Compass

Posted by: Outdoor_Quest

Compass - 10/18/10 04:27 PM

I am looking for the manufacturer of the military style lensatic compass.

Any info on source and price would be helpful.

I have seen a few cheap knock offs but they look pretty junky.

Also looking for a wholesale source for Mora knives in the US.

Thank you for the assist.

Blake
www.outdoorquest.biz
Posted by: BorkBorkBork

Re: Compass - 10/18/10 06:25 PM

Cammenga ?
http://www.cammenga.com/cammenga-products.php?category=1
Posted by: comms

Re: Compass - 10/18/10 08:05 PM

without looking at mine at home, that sounds right.
Posted by: falcon5000

Re: Compass - 10/18/10 08:46 PM

I own the CammengaŽ Military Lensatic Tritium Compass, best compass I have ever owned, used them in the military and bought one later. Tough as nails and field proven. You can't go wrong with a Cammenga.

http://www.uscav.com/productinfo.aspx?productid=7586&tabid=548
OR
http://www.uscav.com/productinfo.aspx?productid=7587&tabid=548
Posted by: Am_Fear_Liath_Mor

Re: Compass - 10/18/10 10:40 PM

Francis Barker M73 Lensatic Compass NSN: 6605-99-768-3792 (degrees)

They are very expensive though at around $400

Posted by: ILBob

Re: Compass - 10/20/10 04:05 PM

I bought a cheap one at Wal-Mart. $7 I think. It points north just as well as a $100 compass does.

It may not take being run over by a tank, but since it is on my person if it gets run over by a tank, it is likely I have more issues than whatever damage that might do to the compass.
Posted by: Jeff_M

Re: Compass - 10/20/10 04:38 PM

Originally Posted By: Outdoor_Quest
I am looking for the manufacturer of the military style lensatic compass.


Blake:

Just being nosy, but what are you planning on using that compass for? Lots of folks were trained to use them by Uncle Sam, but a lot of us have transitioned over to orienteering style compasses for general field navigation with topographic map and compass.

I like the Silva Ranger, myself, but Silva makes a decent Lensatic compass at a very affordable price, too.
Posted by: Outdoor_Quest

Re: Compass - 10/20/10 05:34 PM

Jeff,

I am using a baseplate compass and have the Silva Ranger too.

I teach map and compass classes and ocassionally a student will bring in the lensatic type. Generally the lensatic brought it are not of good quality and are not suitable for military use.

Hence my question.

I find that the baseplate compass is easy for most folks to learn to use and can be quickly adjusted for declination.

All the best,

Blake
www.outdoorquest.biz
Posted by: jzmtl

Re: Compass - 10/20/10 06:08 PM

Something to know about Silva in North America, they are knock offs made in Inida, not real Swedish Silva. A few reviews I have read say they are of poorer quality compare with the real deal. Doug has a paragraph about it on main site but I can't find them at the moment.
Posted by: Jeff_M

Re: Compass - 10/20/10 07:47 PM

Mine may be so old it pedates that. Donno, but the little pointy thing still points to Canada!
Posted by: Jeff_M

Re: Compass - 10/20/10 07:57 PM

Blake:

Why do your students say they like their lensatics? Are you training military folks? I've often wondered why the military stays with lensatic compasses, other than the angular mils thing (handy for measuring distance, used in artillery plotting, etc.), which is also available on baseplate compasses. I've also wondered about the basic map and compass proficiency of the average platoon leader in the era of GPS. Please forgive my curiosity, as I confess to being a bit of a compass geek.

Jeff
Posted by: thseng

Re: Compass - 10/20/10 08:08 PM

Honestly, the main reason I like my GI lensatic compass is the inductive damping - no liquid to leak/form bubbles/get sluggish in the cold.

The main drawback is it is not convenient to use it as a protractor to transfer an azmuth directly to or from a map.

The reason for a lensatic compass is to be able to accurately sight a bearing/heading. The best you can do with a baseplate compass is hold it against your chest and rotate your body until the needle is "caged" and then look up straight ahead.

