Linear polarizer

[Dannycyc]

I have a polarized glasses that I took from IMAX theater. I tested it
on my PC monitor and found that the left lens is horizontally
polarized and the right lens is vertically polarized. But if I flipped
over (not turned an angle) the glasses, the same left lens becomes
vertically polarized and the same right lens becomes horizontally
polarized. (When I say the lens is horizontally polarized, I mean the
horizontally polarized light can pass through the lens.)

That means the polarized lens has a direction. If the light comes from
A side to B side, it is, say horizontally, polarized and if the light
passes from B side to A side, it becomes vertically polarized.
Remember that I did not turn the lens 90 degrees, I think the
polarization of the lens should not be changed. Why is this? Thanks
for your help in advance.

[Phil Hobbs]

On 3/18/2010 1:26 PM, Dannycyc wrote:
>
> I have a polarized glasses that I took from IMAX theater. I tested it
> on my PC monitor and found that the left lens is horizontally
> polarized and the right lens is vertically polarized. But if I flipped
> over (not turned an angle) the glasses, the same left lens becomes
> vertically polarized and the same right lens becomes horizontally
> polarized. (When I say the lens is horizontally polarized, I mean the
> horizontally polarized light can pass through the lens.)
>
> That means the polarized lens has a direction. If the light comes from
> A side to B side, it is, say horizontally, polarized and if the light
> passes from B side to A side, it becomes vertically polarized.
> Remember that I did not turn the lens 90 degrees, I think the
> polarization of the lens should not be changed. Why is this? Thanks
> for your help in advance.

Probably the backing plastic is approximately a 1/2 wave plate, aligned
roughly at 45 degrees to the axis joining the lenses. Thin plastic
sheet is usually birefringent like that, but I can't think why they'd
bother making it precise--unless it's so you can wear them upside down
and backwards!

Cheers

Phil Hobbs

--
Dr Philip C D Hobbs
Principal
ElectroOptical Innovations
55 Orchard Rd
Briarcliff Manor NY 10510
845-480-2058
hobbs at electrooptical dot net
http://electrooptical.net

[Dannycyc]

On Mar 18, 10:43 am, Phil Hobbs
<***@electrooptical.net> wrote:
> On 3/18/2010 1:26 PM, Dannycyc wrote:
>
>
>
> > I have a polarized glasses that I took from IMAX theater.  I tested it
> > on my PC monitor and found that the left lens is horizontally
> > polarized and the right lens is vertically polarized. But if I flipped
> > over (not turned an angle) the glasses, the same left lens becomes
> > vertically polarized and the same right lens becomes horizontally
> > polarized.  (When I say the lens is horizontally polarized, I mean the
> > horizontally polarized light can pass through the lens.)
>
> > That means the polarized lens has a direction. If the light comes from
> > A side to B side, it is, say horizontally, polarized and if the light
> > passes from B side to A side, it becomes vertically polarized.
> > Remember that I did not turn the lens 90 degrees, I think the
> > polarization of the lens should not be changed.  Why is this?  Thanks
> > for your help in advance.
>
> Probably the backing plastic is approximately a 1/2 wave plate, aligned
> roughly at 45 degrees to the axis joining the lenses.  Thin plastic
> sheet is usually birefringent like that, but I can't think why they'd
> bother making it precise--unless it's so you can wear them upside down
> and backwards!
>
> Cheers
>
> Phil Hobbs
>
> --
> Dr Philip C D Hobbs
> Principal
> ElectroOptical Innovations
> 55 Orchard Rd
> Briarcliff Manor NY 10510
> 845-480-2058
> hobbs at electrooptical dot nethttp://electrooptical.net

Interesting... do you mean that cheap plastic linearly polarized lens
is also working like a wave plate in some sense?

Do wave plates and polarizers use totally different material?

-- Danny

[Helpful person]

On Mar 18, 10:43 am, Phil Hobbs
<***@electrooptical.net> wrote:
> On 3/18/2010 1:26 PM, Dannycyc wrote:
>
>
>
> > I have a polarized glasses that I took from IMAX theater.  I tested it
> > on my PC monitor and found that the left lens is horizontally
> > polarized and the right lens is vertically polarized. But if I flipped
> > over (not turned an angle) the glasses, the same left lens becomes
> > vertically polarized and the same right lens becomes horizontally
> > polarized.  (When I say the lens is horizontally polarized, I mean the
> > horizontally polarized light can pass through the lens.)
>
> > That means the polarized lens has a direction. If the light comes from
> > A side to B side, it is, say horizontally, polarized and if the light
> > passes from B side to A side, it becomes vertically polarized.
> > Remember that I did not turn the lens 90 degrees, I think the
> > polarization of the lens should not be changed.  Why is this?  Thanks
> > for your help in advance.
>
> Probably the backing plastic is approximately a 1/2 wave plate, aligned
> roughly at 45 degrees to the axis joining the lenses.  Thin plastic
> sheet is usually birefringent like that, but I can't think why they'd
> bother making it precise--unless it's so you can wear them upside down
> and backwards!
>
> Cheers
>
> Phil Hobbs
>
> --
> Dr Philip C D Hobbs
> Principal
> ElectroOptical Innovations
> 55 Orchard Rd
> Briarcliff Manor NY 10510
> 845-480-2058
> hobbs at electrooptical dot nethttp://electrooptical.net

