HDTenEightyP/NetNews huggingface dataset:
From: srobiner@pollux.usc.edu (Steven Robiner)
Newsgroups: sci.space,sci.astro
Subject: Answers to PLANES of the ecliptic question
Date: 21 Jul 1992 16:35:44 -0700
Organization: University of Southern California, Los Angeles, CA
Distribution: world
NNTP-Posting-Host: pollux.usc.edu

Thanks to all who responded to my question about the solar
system's plane of ecliptic relative to the galaxies. Almost
everyone who responded agreed that the number was about
60 degress.  The rest of the details were most consisely
summed up by the following to respondents.

Thanks agian to all who responded.

=steve=

----------------
From: Hartmut Frommert
	Dept. of Physics, University of Constance

The galactic North Pole is at 
 
L=0.018      B=-29.81   degrees in Solar System Main Plain coord's.

[ calculated from
   Solar System North P: R.A.= 18 h 00 m = 270.00 deg, Dec = + 66.55 deg
   Galactic North Pole:  R.A.=  0 h 49 m =  12.25 deg, Dec = - 27.40 deg ]

This implies an *inclination* of

i_g = 119.81 degrees

(and a node Omega_g = 90.018 degrees). So the inclination of both axes/
equators is approx. 60 degree, the direction of rotation is opposite.

Changes are due to 
 - galactic rotation (order of 200 million years, 0.2 arc secs per century)
   This changes mainly only the node line. Only the inclination of solar 
   system's orbit around the galactic center changes *i_g* (periodically).
 - angular momentum transfer to other stars/clusters/the Galaxy
   which I assume you can forget.

-----------
From: Bill Gawne, Space Telescope Science Institute

The galactic north pole (J1950 coordinates) is at 
right ascention 12 h 49 m, declination 27 degrees 4 minutes.
So the galactic equator is a plane going thru the galactic center
in Sag A perpendicular to this direction.  It is outlined in
star atlases such as Wil Tirion's Sky Atlas 2000.0

Roughly, its a 63 degree tilt.  Yes, this changes as the sun orbits
the galactic center.  The solar motion is not simply circular, it also
moves up and down thru the disk of the galaxy.  Look at an introductory
astronomy book for the period of the sun's orbit about the GC.
From: chennankb@woods.ulowell.edu
Subject: HELP REGISTER Waveguide holography researchers
Organization: University of Lowell
Date: Fri, 24 Jul 1992 20:32:00 GMT

I have recently come across a renewed interest in waveguide holography.

But I have not yet found much literature on it.  Is there anyone who
 
could provide some information here.



berty john chennankara 

Newsgroups: sci.optics
From: doug@shako.Colorado.EDU (Doug McKnight)
Subject: Re: Looking under water with your eyes open
Reply-To: doug@shako.Colorado.EDU (Doug McKnight)
Organization: University of Colorado, Boulder
Date: Mon, 27 Jul 1992 23:25:25 GMT

I seem to recall being told (pretty vague) that very young children 
can accomodate enough to see well under water. 

Confirm/Deny ????

Douglas McKnight. (3 Diopters short sighted)
From: IFF118@DJUKFA11.BITNET
Newsgroups: sci.optics
Subject: Re: HELP wiith BINOCULARS....!!!!
Date: 30 Jul 92 14:45:24 GMT
Organization: KFA  Forschungszentrum Juelich

I have another question,

that all geometrical factors do not show how good
is your binocular manufactered. I assume that for
instance proper coatings on all lenses ( I've been
told, that cheep devices has only outer lenses
coated, claiming all of them are - what you can
not see) and prisms can give you better preformance
with the same lens diameter.
Only once, in specs of Fujinon binoculars I've seen
a number called relative brightnees or so, which
I believe was about 0.90, and which I do not understand.

Do you know anything about it ?