Although that's probably good enough for most uses.
Posted by: Fox10

Re: Compass - 10/20/10 09:19 PM

I'll stay with my Suunto Mirrored MC-2 Global. Plenty of accurate for me.

John
Posted by: hikermor

Re: Compass - 10/20/10 11:25 PM

The plain fact is that for most outdoor applications you really don't need great accuracy in a compass.
Posted by: JBMat

Re: Compass - 10/20/10 11:54 PM

I carried two compasses during my time in the military. The issue one, because they gave it to me and it glowed in the dark; and a civilain cheapo around my neck I usually carried to check azimuths on the go.

And Jeff, I learned early on, LT + compass + map= lost waiting to happen.
Posted by: comms

Re: Compass - 10/21/10 03:08 AM

Originally Posted By: JBMat
And Jeff, I learned early on, LT + compass + map= lost waiting to happen.


Hey now! I resemble that remark. At least the LT part of it. BTW, the equation is not necessarily wrong but that is why PSG's carry a compass too...and usually don't stay within ten yards of a PL. They're so shiny and new that they cancel any Grid to Magnetic adjustment. (Or maybe they just forget to do the declination before moving)

In full disclosure, I was seven years infantry before OCS, so when snap judgments were made seeing my glaringly shiny butter bar, the subdued tabs and unmistakable pumpkin patch on my left blouse pocket tended to stop the snickers fast. lol.
Posted by: Outdoor_Quest

Re: Compass - 10/21/10 03:23 AM

Jeff,

Just a few bring those lensatics in.

Most folks have very limited Navigation skills and are a bit confused as to how a compass works. They are more than ready to use a baseplate once they see it work.

I like the Brunton 8010G.

The Suntoo baseplates are very nice too.

Blake
Posted by: Jeff_M

Re: Compass - 10/21/10 03:47 AM

Thanks, Blake. I imagine it helps to have various types to demonstrate for comparison purposes. I know afew guys who still swear by their old GI issue lensatics. I friend of mine (ex-SF type) teaches, as a civilian contractor, at the Army ranger school here; I was wondering if you were doing that type of work, too.
Posted by: KenK

Re: Compass - 10/21/10 10:22 AM

My own favorite compass (considering features, cost, and quality) is the Suunto Leader M-3 without the global needle (pointing to Canada is just fine - I don't need it to point to Norway or Siberia).

I've had mine for many years and no problem with bubbles. Plus, at that price (about $20-$25) I can replace it, if needed, without too many tears.

I also like the Brunton 15TDCL (the original Ranger 15)a lot, but it is a much higher cost ($50). The mirror is a good multi-purpose survival device.

Ken
Posted by: MDinana

Re: Compass - 10/21/10 07:03 PM

Originally Posted By: comms
Originally Posted By: JBMat
And Jeff, I learned early on, LT + compass + map= lost waiting to happen.


Hey now! I resemble that remark. At least the LT part of it. BTW, the equation is not necessarily wrong but that is why PSG's carry a compass too...and usually don't stay within ten yards of a PL. They're so shiny and new that they cancel any Grid to Magnetic adjustment. (Or maybe they just forget to do the declination before moving)


Off topic for a moment, but is declination *really* needed? Most of the topo maps I've seen have a Mag North and a True North imprinted. I just tend to use the Mag north as my reference and ignore declination. I get a yardstick, continue the MN arrow until is hits the end of the map, and draw parallel lines from there. That way my compass can be placed on those lines, orient the map, and away I go.

am I wrong to be using it like that?
Posted by: Outdoor_Quest

Re: Compass - 10/21/10 07:26 PM

Originally Posted By: Jeff_M
Thanks, Blake. I imagine it helps to have various types to demonstrate for comparison purposes. I know afew guys who still swear by their old GI issue lensatics. I friend of mine (ex-SF type) teaches, as a civilian contractor, at the Army ranger school here; I was wondering if you were doing that type of work, too.


