Binoculars with compass
 

Hi Guys,

Sorry if my post is not in the right group, I'm not a sailor or a boatsman.

I purchased a pair of binoculars STEINER COMMANDER XP with (magnetcic)
compass via internet.
When I received de binoculars I remarked a big air bubble in the
stabilising fluid and a deviation (with respect to a (magnetic) handcompass
with optical prism) when shooting bearings.
I sent the binoculars back to Steiner for repair and after three weeks my
toy came back. The air bubble had disapeared but not the deviation.

Due north with a reference compass the STEINER indicates 002.5°
Due east with a reference compass the STEINER indicates 095.5°

A quick series of measurements (beginning north and with increments of 30°)
reveal a positive deviation with a maximum of +6.5° (from 0° to 180°) and
maximum deviation of -5° (from 180° to 360°). Drawing a graph with de
deviation values as a function of the bearing angle gives a sort of
sinusoïdal curve.

I contacted STEINER but got no reply yet.

Are there STEINER users among you with similar experiences?

Thank you for reading my post.

Jozef

Binoculars with compass
 

"Jozef" wrote in
:

Hi Guys,

Sorry if my post is not in the right group, I'm not a sailor or a
boatsman.

I purchased a pair of binoculars STEINER COMMANDER XP with (magnetcic)
compass via internet.
When I received de binoculars I remarked a big air bubble in the
stabilising fluid and a deviation (with respect to a (magnetic)
handcompass with optical prism) when shooting bearings.
I sent the binoculars back to Steiner for repair and after three weeks
my toy came back. The air bubble had disapeared but not the
deviation.

Due north with a reference compass the STEINER indicates 002.5°
Due east with a reference compass the STEINER indicates 095.5°

A quick series of measurements (beginning north and with increments of
30°) reveal a positive deviation with a maximum of +6.5° (from 0° to
180°) and maximum deviation of -5° (from 180° to 360°). Drawing a
graph with de deviation values as a function of the bearing angle
gives a sort of sinusoïdal curve.

I contacted STEINER but got no reply yet.

Are there STEINER users among you with similar experiences?

Thank you for reading my post.

Jozef




http://www.astro.uu.nl/~strous/AA/en...he-velden.html
This webpage says the magnetic declination for NL/BE is "less than 10
degrees". The pole is not at the physical rotation pole. The
declination makes every point on earth read something different. The
other variation is local variation. Magnetic outcroppings of iron ore
may put compasses in the area where the outcropping is located off by
many, many degrees.

A compass never reads N at 000 degrees, unless you happen to be on that
imaginary longitude where the declination is zero and the magnetic
variation is zero. Anyplace else on the planet, a compass will be off
by varying degrees, some as much as 10-15 degrees, either way, a
combination of declination, the magnetic flux at the moment (which
varies constantly), and the local magnetic variation caused by many
things underground. Reading that compass in Belgium in open country
isn't going to ever make it read N = 000 degrees.

http://www.springerlink.com/content/r0r40358718524n5/

"BELGIUM

3. Kcenigsfeld L.
Les Anomalies de la Variation Seculaire du Champ Magnetique
Terrestre en Belgique de 1913 a 1957.- Institut Royal Meteoro-
logique de Belgique, Publications Serie A, N13, 1963."

You will find your exact declination and local anomalies at the World
Data Center that collects it all:
http://www.geomag.bgs.ac.uk/gifs/surveydata.html
Fill in the forms to get it.......instead of buying it from the stupid
booksellers across the planet that keep the data from public viewing if
they can, so they can sell it to you.

Binoculars with compass
 

On Mar 12, 4:13 pm, "Jozef" wrote:
...
A quick series of measurements (beginning north and with increments of 30°)
reveal a positive deviation with a maximum of +6.5° (from 0° to 180°) and
maximum deviation of -5° (from 180° to 360°). Drawing a graph with de
deviation values as a function of the bearing angle gives a sort of
sinusoïdal curve. ...