Regards,
         Piotr
Newsgroups: sci.optics
From: vls@cube.handheld.com (Vern Stant)
Subject: Source for Image Intensifier Wanted
Organization: Hand Held Products, Inc.
Date: Wed, 22 Jul 1992 21:35:50 GMT

I am looking for manufacturers of image intensifiers and
ambient IR sensing/viewing devices.
Thanks,
Vern

--
Vern Stant              | The opinions expressed herein are
Hand Held Products, Inc.| not necessarily those of Hand 
804.784.3090 voice      | Held Products, Inc., and may not 
804.784.3147 FAX        | even be mine. Use at your own risk
Newsgroups: sci.optics
From: shin-jungshik@CS.YALE.EDU (Jungshik Shin)
Subject: Where to get PSD(Pos. Sensitive Device)?
Keywords: PSD,Postion,Sensitive,Foreign,Korea
Organization: Yale University
Date: Wed, 29 Jul 1992 17:47:49 GMT


 I read an article asking about PSD(Position Sensitive Device) on a BBS in
Korea.  He(poster of that article) wants to know where to get PSD. According
to him, PSD is not produced in Korea. Hence, I would be very much obliged to
you if you can give me any information on where to contact to get PSD.
Especially I'd like to know a company producing PSD  with a dealer in Korea
or other country in East Asia.  If there's no company with a dealer in Korea,
please just let me know a list of companies making PSD and their contact
points. I think Newport and other optics company make it.  But,I'm not sure.  
  You can send me mail to jshin@minerva.cis.yale.edu.

   Thanks in advance.   

   Jungshik Shin
From: dknren01@uctvax.uct.ac.za
Newsgroups: sci.optics
Subject: Re: Help with Binoculars
Summary: binoculars for astronomical applications
Date: 24 Jul 92 11:43:27 GMT
Organization: University of Cape Town

Are you perhaps looking for binoculars to use for astronomical observation?
If so, the wheel-focusing variety is much more accurate. See if you can get a
pair that has an individually focusing right eyepiece. With this type, you
first cover the right lens and focus using the cental wheel. Then you cover the
left lens instead and adjust the focus using the separate eyepiece focuser.
That way you get a perfectly focused image through both eyes, even if your eyes
are slightly unequal (as most people's are).
For astronomical viewing, the larger the main front lenses are, the better,
though of course they get heavier as they increase in size. I have a pair of
20x50s, but they are far too heavy to use without a tripod. 10x50s are about
ideal, though 10x60s are even better. I know some 10x80s exist (I think
Celestron makes them) but these are completely useless for anything other than
astronomy and their sheer bulk make a tripod absolutely necessary. I wouldn't
suggest that you try them unless you are actually looking for a piece of
specialized astronomical equipment.

Francis Bryan
c/o dknren01@uctvax.uct.ac.za
From: wlamonac@vivaldi.helios.nd.edu (william lamonaca)
Newsgroups: sci.optics
Subject: Index of Refraction
Date: 29 Jul 92 17:22:32 GMT
Organization: University of Notre Dame, Notre Dame

I'm trying to measure the index of refraction of some prisms and glass slides.

The only data I have to go by are the power of the refleected beam and the
angle of incidence of the laser beam for several different angles.  The light
is parallel polarized.  I should be able to solve for the index of refraction
by using Fresnel's equations, but my results are not very good.  Can anyone
suggest a scheme to get the indexes?
Newsgroups: sci.optics
From: doug@shako.Colorado.EDU (Doug McKnight)
Subject: Re: Looking under water ...+ Microlenses
Reply-To: doug@shako.Colorado.EDU (Doug McKnight)
Organization: University of Colorado, Boulder
Date: Tue, 28 Jul 1992 15:55:46 GMT

Of course, it's ridiculous when you generate the numbers. 

BTW Does anyone know who is making the best microlenses currently and
are the commercially available.

Douglas
Newsgroups: sci.optics
From: owen@astro.washington.edu (Russell Owen)
Subject: good stable white light source?
Followup-To: sci.optics
Organization: University of Washington
Distribution: na
Date: Wed, 29 Jul 1992 22:40:34 GMT

Can anybody recommend a good broad-spectrum (400-900 nm) light source of at
least 50W? I want it to be very stable (approx. 0.1% fluctuation in
intensity) over a period of hours (but not over the life of the bulb).It
will illuminate a 300um diameter multimode optical fiber, if that makes any
difference.