Jeff,

Rarely get to work with the military which is too bad. I am retired Navy and miss all the great people I worked with.

I mainly teach classes to hikers,hunters, and SAR team members.

The few SAR teams that I work with rely on the baseplate type heavily.

Blake
www.outdoorquest.biz
Posted by: BorkBorkBork

Re: Compass - 10/21/10 07:27 PM

@MDinana
Doing that, you are actually adjusting for declination
Posted by: Am_Fear_Liath_Mor

Re: Compass - 10/21/10 07:46 PM

Quote:
'Off topic for a moment, but is declination *really* needed? Most of the topo maps I've seen have a Mag North and a True North imprinted.'


The method you've described relies on the assumption that the Mag North and True North on the map doesn't vary through time. You wouldn't want to rely on this method using an old map for the Alaskan region for example as the magnetic pole will have shifted quite considerably depending on the age of the map.

With Grid mapping systems it is even easier. You work out the magnetic declination (time varying) to true north which will also have a true north to grid north adjustment angle as well (this being fixed and not subject to time change). Add or subtract to give the Magnetic variation with respect to the map grid then use the magnetic variation with respect to the grid north lines to compensate for measured azimuths from the compass and visa versa. This ensures more accuracy and when using a baseplate compass very little pencil and protractor work is required i.e. line up the edge of the baseplate from where you are on the map to where you want to go, rotate the inner bezel until the internal lines within the compass bezel are running parallel with the map grid northing, read of the compass bezel angle and adjust for the Mag to Grid variation. When the compass needle is pointing north on the compass bezel you move off in the direction the baseplate is pointing.

You can usually get this whole process done within a few seconds with practice.


BTW depending on the scale of the map with the grid system. The variation of Grid North to True North may be slightly different depending on which part of the map you are working on. The map should indicate this so that you can accurately determine the Mag North to Grid North Variation.

And if using a GPS system always using the appropriate GPS datum system conversion to match the map grid system you are using. i.e OSGB, WGS-84 etc. Getting the wrong datum can lead to significant errors in navigation. Also the GPS needs to know the Grid to Mag variation as well. Some GPSs do not calculate this variation automatically for you.

Even with a GPS to tell you where you are (very accurate), GPS systems are not really to great at telling you which direction you should head of in (not very accurate). A map and compass is more accurate in this respect.

Posted by: MostlyHarmless

Re: Compass - 10/21/10 09:06 PM

Originally Posted By: Am_Fear_Liath_Mor

Even with a GPS to tell you where you are (very accurate), GPS systems are not really to great at telling you which direction you should head of in (not very accurate). A map and compass is more accurate in this respect.


The only time I see this as having any practical implication would be covering vast distances in landscapes where the terrain does not dictate where you go. Flat plains and such, where being slightly off course may mean many miles extra traveled.


My world isn't a flat plain, and I am quite happy with the fact that if I move 10 meters my GPS will tell me the difference between my line of movement and my target. Both visually (at the screen) and with numbers, if you prefer that. Time/distance wasted due to zigzagging around the "perfect" course doesn't matter because the terrain dictates that you can't move in a perfect line anyway.


How accurate do you need your course to be? At my GPS I can at any time see the difference between the shortest available path from A to B, my track and the direction from my current location to my target. Heading off in the general direction of my target and then adjusting my course according to the GPS display is certainly good enough for me.


The only thing a GPS isn't doing very well is aiming at the horizon and finding a good visual target in the direction you want to go. The way I see it, there is less need to do this when you use GPS as primary navigation.


But GPS skills does not render compass obsolete! If you use GPS and really want to pick a visual target that is EXACTLY in the direction you want to go - then take the numeric course value from the GPS, add it to your compass (with adjustment for true v.s. magnetic north) and aim at the horizon ... Problem solved.

