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

"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.

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.

"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°).

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).

"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.)

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.

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.

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)

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.