We presently use a quartz-halogen (QH) bulb driven by a constant-voltage
supply, but the light intensity varies about 1% over time. I'm not sure if
this is due to a poor power supply, air currents on the bulb, or what.

I have found several possibilities, so far, but of these I'm not sure any
but the Newport lamp will really do the job:
- Newport sells a photofeedback-stabilitized 50W QH lamp for $3800. It's
rated to be stable to within 0.1%.
- Optronic Laboratories, Inc sells power supplies for radiometric
calibration sources. These are well regulated (+/- 0.05%) constant-current
supplies. A 6.5A supply costs $3200. This will probably be fine for us but
I'm surprised it's acceptable for long-term radiometric reference sources,
since they have no photofeedback.
- Use a high-power constant-current/constant-voltage bench supply, probably
in constant-current mode. "Topward" has a decent-looking model for $700
(0-30V, 0-10A).

Let me know if you have any recommendations. If there's sufficient
interest, I'll post a summary.

Russell Owen
owen@astro.washington.edu

P.S. the sources I mentioned:
- Newport 714-963-9811 (CA). Lamp is model 780.
- Optronic Laboraties,inc. 407-422-3171 (FL). Supply is model OL 65DS.
- Topward bench supply 23010. Available from Allied Electronics
1-800-433-5700 (Allied part #668-3010), and presumably from other major
electronics distributors.
From: rknowles@garnet.berkeley.edu ()
Newsgroups: sci.optics
Subject: Re: Cheap monochromatic light?
Date: 29 Jul 1992 04:07:32 GMT
Organization: University of California, Berkeley
NNTP-Posting-Host: garnet.berkeley.edu
Keywords: monochromatic cheap no-flicker

In article <710@capmkt.COM> charles@capmkt.COM (Charles Neveu) writes:
>Optical novice question:
>I need an inexpensive monochromatic or nearly-monochromatic light
>source for visual psychophysics experiments. It should be continuous
>and not flicker. Can I do this with an incandescent light and filters
>of some sort? 

How "monochromatic"?  .1 nanometer or 10 nanometers wide?  How many
different wavelengths?  Are you going to modulate the light?  Interference 
filters are frequently used for monochromatic light.   If you can tolerate 
broad peaks, Red LEDs I think are 20 nanometers at the half-width of the peak.
Shorter wavelength LEDs are broader.

A monochromator will give you a tunable, monochromatic source but it needs a
lot of light on the input.   A laser is very monochromatic if you can tolerate
speckle.   With the exception of a laser, a very monochromatic source will have
very little luminous flux.

>
>Related question: How can make a light source that contains just the
>ends of the visual spectrum, i.e. just red and blue-violet?

Cobalt glass has this characteristic.  It used to be used in a technique
to measure the longitudinal chromatic aberration of the eye.

>Thanks, 
>
>Charles Neveu     neveu@pupil.berkeley.edu
>Neurology Unit
>U.C. Berkeley
From: charles@capmkt.COM (Charles Neveu)
Newsgroups: sci.optics
Subject: Re: Looking under water with your eyes open
Date: 27 Jul 92 19:53:11 GMT
Organization: Capital Market Technology

ulrich@tpki.toppoint.de (Ulrich Gall) writes:


>When you look under water with your eyes open, it looks blurry
>of course.

>But what if you are VERY short-sighted?

>Did anyone ever calculate this all the way through? Or try it?

Quick back of the envelope calculation:
The total amount of refraction by the eye is roughly 60 diopters, of which 
about 45 diopters is provided by the first surface of the cornea,
which is neutralized in water, and about 15 provided by the lens. You
would have to be VEEERY short-sighted. 

