A Low-Key Guide to Feng Shui (1): How to Choose a High-Precision Compass That Can Replace an Ordinary Feng Shui Luopan

First published on the WeChat official account "Daoist Yinfu Culture," 2019-08-06. Illustrations omitted.

1. Why not use a feng shui luopan

Last time this poor priest's party was in Sydney, Australia. Passing a church, they were quite curious, so the whole group headed for the church entrance carrying a luopan.

Obviously, they were chased off at the door—people at the church entrance were shouting, not even willing to let us set foot on the steps before the door.

This was in Australia; had it been an Arab country, ahem...

2. Why high precision is required

When the feng shui luopan cannot be used, how can one obtain sufficiently precise feng shui data? That becomes the question.

Why insist on precision?

Imagine a mountain peak that falls exactly on the seam between two sitting mountains on a traditional luopan. With a two-degree error, it is hard to judge whether it truly lands here or leans toward which sitting mountain.

If even whether it falls on the seam is hard to confirm, how can one proceed to further judgments?

Even so, some people still say that actual feng shui measurements need not be that precise—whether using the Twenty-Four Mountains or the square-and-round sixty-four trigrams, one can determine things without excessive accuracy.

Although most of the time strict precision is not required, under special conditions it still matters. For example, the true needle of the luopan: as this poor priest uses it, only within 1.5 degrees on either side of the true position counts as the true needle; once the left or right deviation exceeds 1.5 degrees and enters the remaining six-degree range, it is uniformly treated as a "leaning" reading.

For instance, the San Yuan never-failing configuration Master Lai once made for the Li Clan Ancestral Hall in Dongguan: three gates, each not precisely facing straight, but each pair differing by only one degree. Achieving this in construction necessarily required accurate measurement.

Of course there is also a school of feng shui called the muddled school: they hold that whether there is interference or whether the luopan has problems, whatever data measure out is the data—and one may determine the feng shui from that.

The idea of this school is simple: the ancients did not have such precise surveying techniques; at least in Master Yang's time—that is, the Tang dynasty—things were very crude.

This is pure armchair fancy: far too dismissive of the astronomical and surveying techniques of ancient China.

Take records in the Hou Hanshu, for example: "In the first month of the second year of Jianwu of Emperor Guangwu, on a Jiazi new moon, there was a solar eclipse, at eight degrees of the Encampment mansion." It is clear that Han-era records already reached specific mansions and specific degrees.

And the Twenty-Eight Mansions divide the celestial circuit into three hundred sixty-five degrees—slightly more precise than the commonly used three-hundred-sixty-degree circuit of today. If the surveying techniques of the time had not reached that level, how could such records exist?

Although there is currently no clear evidence of very high-precision luopans before the Song, the ancients did not need a luopan for observation angles—they needed only to observe the stars.

Even in modern times, calibrating a luopan and computing true north still used star observation. Of course, now that north-seeking instruments have been invented, one can point precisely to true north and correct without astronomy.

3. Basic requirements for choosing a north-pointing compass

For professional surveyors, simply using a theodolite is of course easiest—but clearly, what is usually needed is a precise yet portable compass device.

When a feng shui luopan cannot be used, one should consider a compass with sufficient precision. What kind of compass device precision can meet our needs?

1. The luopan/compass must be able to lock the needle. If it cannot lock the needle, long journeys or the jolting of an airplane may damage the needle bearing and reduce measurement accuracy.

2. The luopan must be able to sight distant objects: it must have a sighting line or notch for aligning with the tops of distant peaks, or for measuring the coming and going of water mouths.

3. Ideally the luopan should minimize errors caused by tilt angle, avoiding mistakes from improper leveling.

First, electronic compasses are rejected outright. Most ordinary electronic compass chips, once spun a few turns in place, immediately lose their bearing; anti-interference ability is also extremely poor. This is a problem inherent to the gyroscope itself.

Even those multi-thousand-yuan electronic compasses claiming zero-point-something precision themselves require the user to avoid rotating during use, or accuracy will suffer.

