I was recently searching for a new compass as my old Silva 3nl needle capsule looks like an aquairium with delaminated paint particles and is going brown with I presume rust. I have always wanted a sighting compass which could be used with a map, so must have a transparent base plate. So first choice was the Silva 15TDCL, then I looked at Suunto who have something similar, then I noticed Brunton who look like Silvas and Recta whose products look like Suuntos, in fact the only difference is the brand name on the baseplate. So I assume Silva make compasses for other names and Suunto similarly or at least they sell their designs to others. Anyway, it seems to me out of these four makers names, a similar product can be had for much the same price.
But for the fun of it, I bought an ASA compass, also called the C102, which is a copy of the Silva/Brunton Ranger Expedition compass, the 15TDCL. It is quite frankly pretty good, the only negative I have for it, is that it does not have a fluid filled capsule to damp the needle otherwise, it is much the same as the Silva/Brunton. These compasses are generally aimed at Earth Sciences students who require the function, but may baulk at the price of a suitable instrument, these being £14.99 including p+p on ebay, a buy it now item.
The magnetic declineation screw works well, with the brass screwdriver provided, the sighting system works as does the clinometer and in comparison to my old 3nl, sighted in the best way I can bearing in mind it is not a sighting compass, the ASA is accurate, but one has to hold the compass level for it to find north. I will soon try it in the field and see how it goes.
I have a TDCL compass and it is very good indeed. To be honest though, I got it over any other model similar available there and then, as it has three of my first name initials in its title more than for any other reason, I being a Trevor David Charles!
TDC of course in mechanics stands for 'Top Dead Centre', which was therefore - due to my same name initials - a nickname one of my best and oldest friends called me, as he was himself a former RN engineer. One of my beter nicknames given to me by friends in the past that one was!
Prismatic type sights are lighter, easier to use and more accurate than sighting mirrors. They are, of course, more expensice too, but the Silva 54 NL is about as good as it gets if you want a protractor compass to do sighting as well.
TBH, I don't find I use the sighting function very much, but at least it's not adding much to weight and bulk and is still there if I need it.
Tip for using mirror sighting is ignore the usual instructions of holding the compass up in front of you and reading off angles in the mirror. Instead, hold the compass down in front of your belly with the mirrir towards you and open at 135 degrees. Sight in the mirror, and read the bearing directly: much easier! (got that from a BGS booklet on doing geological mapping fieldwork when I was an undergrad).
> Tip for using mirror sighting is ignore the usual instructions of holding the compass up in front of you and reading off angles in the mirror.
Or don't both to try to read the angle in the mirror; just use the mirror to sight and set the compass, and then read it conventionally...
I can see that if you're surveying, you might want to take multiple sightings in one spot, but it's unusual for navigation (unless you're doing a re-section, in which case you probably transfer the bearing to the map using the baseplate, rather than taking a real reading).
> Instead, hold the compass down in front of your belly with the mirrir towards you and open at 135 degrees. Sight in the mirror
This means you have to reverse the usual 'North' direction on the baseplate. Not a real problem, as long as you're aware of this...
To clarify the situation on similar compasses from different "manufacturers":
Silva do not own the brand name Silva in North America so sell under the Brunton and Nexus brands, if you look at the manuals on the Brunton website you'll see these refer to them being made in Sweden for Brunton and the manuals are branded as Nexus. Brunton, Silva and Gerber are all owned by Fiskars.
Suunto bought Recta in 1996, both are now owned by Amer Sport.
The K+R compasses, I have seen those, Blacks appear to sell them, but a mirror compass has so many uses like heliograph, shaving mirror, make up mirror for youse that like to wear that stuff, but more likely making sure your face is not covered in soot from a dirty stove.
I have to carry a mirror for overnighters because I can't get my contact lenses in without one. Never thought of buying a sighting compass with one to save on kit.
Yep, an excellent reason to get a mirror compass and you already have a use for it aside from getting lost. I have just got my hands on A Suunto MC-2/360/D, mirror compass, the equivalent of the Silva 15 TDCL, so a pretty good compass and all for ten quid of ebay incl postage. Suunto are at least Finnish and good on innovation too. As I want to in a while travel in North Africa, at least this compass is balanced for use in that area, Zone 1