Don't they use circularly polarized light?

www.richardisher.com

[Dannycyc]

On Mar 18, 12:21 pm, Helpful person <***@yahoo.com> wrote:
> On Mar 18, 10:43 am, Phil Hobbs
>
>
>
>
>
> <***@electrooptical.net> wrote:
> > On 3/18/2010 1:26 PM, Dannycyc wrote:
>
> > > I have a polarized glasses that I took from IMAX theater.  I tested it
> > > on my PC monitor and found that the left lens is horizontally
> > > polarized and the right lens is vertically polarized. But if I flipped
> > > over (not turned an angle) the glasses, the same left lens becomes
> > > vertically polarized and the same right lens becomes horizontally
> > > polarized.  (When I say the lens is horizontally polarized, I mean the
> > > horizontally polarized light can pass through the lens.)
>
> > > That means the polarized lens has a direction. If the light comes from
> > > A side to B side, it is, say horizontally, polarized and if the light
> > > passes from B side to A side, it becomes vertically polarized.
> > > Remember that I did not turn the lens 90 degrees, I think the
> > > polarization of the lens should not be changed.  Why is this?  Thanks
> > > for your help in advance.
>
> > Probably the backing plastic is approximately a 1/2 wave plate, aligned
> > roughly at 45 degrees to the axis joining the lenses.  Thin plastic
> > sheet is usually birefringent like that, but I can't think why they'd
> > bother making it precise--unless it's so you can wear them upside down
> > and backwards!
>
> > Cheers
>
> > Phil Hobbs
>
> > --
> > Dr Philip C D Hobbs
> > Principal
> > ElectroOptical Innovations
> > 55 Orchard Rd
> > Briarcliff Manor NY 10510
> > 845-480-2058
> > hobbs at electrooptical dot nethttp://electrooptical.net
>
> Don't they use circularly polarized light?
>
> www.richardisher.com

I believe the IMAX I went to (Regal Hacienda, Dublin, California) uses
linearly polarized light.

Here's the experiment I did in the IMAX theater: when I tilted my
head, I could see both the left eye and right eye images through my
glasses on the screen and the 3D effect disappeared. Therefore, I
believe the glasses and the IMAX projector light are linearly not
circularly polarized.

-- Danny

[DougD]

In article <c9586c12-7aef-4362-9c32-***@v20g2000prc.googlegroups.com>, Helpful person <***@yahoo.com> wrote:

>Don't they use circularly polarized light?
>
>www.richardisher.com

Yes, or at least they have in the past, as have other "ride film" producers
like Iwerks, Electrosonic (who I did design/build for).. They are less
sensitive to head tilt on motion platforms, or just lazy audience members..

d.

[Dannycyc]

On Mar 18, 11:20 am, Dannycyc <***@gmail.com> wrote:
> On Mar 18, 10:43 am, Phil Hobbs
>
>
>
>
>
> <***@electrooptical.net> wrote:
> > On 3/18/2010 1:26 PM, Dannycyc wrote:
>
> > > I have a polarized glasses that I took from IMAX theater.  I tested it
> > > on my PC monitor and found that the left lens is horizontally
> > > polarized and the right lens is vertically polarized. But if I flipped
> > > over (not turned an angle) the glasses, the same left lens becomes
> > > vertically polarized and the same right lens becomes horizontally
> > > polarized.  (When I say the lens is horizontally polarized, I mean the
> > > horizontally polarized light can pass through the lens.)
>
> > > That means the polarized lens has a direction. If the light comes from
> > > A side to B side, it is, say horizontally, polarized and if the light
> > > passes from B side to A side, it becomes vertically polarized.
> > > Remember that I did not turn the lens 90 degrees, I think the
> > > polarization of the lens should not be changed.  Why is this?  Thanks
> > > for your help in advance.
>
> > Probably the backing plastic is approximately a 1/2 wave plate, aligned
> > roughly at 45 degrees to the axis joining the lenses.  Thin plastic
> > sheet is usually birefringent like that, but I can't think why they'd
> > bother making it precise--unless it's so you can wear them upside down
> > and backwards!
>
> > Cheers
>
> > Phil Hobbs
>
> > --
> > Dr Philip C D Hobbs
> > Principal
> > ElectroOptical Innovations
> > 55 Orchard Rd
> > Briarcliff Manor NY 10510
> > 845-480-2058
> > hobbs at electrooptical dot nethttp://electrooptical.net
>
> Interesting... do you mean that cheap plastic linearly polarized lens
> is also working like a wave plate in some sense?
>
> Do wave plates and polarizers use totally different material?
>
> -- Danny

Here's another test that puzzles me.