You probably know this but magnetic "variation" or "declination" is
the difference between magnetic north and true north. Ideally a
magnetic compass will always point to magnetic north. However, even a
well adjusted compass will tend to have different errors on different
headings. These errors are called "deviation" and are typically
tabulated and corrected for. Because these errors are result of local
magnetic fields a compass, like yours, that doesn't have a fixed
location may have different deviation functions depending on its
surroundings. The errors you are seeing may be a result of where you
are using the binos. You could try testing them in another location
and see if they are still the same. However, my suspicion, given that
these are quality glasses and the errors are large, is that the
problem is more local yet. Magnetic objects on your body like wire
frame glasses, watches or jewelry may be contributing to the errors.
If that is the case and you can't or don't want to remove the
offending metal you could make up a deviation table and use it to
correct you readings. However, be aware that as you move about you
may well find yourself in a place where the deviation will deviate
from what are correcting for. With portable compasses there isn't
much to be done about this other than being very aware of your
surroundings.

Of course, it could be that there is a design or manufacturing error
on the glasses themselves. This seems unlikely with quality equipment
like Steiner but if different people in different places tend to see
the same deviation errors then there is a defect with the product.

-- Tom.

Binoculars with compass
 

"Roger Long" schreef in bericht
...
But, and Larry too, he said he was using a reference compass. Since he is
not a sailor, I doubt that it is a gyro compass.

Probably metal on his person. The reference compass may not be a
reference
unless it is a pretty good one. It wouldn't surprise me either for the
little compass in the binoculars to be off by that amount either.

I wonder how far away the reference compass is while he is making these
checks.

It sure is a lot easier to get a good magnetic reference, with proper
variation information, since GPS.

--
Roger Long

As Robert says I used a reference compass.

A RECTA DP10 with a prism optical system where you set the dial to N=0°.
Then you bring the compass to eye level and you take the sighting on the
object along the red line of the marking and read off the bearing (against
magnetic north).
The magnetic declination for my region (Denderleeuw - Belgium) is 0° 27'
West. Less then 0.5° (according to www.ngdc.noaa.gov/seg/).

I have an observation point in the open fields from where I can see 5
church towers with known coordinates. The coordinates of my observation
point are also known (measured with a GARMIN GPSMAP 76CSx)

You can now calculate the bearings from the observation point to the
different towers.
The results were then double checked on a topo map of my region.
Then I measured the different angles with the RECTA DP10 and the STEINER
COMMANDER (see table)

TOWER CALCULATED RECTA STEINER
----------------------------------------------------------
1 357.5° 358° 360.5°
2 89.6° 89.5° 96.5°
3 131.6° 131.5° 137.5°
4 187.2° 187° 187°
5 270.5° 271° 268°
----------------------------------------------------------

Notice that the difference between the calculated values and the RECTA
readings are within 0.5°.
The STEINER readings are to my astonishment is much further off (except for
tower 4).
To the E and SE the differences are positive and to the W negative.

Major disturbances of the magnetic field would affect both compasses I
suppose.
The readings of the RECTA are close enough to rule these out.

These measurements are done over and over and by different persons with
almost the same results (within 0.5°).

Binoculars with compass
 

Jozef wrote:
....

Major disturbances of the magnetic field would affect both compasses I
suppose.
The readings of the RECTA are close enough to rule these out.

These measurements are done over and over and by different persons with
almost the same results (within 0.5°).



It seems as though you have a good grasp of the concepts here, and it
appears that the Steiner has come up lacking. There are still a few
possibilities. I was going to mention temporary magnetic fields from
motors and speakers, but this is unlikely in a field, unless you were
using your iPod or cell phone during the Steiner test. I had a learning
experience years ago where a small portable radio sitting next to the
compass shifted our course 15 degrees.

Another possibility is that the compass is built for the southern
hemisphere, where the "dip" is different. I'm not sure if this problem
would manifest itself in this way, but its worth considering. I assume
the serial or model number can be used to track down the latitude the
compass is set for.
http://www.steiner-binoculars.com/do...mpassZones.pdf

And of course, its possible that this is a manufacturing or design flaw.
Steiner (like most companies) doesn't publish any specs for compasses,
but 7 degrees seems like a lot, especially since the field of view is
only 7 degrees.

Please let us know how this turns out. Nowadays, most sailors simply
use a GPS, but not too long ago hand bearing compasses were a primary
navigation tool, and I remember debates as to whether a dedicated
compass was better than one built into the binoculars (I favored the
former).