Solving this requires a north-seeking instrument—but such devices are both bulky and complex to operate, unsuitable for portable use. So electronic compasses may essentially be treated as without foundation: one must use mechanical ones.

Second, some online shops sell compass devices imitating the U.S. military Romen compass; wholesale prices are generally a few tens of yuan. Their product descriptions claim errors within plus or minus one degree—which looks good. But is this usable?

First note: within plus or minus one degree actually means precision under two degrees. Obviously this cannot meet our needs.

4. Various types of north-pointing compasses

1. Suunto compasses

Finland's SUUNTO company has been dedicated to precision outdoor equipment since the 1930s, offering stable and accurate liquid-filled compasses. Yet even for such a company, the accuracy of its flagship matchbox-style compass is 2.5 degrees.

Conclusion: does not meet feng shui requirements.

2. Cheap domestic brand compasses

Although domestic capability is believed to be strong enough, because prices are so low it is fair to wonder whether makers truly care enough to achieve this accuracy; so whether the data are exaggerated is hard to determine.

So this poor priest also looked through some international market reviews, which say like this:

If you want an accurate compass that helps you navigate precisely, this is not for you. Like others, the dial is not centered, and the night illumination is not that good. In my case, if I put the north indicator on the north arrow, the south indicator is off by 3 degrees. Over a long distance this will be a real problem.

This compass feels much heavier than the standard army issue. When I hike, weight becomes an issue, and I would not carry this as a backup. I still give it four stars, because for land navigation or other applications it seems fine.

Others are not listed one by one; roughly five percent of reviews were not ideal. But objectively, this domestic compass still received seventy-four percent favorable ratings—so whether it can truly meet our use requirements needs further verification.

Conclusion: for now open to doubt; needs further verification.

3. U.S. military compass

The compass used by the U.S. military has dedicated standards, following the MIL-PRF-10436 specification. In this specification, the requirement is that error must not exceed 40 mils.

A mil is the arc length of a circle divided into a certain number of equal parts. Europe and America typically divide one circle into 6400 mils, while Russia uses 6000 mils.

The compass circle is 6400 mils—that is, 360 degrees. Calculation shows the required error cannot exceed 0.8 degrees.

It achieves relatively high precision in such a small body chiefly thanks to the magnifying glass designed into the cover plate: the magnifier enlarges the angle, enabling more precise reading.

Worth noting: this U.S. military compass is made of cast aluminum, very light, uses sapphire bearings, and can be used in extreme weather; dustproof, sandproof, waterproof, and rugged durability go without saying. When closed it can lock the needle—it is a usable product.

But it also has an obvious problem: the angles shown on the two rings of scales are not the celestial-circuit degrees we need from direct measurement; conversion is still required, which is rather troublesome.

Special reminder: domestically there are large numbers of imitated U.S.-style compasses. The cheap ones usually use plastic shells, selling for a few tens of yuan each, with wholesale prices actually under ten yuan.

The compass actually used by the U.S. military: the M-1950 3H field compass (MIL-PRF-10436N) civilian version on Amazon is about $86.70, roughly 600 yuan RMB, manufactured by Cammenga—a company that began making compasses in 1992 and mainly manufactures the 3H-type for the U.S. military.

Conclusion: meets feng shui requirements.

4. Chinese Type-97 compass

The compass used by the Chinese military has gone through several changes. The Type-62 has a long needle-stabilization time; the Type-80 had some quality problems—oil leaks, unreliable needles; the current newest is the Type-97, combining Type-62 and Type-80 features, with precision within plus or minus one degree.

From the figure one can see: without a magnifying glass, identifying the needle is somewhat difficult when examined carefully.

But its materials are high-strength aluminum alloy; other materials are almost all the best available. It is relatively light; the mirror reading is convenient; slope measurement is easy; and its design mainly pairs with military maps.

This precision in fact cannot meet our needs. Wholesale price is usually between 150 and 200 yuan; authenticity unknown. There is also the Type-97 made by Haguang, also within plus or minus one degree—so it does not fully meet our needs.