Charles Neveu
neveu@pupil.berkeley.edu
Newsgroups: sci.optics
From: donsilva@solomon.technet.sg (Don Silva)
Subject: Re: HELP wiith BINOCULARS....!!!!
Organization: National University of Singapore
Date: Wed, 22 Jul 1992 05:31:17 GMT

Sorry to add a bit to this, but our group is getting real thin on responses
and questions.  

Harry gave you the correct scoop.  You might consider the bulk of the
instrument also.  The bigger the objective the HEAVIER it is.  So you pay the
penalty of gathering dimmer images by needing bigger muscles.  Also the exit
pupil is important for seeing in dim light.  Your eye will dilate to around 8
mm.  So for night viewing the exit pupil should be around this size.

I would consider a compact 9 X 20 m/m for general use.  It's small and can be
worn on your belt.  I owned one of those monster -- see in the dark -- types
but never left home with them.  Now i have a compact one that i keep in the
glove compartment of the car.  

The other thing about field of view is that the larger field of view is easier
to find things.  The compact i mentioned abouve has a narrow field of view,
sometimes specified in degrees.  It takes a great deal of practice to find
what youre looking for.  Suppose you hear a bird in the tree.  Good luck with
the compact, until you get a little skill.

don
-- 
********************************************************
Don Silva (Phd)


Newsgroups: sci.optics,sci.image.processing
From: schaefer@young.ece.cmu.edu (Roland Schaefer)
Subject: Air Force Resolution Chart Question
Organization: Electrical and Computer Engineering, Carnegie Mellon
Date: Thu, 23 Jul 1992 19:04:02 GMT


I'm looking for some chart or data that will describe what
the various spatial frequencies on the AF Resolution Chart
are.  The chart just has various bars in groupings - I have
no data on what these groupings represent.

Any help would be greatly appreciated.

Thanks

Roly.


Newsgroups: sci.optics
From: ohrd!jlevine@cs.toronto.edu (Jody Levine)
Subject: Cleavers (was: Using fibers for Photoluminescence experiment)
Organization: Ontario Hydro - Research Division
Date: Wed, 29 Jul 92 21:25:42 GMT

In article <1992Jul15.224403.20168@news.larc.nasa.gov> claudio@nmsb.larc.nasa.gov (Claudio Egalon) writes:
>I have the answer just to the second question. 
>Three are three different cleavers that you  can use to cleave the end 
>of your fiber. The cheapest one is a hand cleaver. There are two other 

We call these 'potato peelers' and they look like a precision screwdriver
but instead of a screwdriver tip, there are a few milimeters or roughness
at the end to scratch the fibre before you flick off the end with your finger. 
With lots of practise one can make great cleaves and waste very little 
fibre. Getting the practise is frustrating and fibre-wasting, however.

>ones one made by Newport Corporation (may be there are other 
>companies that make this kind of cleaver) which is the second 

never tried these

>cheapest and a third one that may cost you around US$3000,00. The 
>one that we have here in our lab is made by Fujitisu. After cleaving 

These look like a mini stapler with tongue. You strip about 2 inches of
fibre (a pain), feed the stripped bit along the tongue to the hinge, press 
the tooth against the fibre and bend the tongue to break the end off.
These are better than potato peelers for beginners, but not as good 
for experts, and they waste an inch of fibre if you use them properly. 
If you try to waste less fibre, the gadget doesn't hold the fibre well 
and it takes as much skill to get a good cleave as with a potato peeler. 
I guess the choice depends on how much cleaving you expect to do.

>your fiber, you should analyze its end through a microscope. If it is 

Oh, so I'm not supposed to get 40dB of insertion loss? You mean I should
have checked my cleave before proceeding with a week-long experiment?

>well cleaved, you will find out that the surface of the is very flat with 
>no cheaps or breaks.

Indeed. Gotta watch those cheaps. And if you make chips with a potato peeler
does that make them potato chips? :-) Seriously, checking cleaves is a must.