Binoculars with compass
 

"Roger Long" wrote in message
...
But, and Larry too, he said he was using a reference compass. Since he is
not a sailor, I doubt that it is a gyro compass.

Probably metal on his person. The reference compass may not be a
reference unless it is a pretty good one. It wouldn't surprise me either
for the little compass in the binoculars to be off by that amount either.

I wonder how far away the reference compass is while he is making these
checks.

It sure is a lot easier to get a good magnetic reference, with proper
variation information, since GPS.

--
Roger Long



I wonder if he should get an updated chart for his area.
He should be able to situitate himself at one of the 'landmarks' and use the
chart to calculate what either a true bearing or a magnetic bearing should
be to another easily reconizable landmark (re info on the compass rose).
Then he can take bearings with his handheld reference compass and the
expensive binocular compass. (after removing eyeglasses, watch, or anything
else magnetic in nature.)

Binoculars with compass
 

These measurements are done over and over and by different persons with
almost the same results (within 0.5°).

I gather the Recta is held at arms length with one hand while the
binos will, of course, be held with both hands right up to the user's
face. So, the Steiners are more likely to be subject to errors from
metal frame glasses or watches with metal components. (You don't have
a WWV receiver in you watch do you?) I'd double check to make sure
that isn't what's happening. If the Steiners are lighted you might
try taking the batteries out and see if that changes your deviation
table. If there are any other metal parts on the glasses that can be
removed (eg. strap adjusters) remove them, too.

Also, the jewel in the Steiners might be jamming. Try going to your
bearing from the right and then from the left and see if there are
differences in the errors. If you tilt the binoculars up and down
does the card break free and settle on a new bearing? If you
overshoot the bearing and move back to it does the answer change?

As another poster has mentioned there Earth's magnetic field is in
three dimensions and so most magnetic compasses come in Southern and
Northern hemisphere models. When used outside of the mid-latitudes of
their intended hemisphere they will have tilt error. My experience is
that tilt seldom changes the ultimate reading on the card but may make
the card take longer to settle. If you do have tilt error, changing
the horizontal plane of the glasses should free it up, but you should
also get new binoculars!

-- Tom.

Binoculars with compass
 

On Mar 12, 10:33 pm, "Roger Long" wrote:
But, and Larry too, he said he was using a reference compass. Since he is
not a sailor, I doubt that it is a gyro compass.

Probably metal on his person. ...

Didn't I say that? I just wanted to make sure that we all knew the
definitions of variation, declination and deviation before we got
started. Like you, I thought it was a deviation issue, though now I'm
leaning towards a bad jewel.

-- Tom.

Binoculars with compass
 

On Thu, 13 Mar 2008 12:36:19 -0700 (PDT), "
wrote:

These measurements are done over and over and by different persons with
almost the same results (within 0.5°).

I gather the Recta is held at arms length with one hand while the
binos will, of course, be held with both hands right up to the user's
face. So, the Steiners are more likely to be subject to errors from
metal frame glasses or watches with metal components. (You don't have
a WWV receiver in you watch do you?) I'd double check to make sure
that isn't what's happening. If the Steiners are lighted you might
try taking the batteries out and see if that changes your deviation
table. If there are any other metal parts on the glasses that can be
removed (eg. strap adjusters) remove them, too.

Also, the jewel in the Steiners might be jamming. Try going to your
bearing from the right and then from the left and see if there are
differences in the errors. If you tilt the binoculars up and down
does the card break free and settle on a new bearing? If you
overshoot the bearing and move back to it does the answer change?

As another poster has mentioned there Earth's magnetic field is in
three dimensions and so most magnetic compasses come in Southern and
Northern hemisphere models. When used outside of the mid-latitudes of
their intended hemisphere they will have tilt error. My experience is
that tilt seldom changes the ultimate reading on the card but may make
the card take longer to settle. If you do have tilt error, changing
the horizontal plane of the glasses should free it up, but you should
also get new binoculars!

-- Tom.


Perhaps you need to go to:
http://www.steiner-binoculars.com/bi...arine/395.html
and read up on these glasses. They have a world wide chart showing
deviation in various areas. The maximum I noticed was 12.0 degrees.