I use the same polarized glasses that I took from the IMAX for
testing.
When I wear the glasses and look at my notebook, I find that the right
lens is bright and the left lens is dark.
Then I put my PC facing a mirror. When I wear the same glasses and
look into the mirror, now my right lens is dark and my left lens is
bright.

Does this mean that a reflection from a mirror will change a
horizontally (vertically) polarized light into a vertically
(horizontally) polarized light?

-- Danny

[anorton]

"Dannycyc" <***@gmail.com> wrote in message
news:4f1c9226-c378-4bc6-83d9-***@n39g2000prj.googlegroups.com...
On Mar 18, 11:20 am, Dannycyc <***@gmail.com> wrote:
> On Mar 18, 10:43 am, Phil Hobbs
>
>
>
>
>
> <***@electrooptical.net> wrote:
> > On 3/18/2010 1:26 PM, Dannycyc wrote:
>
> > > I have a polarized glasses that I took from IMAX theater. I tested it
> > > on my PC monitor and found that the left lens is horizontally
> > > polarized and the right lens is vertically polarized. But if I flipped
> > > over (not turned an angle) the glasses, the same left lens becomes
> > > vertically polarized and the same right lens becomes horizontally
> > > polarized. (When I say the lens is horizontally polarized, I mean the
> > > horizontally polarized light can pass through the lens.)
>
> > > That means the polarized lens has a direction. If the light comes from
> > > A side to B side, it is, say horizontally, polarized and if the light
> > > passes from B side to A side, it becomes vertically polarized.
> > > Remember that I did not turn the lens 90 degrees, I think the
> > > polarization of the lens should not be changed. Why is this? Thanks
> > > for your help in advance.
>
> > Probably the backing plastic is approximately a 1/2 wave plate, aligned
> > roughly at 45 degrees to the axis joining the lenses. Thin plastic
> > sheet is usually birefringent like that, but I can't think why they'd
> > bother making it precise--unless it's so you can wear them upside down
> > and backwards!
>
> > Cheers
>
> > Phil Hobbs
>
> > --
> > Dr Philip C D Hobbs
> > Principal
> > ElectroOptical Innovations
> > 55 Orchard Rd
> > Briarcliff Manor NY 10510
> > 845-480-2058
> > hobbs at electrooptical dot nethttp://electrooptical.net
>
> Interesting... do you mean that cheap plastic linearly polarized lens
> is also working like a wave plate in some sense?
>
> Do wave plates and polarizers use totally different material?
>
> -- Danny

Here's another test that puzzles me.

I use the same polarized glasses that I took from the IMAX for
testing.
When I wear the glasses and look at my notebook, I find that the right
lens is bright and the left lens is dark.
Then I put my PC facing a mirror. When I wear the same glasses and
look into the mirror, now my right lens is dark and my left lens is
bright.

Does this mean that a reflection from a mirror will change a
horizontally (vertically) polarized light into a vertically
(horizontally) polarized light?

-- Danny
_________________

These glasses are circularly polaized, not linear polarized. Put them on
and look in a mirror and close one eye. The eye that is open will appear
dark, the eye that is closed will appear clear. (This could be an
interesting method to determine eye preference.)

They are made from a linear polarizer laminated to a quarter waveplate on
the front side. However, the quarter wave film is not perfect. Look at them
from the front and rotate a linear polarizer in front. You will see colors
which means that some wavelengths are slightly elliptically polarized. This
makes me think that they take care to orient the filters in the glasses
(based on the linear polarizer direction) while the movie projector uses
similar filters oriented at 90 degrees. That would maximize the contrast at
all wavelengths.
--
Adam Norton

Norton Engineered Optics
www.nortonoptics.com

(Remove antispam feature before replying)

[anorton]