Jody Levine
Ontario Hydro Research
Toronto, Ontario, Canada

Newsgroups: sci.optics
From: nawaz@tellus.unik.no (Muhammad Nawaz)
Subject: * REFLCTION MODULATOR *
Keywords: Semiconductor devices, optical modulation,
Organization: Universitetsstudiene paa Kjeller (UNIK), University of Oslo, Norway
Date: Wed, 29 Jul 92 14:53:47 GMT

modulators, MQW modulators.

Does anubody know about the maximum speed (in time or
frequency domain) response of the GAAs/AlGaAs MQW(multiple quantum well)
reflection modulator used in the optical communication system? To my
knowledge, the maximum speed so far attained for this material
system(GAAs/AlGaAs) is 10 GHz.
From: hnr@ecs.soton.ac.uk (Harvey Rutt)
Newsgroups: sci.optics
Subject: Re: Looking under water with your eyes open
Date: 30 Jul 92 18:27:54 GMT

I am intriqued by this! I swim a lot, and am short sighted, I don't
recall the exact prescription but I think about -10dioptres.
Anyway with no glasses my *furthest* distance of clear vision is 10cm or
so.
Underwater I have no doubt I can see better - for example I find
objects on the pool bottom I would have no chance of finding in air
with no glasses.
But if I only have the 15 dioptre lens left my eyeball needs to 
reach an awful long way into my
head to get a decent image! Is the index of the
cornea really that close to that of water? It will probably be
slightly higher, very few solids get that low. 

I guess I am just comparing two very badly defocussed images and the
one under water happens to work out better.

What do normal sighted people see under water? - I have never thought
to ask- just how blurred are things? According to the figures given it
ought to be very bad indeed.
Any more comments?
Harvey Rutt, Southampton UK
Newsgroups: sci.optics
From: hoesel@igc.ethz.ch (Frans van Hoesel)
Subject: curve fitting to narrow band transmission filter
Organization: University of Groningen, the Netherlands
Date: Thu, 23 Jul 1992 19:18:10 GMT

Hi there,

I'm not sure in which newsgroup to put this problem, so i decided
to put in the group for which my problem is a problem.
I have a extremely high resolution spectrometer (in development)
but to give me a quick look at the resulting stellar spectrum, I
have to correct for the transmission profile of a narrow band
interference profile. As this is solely intended to give en-users
(and me) a quick look at the resulting spectrum I just simply 
want to divide my resulting spectrum by an extreemly smooth
curve representing the transmission profile.

As far as i can tell a transmission profile of a filter starts at zero
(at least with the very low intensities i'm using-->no detectable photons)
goes up to a constant (choosen to be 1) and goes down again.

Is there a good way of doing this, without measuring the actual profile.
It doesn't need to be very accurate. So to put it simple how to make a smooth
curve that goes from zero to 1 and back to zero, without anything else
known about the profile (besides that I must fit it to my data!)

That may not be very easy, but it would be very nice, because it would
'correct' for other systematic errors from the instrument as well
(these are known and can be removed with a lot of work, but i want
just a quick look)

any suggestions or references?

desperatly seeking frans.

Newsgroups: sci.optics
From: SICKMOEL@rzmain.rz.uni-ulm.de (Sickmoeller Markus)
Subject: RE: Reflection modulators
Organization: University of Ulm, Germany
Date: Thu, 30 Jul 1992 11:39:12 GMT
X-News-Reader: VMS NEWS 1.23

Hi !

We have made reflection modulators in this material-system
and testet them up to 18 GHz. This frequency-limit is only
because there where no microwave-amplifiers with higer
frequencys available.

By, Markus
From: vls@cube.handheld.com (Vern Stant)
Newsgroups: sci.optics
Subject: HELP lux, lumens,etc.
Date: 28 Jul 92 18:14:16 GMT
Organization: Hand Held Products, Inc.

Can anyone explan what lux, lumens, and footcandles are?
I hope this isn't covered in a FAQ.  I looked up lumans
and got:

A unit of luminous flux equal to the light emitted in a unit solid angle by a  
uniform point source of one candle intensity.

I'm confused.