Map, compass and GPS complement each other nicely.
Posted by: Am_Fear_Liath_Mor

Re: Compass - 10/21/10 09:48 PM

I guess it depends on the GPS in question and the precision of the navigation required.

http://www.youtube.com/watch?v=CJyt3RFycsE

Although mapping GPS devices are constantly improving, ensuring that the correct GPS Datum and Grid Mag variation are programmed properly, even the most expensive mapping GPS systems don't generate a truly accurate bearing to follow unless they have an electronic compass built in (again these are only usually accurate to +- 2 degrees. GPS firmware can give a reasonable indication once you are on the move using velocity filtering but if you are under cover or the number of satellites begins to vary (affect HDOP) this can effect your positioning making your position jump around (i.e. even up to +- 100m) giving inaccurate compass bearings to a nearby waypoint when standing still. I basically don't trust GPS compass information to say with confidence as to the direction to move off in to a way point (unless a built in electronic compass is in use rather than pure GPS)- there is just to many things that need to be right to point you in the correct direction not including the fact that GPS information is slow as indicated in the video.

An experienced orienter would have finished the course using map and compass by the time the waypoints had been programmed into some of these GPSs.

EDIT;


As a little experiment I took my GPS (a Garmin Camo) and set my position as a waypoint called 001 (I was using the GPS indoors so had no WAAS PRN and could only find 4 PRNS to generate a fix, which simulated heavy foilage coverage. I then programmed the GPS for another waypoint 002 directly North which was 200 metres away then turned off the GPS for 5-10 minutes.

Switching the GPS back on and allowing the GPS to again aquire a fix showed that the waypoint 002 was now showing a bearing of 332 degrees and was 182 metres away rather than being directly North @ 0 degrees 200 metres away i.e. a 28 degree error. A significant azimuth error.

GPS receivers also are subject to errors just as a map and compass work are for the the unaware, the problem is that the technology is seen by many as being 'fool proof' and leads folks into a false sense of security leading to potentially disastrous results.

Posted by: JerryFountain

Re: Compass - 10/22/10 03:55 PM

[/quote]
Off topic for a moment, but is declination *really* needed? Most of the topo maps I've seen have a Mag North and a True North imprinted. I just tend to use the Mag north as my reference and ignore declination. I get a yardstick, continue the MN arrow until is hits the end of the map, and draw parallel lines from there. That way my compass can be placed on those lines, orient the map, and away I go.

MDiana,

Do NOT use this unless you have checked the angle with current. The USGS specifically states that the arrows are NOT drawn to match the declination. There can be significant error this way. If you want to use this technique then use a protractor or baseplate compass to draw the angle from a True North line on the map.

All,

I have used a Brunton Pocket Transit for about 45 years and use it for everything but orienteering. A baseplate is designed for that. It (like the lensatic) is not ideal for lots of things and overkill for most, but I regularly use all the features and at work need the accuracy so I use it even when other types would be better.

The best,

JerryF
Posted by: JBMat

Re: Compass - 10/22/10 07:57 PM

Almost 30 meters deviation over 200 meters is basically unacceptable. You'd totally miss a tent/shelter in whiteoout conditions with a lousy reading like that. Another reason why map and compass will continue to be a necessary skill.

Way back when, when I was a Scout - my dad constructed a compass course in the 6 acres in our backyard. The course started and ended at the same spot. It was hilly and forested. The scouts were taken to the start point, aimed at the first Check Point, took an azimuth and paced out the distance. There were 15 checkpoints over a 2k course, more or less. The scouts then would plot the points using azimuths and distance to see if they could come close to the starting point. IIRC, most were within 20 meters, with some less than 5m off.

I found that using a military compass with mil reading helped a bit, cut my error down to 2m. Never really did get much better than that.
Posted by: Art_in_FL

Re: Compass - 10/22/10 10:47 PM

Originally Posted By: Jeff_M
Lots of folks were trained to use them by Uncle Sam, but a lot of us have transitioned over to orienteering style compasses for general field navigation with topographic map and compass.


