If you are interested in purchasing a high quality lensatic compass the choice is easy. Cammenga (any model) is THE brand to get. I have had a couple cheap ($10-$20) lensatic compasses over the years that I would not recommend. My advice is don’t bother until another company decides to challenge Cammenga’s dominance in the lensatic compass field. Click on the links to take a look at (or buy) these at Amazon.com.
Cammenga Model 27
The Cammenga Model 27 is the basic (and, in my opinion, best) model that Cammenga makes. It uses long-lasting (1-2 hour) phosphorescence to illuminate some of the markings on the compass for reading it at night. It’s a heavy (well, less than 6 oz. at least) and bulky-not something you want to have in your front pocket while hiking around, but those are the same characteristics that make it a nearly indestructible instrument that is likely to last as long as you do.
The compass card (lensatic compasses use cards rather than needles) is marked in degrees and mils. Mils, which are finer compass increments than degrees, are used by the U.S. military for, among other things, precise targeting. The military is a major purchaser of Cammenga compasses.
Another feature of the compass is the electromagnetic induction dampening system. This set-up eliminates the need for a fluid-filled capsule and the risk of losing the dampening system when you drop your compass on a rock.
These compasses cost around $50 and come in an olive drab color and with a 1 year warranty.
Cammenga Models 3H, B3H, and C3HRT
The 3H is essentially the same compass as the Model 27 with two differences. First, it uses radio-active tritium to produce nighttime luminosity (for about a decade) with no need to “charge” from sunlight. The second difference is the price. It costs about %40 more than the Model 27.
Personally, I prefer to be in my sleeping bag after the sun goes down, but if you do extreme cross-country expeditions or other “activities” that require some nighttime navigation, you might consider going for the tritium.
The B3H is the black version of the compass. Cammenga markets these to agencies whose employees are very color coordinated and like their gear to match their outfits (S.W.A.T., D.E.A, F.B.I. etc.).
The C3HRT is also the same 3H tritium compass but with a Real Tree Camo finish. I wonder how many of these have been lost in the woods so far…
Serious outdoor enthusiasts are divided on the question of whether to pack a lensatic or baseplate compass. Here’s a quick rundown of the differences between these two types of compasses in terms of ease of use, precision, and packability to help you take sides.
The Difference Between a Lensatic and Baseplate Compass
A baseplate, or protractor compass, has a clear, plastic base that can be used as a protractor on a topographic map, and a magnetic needle that swings in a capsule filled with fluid to dampen quick movements of the needle. The most accurate models have a folding mirror that allows the user to read the compass (reflected in the mirror) while sighting distant objects.
A lensatic compass uses a lens to allow the user to read the compass bearing with just a quick downward glance while sighting. These compasses generally use a magnetic disk rather than a needle, and dampening with either fluid or, in the best models, electromagnetic induction.
Ease of Use
Both types of compass require a little study and practice, and neither have a clear advantage in ease of use. The lensatic compass may have a slight advantage in initial comprehension for beginners because the direction seen through the lens is always the way you are facing. With a baseplate compass, the dial (bezel) has to be set before the bearing can be read. A disadvantage of the lensatic is the lack of a magnetic declination adjustment—this correction has to be done mentally, which is not a big deal, but introduces an additional opportunity to make a mistake.
Used properly, both types of compass can produce reasonably precise readings, but the lensatic compass has a slight edge. The narrow, magnified field of view seen through the lens, with just a glance down to read the direction, is a powerful combination. However, for most outdoor recreational activities like backpacking and hunting, a degree or so extra precision probably isn’t going to be the deciding factor.
Weight and bulk are factors to consider, especially if you do long-distance backpacking, lightweight expeditions, or any other activity where every ounce makes a difference. High-quality mirrored baseplate compasses weigh less than 3 ounces and have a slim profile of just over a half inch. The rugged, aluminum Cammenga Model 27 is twice the thickness and twice the weight, but it is very durable, and has no liquid, so leaks are not an issue.