down to is that a larger objective lens diameter or a higher magnification are both positive factors in poor light.

 

Objective Lens Diameter

The size or diameter of a riflescopes objective lens is governed by the wave theory of light. Light rays move from one point to another in a wave pattern, like ripples in a pool. This causes the outline of an image to become somewhat hazy, almost as if the object is vibrating.

Because of this vibration it is, practically speaking, virtually impossible to observe an absolute perfect point image of any object through a lens. Each point of an image consists of a spot of light with a diffraction ring surrounding it. This ring is called the Airy disc. The only solution is to increase lens size, thereby admitting a greater area of the wave front and then to concentrate the same tightly for better visual resolution. This can be illustrated by drawing something on a large scale. By reducing its size, certain detail is lost, yet it shows more detail then would have been the case had it initially been drawn on a small scale. In the case of lenses this can only be achieved by using objective lenses with a larger diameter.

In order to use the image reflected on the riflescope’s objective lens, the light must penetrate the eye. The light that penetrates the eye must be concentrated in a beam with a diameter not exceeding normal pupil diameter, that being 0.275” (7mm) in pitch darkness and about 0.197” (5mm) in light suitable for hunting. If this image beam (exit pupil) is larger than the pupil, the eye will be unable to see the whole image reflected on the objective lens.

Parallax

Parallax is normally defined as the apparent displacement of an object relative to another because of a shift in the point from which the object is viewed.

This can be practically illustrated with the same example used to determine the dominant eye of a shot – with minor adaptions. Stretch an arm with the hand in the classical hiking gesture out in front of the head, simultaneously aligning the thumb with an object a few metres away whilst keeping one eye closed. Switch eyes without moving the hand or head at all. The thumb will not be lined up with the object anymore. Yet neither the thumb nor the object has moved. It is just the point or angle of observation that has changed. If the thumb is held against the object the apparent movement, because of different observation points, will be minimal or non- existent.

Parallax is one of those terms that baffle most hunters simply because it sounds complicated. In reality, the aspects regarding parallax that the hunter has to master are few and relatively simple, as it is unnecessary to understand or use any mathematical means.

The existence of parallax in all riflescopes is easily determined. Place a riflescope on a solid rest and aim it at an object about ten metres off. Then move the aiming eye horizontally to and fro behind the scope. The reticules will appear to move relative to the point of aim. Yet it is not the case. Once again it is merely the point of observation that moves.

From this we can deduct that if the aiming eye pupil is not exactly aligned with the centre of the exit pupil of the light rays, an angle is created between the eye’s line of sight and the axis of the light moving through the riflescope. This causes parallax and results in a point of impact differing from the point of aim indicated by the reticules to the off-center aiming eye.

This error is so slight that it can be ignored during short-distance hunting. The effect is more pronounced across longer ranges. A long-range hunter normally has sufficient time to align his eye properly, thereby eliminating parallax. For this reason it is important to choose a riflescope with a small exit pupil for long-distance use. Even though the manufacturer claims it to be parallax-free, it is not parallax-free over all distances. That is why a parallax adjustment feature has been introduced on riflescopes to be used at long range. If hunting distances are short or hunting conditions of such a nature that aiming time will be short, riflescopes with larger exit pupils will offer an advantage.

Although the time parallax and its effect are now understood, it remains necessary to explain the reason for its existence.

At the discussion of erector lenses it was stated that the reticules must be placed at the focal length of these lenses to present a clear image of target and reticules, and to place both on the same visual plane.
We all know that a magnifying glass must be held a specific distance from an object in order to present the clearest image to the eye. In layman’s terms it can be said that the moment the magnifying glass is moved away from that point, the focal length does not coincide with the viewer’s eye and the image blurs. A riflescope has the same effect. Because the reticules cannot be moved around in the scope due to design, it follows that the lenses must be calibrated to form their focal points at the reticule position. This, on the other hand, means that the relevant lens group can only be a specific distance away from the target.

Riflescope manufacturers, therefore, choose an arbitrary distance for the target according to where the lenses are calibrated to have the correct focal length. In riflescopes intended for centerfire hunting rifles this distance normally is 100 metres or 100 yards.

The hunter virtually never finds a target at exactly the distance his riflescope is calibrated for and so the focal point inside the riflescope does not form exactly at the desired point where the reticules are situated. This results in the reticules and the image not being on the same plane. The same phenomenon as with the thumb example occurs when the point of observation is moved. Parallax occurs. The nearer the distance between the target and the relevant lens is to the arbitrary 100 metres, the nearer to the desired point the focal point forms and the smaller parallax becomes. The further beyond 100 metres the target stands the progressively more pronounced parallax again becomes.

Some riflescopes, especially high magnification target and silhouette riflescopes being used over known distances, are fitted with an external adjustment ring on the objective bell or a parallax adjustment knob on the turret. This enables the shot to focus the riflescope for each distance over which the riflescope is used in order to eliminate parallax.

Rangefinding Reticules

These riflescopes were originally developed for the military and originally employed a so-called mil-dot system in terms of which the sniper bracketed his target between the cross on the scope reticule and a series of dots, and then calculated the range to the target. It is quite accurate.

Civilians generally do not take the trouble to master the mil-dot system and a variety of simpler systems have been developed for them. This ranges from bracketing animal bodies between sets of lines to a variety of other systems. The advent of portable laser rangefinders has largely eliminated the need for this kind of system, but it remains popular for some reason.

Resolving Power – Human Eye

The resolving power of the average human eye is about one minute, or a 16th°, which means that a normal and healthy human eye can distinguish an object (say blocks on a chessboard) of about 1” (25,4mm) in diameter at 100 yards. If the chess board is moved further afield, the human eye will find it progressively more difficult to distinguish each square until a point is reached where the chessboard will appear grey.

 

Resolving Power (Magnification) – Riflescopes
The resolving power of a riflescope is the relationship between the riflescope’s magnification and the human eye’s resolving power. A riflescope with a 4x magnification will enable the human eye looking through it to distinguish a square (or any object for that matter) over four times the distance the naked eye is able to. Put differently: Over any given distance such a riflescope will enable the shot to distinguish a square a quarter of the size that the naked eye can. The ability of any riflescope to distinguish an object and its details depends on:

  • The type of glass used;
  • The quality of such glass;
  • The degree to which aberrations have been corrected;
  • The diameter of the objective lens.

As a result of modern technology there is a large number of types of optical glass in existence, each with its own properties. Quality and uniformity of the end product depends on the ability of the manufacturer to maintain batch-to-batch consistency.

Trajectory Compensating Riflescopes

See Ballistic Turrets above. Such riflescopes are specifically designed to change the point of impact according to the distances over which the shooting is done. These riflescopes contain certain distance settings. In other words, it is adjustable for distances like 100m, 200m, 300m and so forth. Such a riflescope is sighted in at say 100m and can then be calibrated to be on target at any of the other distance settings when adjusted.

Variable (Power) Riflescopes

A variable power riflescope offers the hunter a range of enlargements (magnification options). If he hunts at close range or large animals, the hunter can reduce the magnification and, if the animal is small or distant, he can increase the magnification to see the target much more enlarged.

 

This will close in 2 seconds

Powered by  GDPR Cookie Compliance
Privacy Overview

This website uses cookies so that we can provide you with the best user experience possible. Cookie information is stored in your browser and performs functions such as recognising you when you return to our website and helping our team to understand which sections of the website you find most interesting and useful.