Thanks,
Vern
--
Vern Stant              | The opinions expressed herein are
Hand Held Products, Inc.| not necessarily those of Hand 
804.784.3090 voice      | Held Products, Inc., and may not 
804.784.3147 FAX        | even be mine. Use at your own risk
Newsgroups: sci.optics
From: rcg@delphi.dseg.ti.com (bob gibbons)
Subject: Re: HELP wiith BINOCULARS....!!!!
Organization: Texas Instruments
	<1992Jul21.085054.3365@email.tuwien.ac.at>
Date: Fri, 24 Jul 1992 19:22:24 GMT


Getting in late to this thread, but just to clear up a possible
misconception regarding field of view in binoculars. An earlier post
suggested that 

> ... A good optical instrument has the right field of view:
>
> * if it is too big, the picture is graeter than the diameter of your eye  
> lens, this would be an 'overhead'.
> * if it is too small, you will see a black frame around the picture. 

Whether or not you see a "black frame" around the image is a function of
the match between the eye pupil diameter and position and the
binocular's exit pupil and position, field of view in not relevent. The
description of the binocular gives information on the exit pupil size of
the instrument. For example, a set of 10x50mm binoculars will have an
exit pupil 50mm/10=5mm. This can be compared with the range of eye pupil
sizes of from 8mm to 2mm. In the case where the binocular exit pupil is
greater than the eye pupil, the energy is simply wasted, aborbed in the
iris.

An important point in selecting binoculars that I have not yet seen
mentioned related to the position of the exit pupil of the binoculars
with respect to the back of the instrument. This is called the "eye
relief". Typical numbers might range from 5mm to 25mm or more. Ideally,
the users would place his eye pupil in the same location occupied by the
binocular's exit pupil. If this eye relief number is too short, it might
be difficult or impossible (particularily if the user has eyeglasses) to
place the eye pupil at this exit pupil. Failure to match pupil locations
can lead to the above mentioned "black frame". 

In summary, ask about the eye relief of the intended instrument, and
keep in mind whether the users will be using eyeglasses.  Most
specilized optical houses selling binoculars will list this eye relief
number prominently with the standard specs such as 10x50mm.
--
Bob Gibbons				Texas Instruments
Internet: rcg@delphi.dseg.ti.com	Dallas, TX
From: ulrich@tpki.toppoint.de (Ulrich Gall)
Newsgroups: sci.optics
Subject: Looking under water with your eyes open
Date: 26 Jul 92 16:23:42 GMT
Organization: Toppoint Mailbox e.V.


When you look under water with your eyes open, it looks blurry
of course.

But what if you are VERY short-sighted?

Did anyone ever calculate this all the way through? Or try it?


	Ulrich
-- 
Ulrich Gall		ulrich@tpki.toppoint.de
2300 Klausdorf
From: hansen@rddvax.decnet.lockheed.com
Newsgroups: sci.optics
Subject: Re: HELP/BINOCULARS - pupil size
Date: 22 Jul 92 20:05:19 GMT
Organization: Lockheed Palo Alto Research Labs

> Also the exit
> pupil is important for seeing in dim light.  Your eye will dilate to around 8
> mm.  So for night viewing the exit pupil should be around this size.
> 
> ********************************************************
> Don Silva (Phd)

	Actually, according to an article in the May, 1992 issue of Sky and 
Telescope, dark-adapted pupil sizes range from 7 mm at age 20 to 5 mm at age 
75, BUT the variation is easily +/- 1.5 mm!! The article also shows how to 
measure your pupil size, in addition to the general discussion of pupils.

				Glenn Hansen
and cookie says:
 Love with nature through a powerful work.
From: hnr@ecs.soton.ac.uk (Harvey Rutt)
Newsgroups: sci.optics
Subject: Resolution Charts
Keywords: MIL-STD
Date: 24 Jul 92 09:24:14 GMT

These are specified in a MIL-STD document, I'm almost sure. I recall
having a copy years ago but can't find it. There must be a list of
these specs somewhere!
Does anyone know if there is a database of MIL-STDs which can be
searched for standards on a particular subject?
Harvey Rutt, Southampton UK
 
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