Well-made, but less than ideal for non-military users.
Source: bought it new
Price Paid: $88
Well-made, but less than ideal for non-military users.
- Air-filled compass housing can't develop a bubble
- Self-luminous tritium lighting
- Excellent manufacturing and assembly quality
- Deep-well compass housing for multiple magnetic zones
- Mediocre accuracy
- Mediocre shock resistance
- Degree scale in 5-degree increments only
- Can fog over in certain conditions
- Compass dial slow to settle
The U.S. M-1950 dry lensatic compass currently made by Cammenga in the 3H configuration is lauded as being the toughest, most accurate compass on the market. After all, the U.S. military uses it, so it must be the best, right? Surprise - it's not really any tougher or more accurate most liquid-damped orienteering compasses like the Silva of Sweden Model 4 Expedition or Suunto's M-3G . Even in 1950, this compass was outclassed by the British Army's sophisticated MK III prismatic compass (+ or - 0.5 degree accuracy). And in the civilian world, things have changed a lot since then.
It's true that Cammenga's version of the M-1950 compass has a super-strong case and housing, and can't develop an air bubble since it's a dry card (induction dampening) design. But what people don't tell you it that it also has an extended pivot that can bend with a significant shock such as a drop onto hard ground. Once the pivot is bent, the dial will not produce repeatable, accurate readings. Note the official military 'shock' test — an easy 'drop test' of 90 cm (3 feet) onto a table covered with a 10cm (4-inch) layer of plastic-covered sand.
The M-1950 lensatic compass design is also frequently extolled for its superior accuracy over most orienteering-style compass designs in shooting an azimuth (taking a bearing) to an objective or landmark. Let's examine that.
The compass dial is in both mils and degrees, and as the military uses mils, the degree scale is given second place on the dial. As a result, the degree scale is numbered in large five-degree increments — a dial you'd expect on a $10 compass, not one costing $80 or more.
You can, if you practice, split the five-degree increment spacing in half to get a (theoretical) reading of 2.5 degrees between increments, while simultaneously holding the compass steady and the sighting wire fixed on the objective, then checking for parallax error — not easy. Or you could use the mils scale and convert each and every azimuth (bearing) you take back into degrees for the benefit of your companions (all of whom will have degree scale compasses).
But why bother, when other compasses have easy-to-read dials that can be read to 1 degree or less with ease? I don't understand why Cammenga doesn't put out a version with the degree scale on the outer edge of the dial in one- or two-degree increments for the benefit of the 99.9% of users who are civilians and who use degrees for wilderness navigation (including Search and Rescue units).
Besides that, there is the issue of inherent accuracy. Brand-new, the G.I. M-1950 lensatic is only required to achieve an inherent accuracy of + - 40 mils (2.25 degrees) from actual azimuth (milspec). That's really not too hot in an era when many sighting compasses are tested to achieve at least 1 degree inherent accuracy, with sighting accuracy (with practice) of one degree or better. Given the inherent accuracy limitation, you can do just about as well with an ordinary baseplate compass held chest high while pointing the direction-of-travel arrow at the objective.
Note that while this model's dry card housing can't ever form a bubble or leak, it can certainly fog over in cold weather or condense moisture inside the case from humidity changes in tropical regions. Why? Because the interior is filled with ordinary air instead of an inert gas like your fogproof binoculars or rifle scope.
The compass uses magnetic 'induction dampening' to settle the floating dial in 'six seconds or less'. Fine, except that in comparison, my liquid dampened Suunto compass with 'global needle' settles in less than one second, and stays rock-steady, with no wobble. Because the latter is a gimbaled design, I can even take accurate compass readings while walking or riding in a small boat or canoe.
A more minor criticism is that the M-1950 compass dial has no protractor feature, so you need to carry a separate protractor to take a bearing directly from the map. It has no romer scales, and only one 1:50,000 metric scale, which isn't much use for USGS 1:24,000 topos. It also has no adjustable declination feature for relating all compass headings to true north. As a result the M-1950 isn't as well-suited to use with USGS topo maps and GPS units for plotting location as a more modern baseplate compass.
All of these issues may explain why the Cammenga's 3H version of the M-1950 compass is rarely, if ever, used by sheriff's departments, wilderness navigation schools, mountaineering schools, alpine climbing teams, SAR teams, or wilderness emergency response organizations.
The compass itself is built with attention to detail and all parts on my example were well-fitted with no signs of manufacturing or assembly defects. Cammenga does an excellent job on meeting milspec standards.
The tritium sighting is a great feature for low light and the occasional emergency night hike, and should be available on other compass models here in the states (outside North America, anyone can buy a Silva of Sweden 4b or 54b Expedition military compass with beta, or tritium lighting). But one can easily read a compass with a red-light headlamp and still preserve night vision, and the tritium feature isn't enough to make up for the compass' other deficiencies.
In summary, the M-1950 lensatic compass in 3H configuration as made by Cammenga is a special-purpose military compass that needs a redesign to compete as a general-purpose wilderness navigation compass.