Conclusion: does not meet feng shui requirements.

6. Cheap imitations of U.S. military tactical compasses

On Taobao there is something called a U.S. military tactical compass, with an integrated eyepiece, very cool-looking—but they are all toy grade, because they do not even annotate error margins.

Conclusion: does not meet feng shui requirements.

7. Haguang geological compasses

All things considered, the U.S. military compass is relatively usable. But if it is hard to buy, one needs to consider the more common geological compass long tested by the industry.

Among domestic geological compasses, the first recommendation is of course the geological compass made by Haguang. Ordinary models cost about two or three hundred yuan each, with precision reaching 0.5 degrees—meeting use requirements.

Other domestic brands also offer corresponding compasses, but their shells do not use metal; although they also claim 0.5-degree precision, anti-interference ability is very weak; they cost a few tens of yuan each and are unusable.

8. Other feng shui luopans from Haguang

By the way, Haguang has also released several feng shui luopans. Who designed them is unclear—toy-like, and the product descriptions simply omit any mention of precision.

For example, a hanging-type luopan is basically unusable except as an ornament. Another geological compass has the Twenty-Four Mountains added below but is neither anti-magnetic nor waterproof nor iron-proof—also basically an ornament.

What does have some professional value is their theodolite with telescope, whose face uses the Twenty-Four Mountains. But as said at the start, theodolites are simply too bulky and inconvenient to carry.

Another somewhat noteworthy product is Haguang's pocket feng shui luopan. Of course the product description is again a mess—positioning them as gift-grade, so the actual precision is doubtful.

But one point can be confirmed: reading angles by the needle, without a magnifying eyepiece, the precision can at best be taken as two degrees.

Conclusion: visual precision insufficient; cannot meet actual use needs.

8. Suunto KB-14

Why call it a divine tool? Although portable, it can reach one-quarter-degree precision; in actual use, errors within half a degree are generally no problem—so this poor priest also often uses this.

That is Finland's Suunto KB-14. Its method of use is peculiar: you look with only one eye, keeping the other eye open, and the brain automatically fuses the target image.

But this divine tool also has a major flaw: if you have latent strabismus, you usually cannot obtain ideal measurement results.

Domestically on Taobao the price is listed above two thousand; overseas purchase actually costs only a thousand-some yuan RMB including tariffs.

Conclusion: usable, but the method of use is not suitable for everyone.

9. Suunto Tandem

An enhanced version of the KB-14; can be used to measure heights, slopes, and so on.

Conclusion: usable, but the method of use is not suitable for everyone.

10. Brunton Omni-Sight Sighting Compass

Usage is similar to the KB-14, but it carries more data. Official site price is $169.99, though other sites sell it for $139 or lower; it seems somewhat better than Suunto's KB-14.

Conclusion: usable, but the method of use is not suitable for everyone.

11. Brunton Comp-Pro Pocket Transit

Actually it is a geological compass—but even the cheapest model on the official site costs as much as $334.99. Honestly, buying a domestic one is still better.

Conclusion: usable.

5. Conclusion

Domestic or foreign geological compasses, Suunto KB-14, Suunto Tandem, Brunton Omni-Sight Sighting Compass, the U.S. military M-1950 3H field compass, and the like—these can all meet use needs.

Counting carefully, among them the most practical this poor priest finds is the U.S. military M-1950 3H field compass. The reason is simple: its dial has mils, and 6400 mils correspond exactly to the sixty-four trigrams.

Because the mils on the compass start from zero degrees, and the traditional feng shui luopan also starts from zero degrees at the Kun trigram, it is easy to convert to the sixty-four-trigram square-and-round plates. It also has celestial-circuit angles, so simply dividing by fifteen easily converts it to the Twenty-Four Mountains.

In fact, the M-1950 3H field compass is not necessarily superior in technology to other top-tier compasses; its key advantage is the cleverly designed magnifying glass, which greatly raises the precision of reading compass data.

If other compasses could add such a magnifying eyepiece, the needle could certainly be made thinner or sharper—and precision would rise dramatically.