The chart seems to indicate that the compass is "balanced" for the
specific area where the glasses are sold.




Bruce-in-Bangkok
(correct email address for reply)

Binoculars with compass
 

On Mar 13, 5:39 pm, Bruce in Bangkok wrote:
... Perhaps you need to go to:http://www.steiner-binoculars.com/bi...arine/395.html
and read up on these glasses. They have a world wide chart showing
deviation in various areas. The maximum I noticed was 12.0 degrees.

The chart seems to indicate that the compass is "balanced" for the
specific area where the glasses are sold.

Good link. I don't believe that they are really talking about
deviation errors -- it's been a long hot day and beer has happened so
I could be wrong... I think they are talking just about tilt.
However, if that's true then the design is disappointing. It isn't
hard to make compasses that are much, much less affected by tilt.
I've got a couple of Plastimo Iris 50's that are Australian and I've
used them all over the Pacific with no serious problems. Tilt is
generally less than 10 degrees anywhere where the water is likely to
be liquid so, any sail boat compass will need to be designed to work
at angles much greater than those induced by magnetic tilt. I've even
seen flat compasses with an extra movement that lets the compass
magnet align itself with the Earths field in 3D. If the problem
really is tilt, and it is easy to tell by tilting the glasses up and
down, then the design is seriously flawed.

-- Tom.

Binoculars with compass
 

On Thu, 13 Mar 2008 21:09:24 -0700 (PDT), "
wrote:

On Mar 13, 5:39 pm, Bruce in Bangkok wrote:
... Perhaps you need to go to:http://www.steiner-binoculars.com/bi...arine/395.html
and read up on these glasses. They have a world wide chart showing
deviation in various areas. The maximum I noticed was 12.0 degrees.

The chart seems to indicate that the compass is "balanced" for the
specific area where the glasses are sold.

Good link. I don't believe that they are really talking about
deviation errors -- it's been a long hot day and beer has happened so
I could be wrong... I think they are talking just about tilt.
However, if that's true then the design is disappointing. It isn't
hard to make compasses that are much, much less affected by tilt.
I've got a couple of Plastimo Iris 50's that are Australian and I've
used them all over the Pacific with no serious problems. Tilt is
generally less than 10 degrees anywhere where the water is likely to
be liquid so, any sail boat compass will need to be designed to work
at angles much greater than those induced by magnetic tilt. I've even
seen flat compasses with an extra movement that lets the compass
magnet align itself with the Earths field in 3D. If the problem
really is tilt, and it is easy to tell by tilting the glasses up and
down, then the design is seriously flawed.

-- Tom.


I'm sure that you are right as the only thing that varies N or S would
be tilt. But they do show an illustration of how the needle is mounted
at angle depending where the glasses are used. In any event I think
the OP is looking for a needle in a hay stack if he wants 100%
accuracy from a compass. I used to swing aircraft compasses as part
of my job and never saw one that was 100% accurate on all headings.

I also think in real life that it doesn't make any difference. There
you are standing in a moving boat and taking a sight on two fixed
objects. You are just looking for the angle between the two objects.


Bruce-in-Bangkok
(correct email address for reply)

Binoculars with compass
 

On Fri, 14 Mar 2008 06:08:16 -0400, "Roger Long"
wrote:

"Bruce in Bangkok" wrote
I used to swing aircraft compasses as part
of my job and never saw one that was 100% accurate on all headings.

You'll like this story then. Back when I was Maintenance Officer of the
flying club we put in a new windshield and some equipment that required
reswinging the compass. The shop said I couldn't do it because I wasn't an
AP but I was welcome to take the plane out and adjust it before they did the
official checks to save time and money.

I built a sight of a board with two nails in it and taped it to the
stabilizer carefully aligned with the aircraft center line. I then spent a
couple hours dragging the plane all over the ramp turning it 180 degrees and
tweaking out half the differences just as I used to do on boats. I did this
on 20 degree headings and got it damn near perfect, way within the limits
you can read while it's jiggling around in flight. I then put the plane on
the cardinal headings and ran the engine up to full power and turned all the
electronic equipment on and off and made radio checks to be sure nothing was
upsetting it. It was perfect.