Most everyone I knew who didn't have a need for a mil scale compass voluntarily handed in the USGI lensatic compass and bought a Silva. USGI compasses are bulky and heavy. Losing one, it happens, I've lost gear in a swamp (kerplunk ... gone forever), can be problematic. I've been told that they can charge you several hundred dollars for replacement. Lose the Silva and Uncle Sugar doesn't say much. You are out $17.

Tip - If you use a Silva style compass around water it can pay to tie a bit of bright foam, sold in sporting-goods stores as fishing floats, to the lanyard so they float and are easier to find if dropped.

USGI lensatic compasses, and other gear that is too heavy to save with a small float, like a SAK, benefit from a 'dummy cord' that attaches the equipment to your belt.
Posted by: MDinana

Re: Compass - 10/23/10 12:38 AM

Originally Posted By: JerryFountain


MDiana,

Do NOT use this unless you have checked the angle with current. The USGS specifically states that the arrows are NOT drawn to match the declination. There can be significant error this way. If you want to use this technique then use a protractor or baseplate compass to draw the angle from a True North line on the map.


Wow, that's interesting. I always was taught that their little MN/TN diagrams were accurate (at the time of publication). You're saying that it was likely just standard diagram, with the declination correction put in for the appropriate area??? That's pretty scary if true, since I don't recall EVER seeing that on the map itself.

AMLF, most of the maps I used were within 10-20 years. Fortunately, that's usually not too long for the pole to move. Plus, as someone said, my world isn't flat, so I checked pretty often. I also tend to stick with trails. When off trail (base camp, usually), I'm pretty good with landmarks for my goofing around.

Sounds like I've got the gist of it, but certainly potential for error.

Oh, and I still don't have a GPS... one less thing to fail smile
Posted by: Jeff_M

Re: Compass - 10/23/10 01:04 AM

Originally Posted By: MDinana

AMLF, most of the maps I used were within 10-20 years. Fortunately, that's usually not too long for the pole to move.


Lately, the magnetic north pole has been shifting west at dozens of miles per annum.
Posted by: Am_Fear_Liath_Mor

Re: Compass - 10/23/10 01:34 AM

Quote:
Lately, the magnetic north pole has been shifting west at dozens of miles per annum.


You've gotta get prepared for that Mayan 2012 pole reversal. grin

http://www.youtube.com/watch?v=5RPM27TuOqk

Just needs that huge Mass solar ejector to give it a nudge. wink



Huge ring of sun spots were forming on the sun about a week ago.

Couldn't see any of those darned obelisks though.
Posted by: comms

Re: Compass - 10/24/10 03:20 AM

dont worry about the Mayan end of the world on 12/12/12 thing. the 3 guys who came up with that deal based on a single paragraph of tablet just said that they were off by as much as 200 years.

Is it a co-incidence that they state this two years before the date and they are all still alive? you decide.
Posted by: KenK

Re: Compass - 10/24/10 02:02 PM

Outdoor Quest had mentioned the Brunton 8010G. That is an excellent compass, especially for the money. As I recall I chose that model to present to a group of Cub Scouts graduating to Boy Scouts. I think its about the equal of the Suunto Leader M-3 (which is what I latter chose to present to my own son's den when it graduated to Boy Scouts).

The Brunton doesn't require a screw driver to adjust the magnetic declination. That might be more convenient, but it also could get bumped out of adjustment, but not likely. I do worry about the screw head eventually getting damaged enough to not work, but it would seem that would take several lifetimes.

The only thing that frustrates me about the Brunton 8010G (and its minor) is that the mark where you read the angle could suffer from parallax problems since the bezel is raised off of the baseplate. That's probably not a big deal for most users.
Posted by: JerryFountain

Re: Compass - 10/24/10 03:09 PM

The Brunton baseplate compasses are made by Silva in Sweden, some of the best around. The 8010 and 9020 are among the most cost effective compasses for most users who do not have specialized needs. Personally I do not like the declination scales, I much prefer an adjustment. I have not had problems with the Brunton "no tool" adjustment but I do check them every time I use them.