Durable and accurate. I bought one of these as a replacement…
Source: bought it new
Price Paid: $79.95
Durable and accurate.
- Easy to read
- Heavier than most.
I bought one of these as a replacement for an old Silva compass. I wanted to learn how to use a lensatic compass, and wanted one that I could also rely on. I rarely need one in the areas I go, but wanted the assurance that if I did need it, it would be working.
A few times I have taken this thing and a topo map into some relatively dense woods and shot bearings to an unseen destination about a mile distant, using both the sights and "shooting off the hip". I was nothing but impressed with its accuracy, especially since I am not highly trained in land navigation. I had my GPS also, but buried it in my pack to prevent cheating.
Once I downloaded the track to my PC I was surprised how straight the navigation was, including four 90 degree turns 100 to 200 yards apart to route myself around a swamp. (Walking a straight line in any forest with no clear target in sight is always a challenge.)
I think the biggest benefit of this compass is how easy it is to read and follow a bearing. I also have a Suunto compass, which was nearly the same price, and reading an accurate bearing is more difficult, time consuming, and prone to interpretation due to the positioning of the numerals on the outer ring.
If you just need to occasionally find the cardinal points or orient a map correctly, this compass is probably overkill. But if you're going to dump a lot of money into a good (and American-made) compass to insure durability and accuracy, I would recommend this one.
Wild Floods had swept our backpacks once when we were…
Price Paid: Second One US $52
Wild Floods had swept our backpacks once when we were walking in the rainforest. 2 compass were with us, a European baseplate one and a 3h Cammenga one.
The baseplate was broken from a few drops, while the Cammenga was with us throughout the walks and has helped us back to the main camp.
Cammenga is very rugged and can stand all abuses we had during our lost. It was once thrown to a large king cobra approaching to our fires. Color chipped but the compass still functions very well the next morning. At present all of us are carrying one 3H to all our outings.
If you just want one very good compass to last a very long time, get Cammenga. Easy reading too. Invest just once and for all.
As far as compasses go this one is the best I have…
Price Paid: $79
As far as compasses go this one is the best I have ever used in the past 25 years from the Boy Scouts to the Marine Corps to civilian use. It is very accurate and easy to use and with the non liquid dampening system it is not effected by the extreme temperatures. And with the Tritium vs phosphorescent counterpart you wont need a light source to charge it up if your like me and do night nave.
Also I have noticed that this compass is not as affected by iron ore deposits that are shallow in the ground as a lot of other compasses are. It is a bit heaver than you average compass but it worth the extra weight for a piece of mind
This is one of those gear items that gets transferred from my regular back-pack to my day-pack depending on if I am going camping or just a hike but it always goes with me. I would definitely recommend either one of these compasses to any one.
The 3HC model is Tritium and the luminescent never need charging for ten years then you replace it (note the compass will work just fine but with no or little luminescent)
The Model 27 is phosphorescent and will need to be replenished every few hours by a light source but it will never stop working and is significantly cheaper than its 3HC counterpart but will do the job just as well and as accurate.
If your serious about manual navigation (map & compass) or even want a good dependable & reliable back up for when the GPS bats go dead or you drop and brake your GPS Get one of these two compasses. You cant beat the reliability.
I have done land navigation at many different places…
Price Paid: Gift
I have done land navigation at many different places around the world. Many were unpleasant where accuracy was/is critical. As a cavalry scout the ability to have excellent land navigation skills is a must.
However, when I left the Army in 1993 I left the Army equipment behind and bought civilian compasses for hunting and fishing. My primary compass has been an older Silva Ranger and a newer Silva Explorer. They have have been good solid compasses which is more than adequate for what I have been doing.
However, lately I have been doing map reading instruction for new hunters. I wanted something more dependable than my old standby - the Silva's. So I asked for a Cammenga 3H (basic Army compass)for Christmas.
What a difference! First, off it was like coming home again. Everything just felt right about it.
Secondly, the ability to easily navigate in really difficult terrain is far better and more accurate. With the thumbhole holder it is easier to level.
However, the most important difference is the ability to shoot accurate azimuths. The Silva was good but the 3H is far better. I like the locking card, the tritium dial and the maginifier. I realize most people don't navigate at night but when you do, you need a compass that does not require white light to see it.
Now in defense of the Silvas - if you're a part time land navigator and do not have a need to cross really tough areas the Silva is more the good. However, if you're going to navigate in situations that could end up being survival situations, spring for the 3H.
What kind of situations are those? Well, skiing/snowmobiling in back country areas far from any man made land marks (no Virginia, they don't have cell phone coverage out there!). Low areas where you must constantly shoot accurate azimuths, etc.
Just a word of caution. Most people will waste there money if they buy a 3H. It is much more than most people need. In fact a Silva Explorer is perfect for most backpackers, etc. However, if you really want the most dependable, accurate and tough personal compass this is it.