The AP then came out with a little 5 dollar compass on a stick and had me
run the engine up to full power on six headings while he sighted down the
fuselage. The compass was shaking about 5 degrees each way from the
vibration of full power with locked brakes. I took his results and did a
polar graph as you are supposed to do with the data and said, "Look there is
no way you can have a 10 degree bulge on one heading sticking out like this.
You've got to recheck or do some smoothing of the data. Compass's don't act
like this. "

The shop said, "That's the FAA way. Here's your compass card." I had to
tell the club members to just ignore the compass care which would have lead
them 10 off in some directions but I could only do it verbally because, if
someone got lost and hit a mountain of course, it would have been my fault.

That's the way so much of the world works.


I worked for a company named Southern Airways at the time and we had a
"compass Rose". Put one wheel on a mark in the middle of the circle
and drag the airplane around until the tail wheel sat on another mark
and read the compass. At the time I was a lowly AP (actually A & E)
working on the flight line so just filled out a form with the compass
readings and turned it into the office. In due time an official
Compass Deviation Card was issued that we stuck in a little clip on
the instrument panel.

I used to listen to the instructors briefing the cadets for their
cross countries and I honestly think they could have flown them
without a magnetic compass as I used to hear the Instructors talk a
lot about the various railroad tracks in the area.


Bruce-in-Bangkok
(correct email address for reply)

Binoculars with compass
 

On Fri, 14 Mar 2008 15:58:49 +0700, Bruce in Bangkok
wrote:

snip

In any event I think
the OP is looking for a needle in a hay stack if he wants 100%
accuracy from a compass

snip


It doesn't seem he's looking for 100% accuracy at all. The issue here
is whether we should be surprised at the Steiner's demonstrated
errors. There is a tendency to be appalled at the performance of such
a high quality instrument. But do our prior expectations come from
some source other than the high price?

Chuck

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Binoculars with compass
 

On Mar 13, 10:58 pm, Bruce in Bangkok wrote:
I also think in real life that it doesn't make any difference. There
you are standing in a moving boat and taking a sight on two fixed
objects. You are just looking for the angle between the two objects.

I don't know how the OP intends to use the compass but 7 degrees is a
lot of error. More than twice what I'd expect from a well corrected
compass. Keep in mind, with deviation, the error will be between
headings so the angle between your two objects could be 7 degrees off
in this case... Good thing he's got a GPS.

-- Tom.

Binoculars with compass
 

On Mar 14, 8:16 am, " wrote:
... Keep in mind, with deviation, the error will be between
headings so the angle between your two objects could be 7 degrees off
in this case... Good thing he's got a GPS. ...

And, while I'm in the bad habit of replying to myself and just for the
record: you can't get a fix with just the angle between two objects
and no azimuth. The angle only gives you a circle of position (or to
be fully correct two possible circular arcs of position except where
you have a transit and it becomes a line of position). With just
angles between objects you need three to get a 2d fix (unless you have
transits where you only need two). But you knew that :)

-- Tom.

Binoculars with compass
 

On Thu, 13 Mar 2008 08:53:53 -0400, jeff wrote:

I had a learning
experience years ago where a small portable radio sitting next to the
compass shifted our course 15 degrees.

Could I point out the that speakers always have a magnet. About the
worst thing I can think of to put near a compass

Casady

Binoculars with compass
 

On Fri, 14 Mar 2008 11:16:58 -0700 (PDT), "
wrote:

On Mar 13, 10:58 pm, Bruce in Bangkok wrote:
I also think in real life that it doesn't make any difference. There
you are standing in a moving boat and taking a sight on two fixed
objects. You are just looking for the angle between the two objects.

I don't know how the OP intends to use the compass but 7 degrees is a
lot of error. More than twice what I'd expect from a well corrected
compass. Keep in mind, with deviation, the error will be between
headings so the angle between your two objects could be 7 degrees off
in this case... Good thing he's got a GPS.

-- Tom.

I had assumed that he was using the glasses to measure the angle
between two known objects as is normal with a hand bearing compass. In
which case whether or not the glasses were reading the correct
magnetic heading is irrelevant.