The best,

Jerry
Posted by: MDinana

Re: Compass - 10/24/10 03:25 PM

Originally Posted By: comms
dont worry about the Mayan end of the world on 12/12/12 thing. the 3 guys who came up with that deal based on a single paragraph of tablet just said that they were off by as much as 200 years.

Is it a co-incidence that they state this two years before the date and they are all still alive? you decide.

I wouldn't worry much either. If I recall my college correctly (it's been a while), the poles have shifted in the past, several times. No, not recently. But we're all still around.

Honestly I'm not well versed in it, but I can't imagine it'd have any real noticable effects. The earth's magnetic field would still be around. I mean, an MRI machine has more magnetism than your typical baseline magnetic field.
Posted by: Outdoor_Quest

Re: Compass - 10/24/10 03:55 PM

Thank you to all for the responses.

Regarding the 8010G by Brunton, I have been using mine for years. I've sold many to my students and have had positive feedback.

I'd like to see Brunton improve the red lines on the compass ring (on the face) used when triangulating a postion fix.

All the best,

Blake
www.outdoorquest.biz
Posted by: Art_in_FL

Re: Compass - 10/24/10 08:03 PM

I would avoid, or at least be careful about, selecting any compass with adjustments to correct for declination. I'm used to correcting for it in this area but anything that can be adjusted can be maladjusted, spun in the wrong direction (doubling the error) or adjusted for one area and used in another.

I like a compass to do what a compass does, point at magnetic north. I'll do my own correcting.

My preferred solution is to apply a piece of tape and write the correction factor on it as a reminder. This keeps me from forgetting the declination by forcing me to correct for it. After the first few times it becomes second nature.
Posted by: Teslinhiker

Re: Compass - 10/24/10 09:23 PM

Originally Posted By: Art_in_FL
I would avoid, or at least be careful about, selecting any compass with adjustments to correct for declination. I'm used to correcting for it in this area but anything that can be adjusted can be maladjusted, spun in the wrong direction (doubling the error) or adjusted for one area and used in another.



My Suunto M-3DL compass has an adjustment for declination and despite moderate to heavy use over the last few years, there have been no problems that you have mentioned. Like anything else, all gear whether it be a compass or a sleeping bag needs to be checked on a regular basis, regardless of it's intended use...
Posted by: KenK

Re: Compass - 10/25/10 05:45 PM

Originally Posted By: JerryFountain
The Brunton baseplate compasses are made by Silva in Sweden ...


Are you sure of that?

I suspect that the compasses that existed BEFORE Silva of Sweden acquired Suunto (the "green ones" - 8010G, 9020G, & 8040G - and the Eclipse compasses) are made somewhere else, but I honestly don't know where. I don't have one of them here at work (sorry) so I can't look on it to see if it has a "made in xxxx" label.
Posted by: KenK

Re: Compass - 10/25/10 05:49 PM

Originally Posted By: Teslinhiker
Originally Posted By: Art_in_FL
I would avoid, or at least be careful about, selecting any compass with adjustments to correct for declination. I'm used to correcting for it in this area but anything that can be adjusted can be maladjusted, spun in the wrong direction (doubling the error) or adjusted for one area and used in another.



My Suunto M-3DL compass has an adjustment for declination and despite moderate to heavy use over the last few years, there have been no problems that you have mentioned. Like anything else, all gear whether it be a compass or a sleeping bag needs to be checked on a regular basis, regardless of it's intended use...


I tend to fall in Teslinkhiker's camp there.

Stoves are special candidates for careful pre-trip testing and care. That is why I like stoves that are simple and completely field maintainable. Some of mine are getting to the age where I think seals & gaskets are aging out.

Anything that involves a battery too.
Posted by: BorkBorkBork

Re: Compass - 10/25/10 06:04 PM

Info on the Silva on Wikipedia:
http://en.wikipedia.org/wiki/Silva_compass

Silva has been acquired by Fiskars, but Silva has not yet acquired Suunto, but Suunto has aqcuired Recta though