Bruce-in-Bangkok
(correct email address for reply)

Binoculars with compass
 

Richard Casady wrote:
On Thu, 13 Mar 2008 08:53:53 -0400, jeff wrote:

I had a learning
experience years ago where a small portable radio sitting next to the
compass shifted our course 15 degrees.

Could I point out the that speakers always have a magnet. About the
worst thing I can think of to put near a compass

Casady

No

Binoculars with compass
 

On Fri, 14 Mar 2008 11:42:16 -0700 (PDT), "
wrote:

On Mar 14, 8:16 am, " wrote:
... Keep in mind, with deviation, the error will be between
headings so the angle between your two objects could be 7 degrees off
in this case... Good thing he's got a GPS. ...

And, while I'm in the bad habit of replying to myself and just for the
record: you can't get a fix with just the angle between two objects
and no azimuth. The angle only gives you a circle of position (or to
be fully correct two possible circular arcs of position except where
you have a transit and it becomes a line of position). With just
angles between objects you need three to get a 2d fix (unless you have
transits where you only need two). But you knew that :)

-- Tom.
Well, normally when you are doing it you take the angle between two
points a known distance apart...

Bruce-in-Bangkok
(correct email address for reply)

Binoculars with compass
 

On Mar 14, 4:41 pm, Bruce in Bangkok wrote:
... I had assumed that he was using the glasses to measure the angle
between two known objects as is normal with a hand bearing compass. In
which case whether or not the glasses were reading the correct
magnetic heading is irrelevant.

I don't understand what you are saying. Bearing compasses are almost
always used to get azimuths which are then often plotted on a chart.
They have to read properly to work. If you just want to know the
angle between two objects you don't need a compass at all. For small
angles you can get within a few degrees just siting over you
outstretched hand (each knuckle is about 3 degrees). A cross staff,
peloris, kamal, sextant etc can be used for larger angles. If the
magnetic heading is irrelevant why have a magnet compass at all?

-- Tom.

Binoculars with compass
 

On Mar 14, 4:48 pm, Bruce in Bangkok wrote:
Well, normally when you are doing it you take the angle between two
points a known distance apart...

That still gives you an arc of position, not a fix.

-- Tom.

Binoculars with compass
 

Bruce in Bangkok wrote:
On Fri, 14 Mar 2008 11:16:58 -0700 (PDT), "
wrote:
I don't know how the OP intends to use the compass but 7 degrees is a
lot of error. More than twice what I'd expect from a well corrected
compass. Keep in mind, with deviation, the error will be between
headings so the angle between your two objects could be 7 degrees off
in this case... Good thing he's got a GPS.

I had assumed that he was using the glasses to measure the angle
between two known objects as is normal with a hand bearing compass. In
which case whether or not the glasses were reading the correct
magnetic heading is irrelevant.

This is only true if the error is constant. For example, you don't have
to be concerned with variation if you're only considering the angle
between two objects. However, if, as is apparently the OP's case, the
compass has deviation that changes with heading, then the computed angle
will be faulty. The reported data implies that the angle could be off
by more than 8 degrees, which makes it hardly worth plotting.

Traditionally, a horizontal sextant sight is taken. This can give a
high degree of accuracy. Until recently, such sights were the primary
technique for positioning buoys.

Binoculars with compass
 

On Mar 15, 3:52 am, jeff wrote:
... between two objects. ...
Traditionally, a horizontal sextant sight is taken. This can give a
high degree of accuracy. Until recently, such sights were the primary
technique for positioning buoys.

That's not less than three, (3), (...---), (2+1), etc. objects for
horizontal angles not in transit to get a fix. :) That's why they
have three armed protractors.

-- Tom.

Binoculars with compass
 

On Sat, 15 Mar 2008 09:41:57 +0700, Bruce in Bangkok
wrote:

I had assumed that he was using the glasses to measure the angle
between two known objects as is normal with a hand bearing compass. In
which case whether or not the glasses were reading the correct
magnetic heading is irrelevant.
\
GPS is here to stay, but the sextant has other uses. Measuring the
vertical angle subtended by something, a lighthouse perhaps, of known
size, will give the range.

Casady