"anorton" <***@removethis.ix.netcom.com> wrote in message
news:***@earthlink.com...
>
> "Dannycyc" <***@gmail.com> wrote in message
> news:4f1c9226-c378-4bc6-83d9-***@n39g2000prj.googlegroups.com...
> On Mar 18, 11:20 am, Dannycyc <***@gmail.com> wrote:
>> On Mar 18, 10:43 am, Phil Hobbs
>>
>>
>>
>>
>>
>> <***@electrooptical.net> wrote:
>> > On 3/18/2010 1:26 PM, Dannycyc wrote:
>>
>> > > I have a polarized glasses that I took from IMAX theater. I tested it
>> > > on my PC monitor and found that the left lens is horizontally
>> > > polarized and the right lens is vertically polarized. But if I
>> > > flipped
>> > > over (not turned an angle) the glasses, the same left lens becomes
>> > > vertically polarized and the same right lens becomes horizontally
>> > > polarized. (When I say the lens is horizontally polarized, I mean the
>> > > horizontally polarized light can pass through the lens.)
>>
>> > > That means the polarized lens has a direction. If the light comes
>> > > from
>> > > A side to B side, it is, say horizontally, polarized and if the light
>> > > passes from B side to A side, it becomes vertically polarized.
>> > > Remember that I did not turn the lens 90 degrees, I think the
>> > > polarization of the lens should not be changed. Why is this? Thanks
>> > > for your help in advance.
>>
>> > Probably the backing plastic is approximately a 1/2 wave plate, aligned
>> > roughly at 45 degrees to the axis joining the lenses. Thin plastic
>> > sheet is usually birefringent like that, but I can't think why they'd
>> > bother making it precise--unless it's so you can wear them upside down
>> > and backwards!
>>
>> > Cheers
>>
>> > Phil Hobbs
>>
>> > --
>> > Dr Philip C D Hobbs
>> > Principal
>> > ElectroOptical Innovations
>> > 55 Orchard Rd
>> > Briarcliff Manor NY 10510
>> > 845-480-2058
>> > hobbs at electrooptical dot nethttp://electrooptical.net
>>
>> Interesting... do you mean that cheap plastic linearly polarized lens
>> is also working like a wave plate in some sense?
>>
>> Do wave plates and polarizers use totally different material?
>>
>> -- Danny
>
> Here's another test that puzzles me.
>
> I use the same polarized glasses that I took from the IMAX for
> testing.
> When I wear the glasses and look at my notebook, I find that the right
> lens is bright and the left lens is dark.
> Then I put my PC facing a mirror. When I wear the same glasses and
> look into the mirror, now my right lens is dark and my left lens is
> bright.
>
> Does this mean that a reflection from a mirror will change a
> horizontally (vertically) polarized light into a vertically
> (horizontally) polarized light?
>
> -- Danny
> _________________
>
> These glasses are circularly polaized, not linear polarized. Put them on
> and look in a mirror and close one eye. The eye that is open will appear
> dark, the eye that is closed will appear clear. (This could be an
> interesting method to determine eye preference.)
>
> They are made from a linear polarizer laminated to a quarter waveplate on
> the front side. However, the quarter wave film is not perfect. Look at
> them from the front and rotate a linear polarizer in front. You will see
> colors which means that some wavelengths are slightly elliptically
> polarized. This makes me think that they take care to orient the filters
> in the glasses (based on the linear polarizer direction) while the movie
> projector uses similar filters oriented at 90 degrees. That would
> maximize the contrast at all wavelengths.
> --
> Adam Norton
>
> Norton Engineered Optics
> www.nortonoptics.com
>
> (Remove antispam feature before replying)
>

Sorry, I re-read your post. I thought you were looking at yourself in the
mirror. But I realized you are looking at your PC display. What you see is
explained if your PC is linearly polarized at 45 deg. (as is mine) and the
glasses are also linearly polarized at +/- 45 deg.

What I was talking about above are the 3D glasses used in Avatar, for
example.
--
Adam Norton

Norton Engineered Optics
www.nortonoptics.com

(Remove antispam feature before replying)

[Dannycyc]

On Mar 18, 1:29 pm, "anorton" <***@removethis.ix.netcom.com>
wrote:

> Sorry, I re-read your post. I thought you were looking at yourself in the
> mirror. But I realized you are looking at your PC display.  What you see is
> explained if your PC is linearly polarized at 45 deg. (as is mine) and the
> glasses are also linearly polarized at +/- 45 deg.
>
> What I was talking about above are the 3D glasses used in Avatar, for
> example.
> --
> Adam Norton
>
> Norton Engineered Opticswww.nortonoptics.com
>
> (Remove antispam feature before replying)

Hi Adam,

Your explanation sounds reasonable. Thanks!

Then is IMAX 3D also polarized at 45/135 degree?

Can anyone confirm this?

-- Danny

[Phil Hobbs]

On 3/18/2010 2:49 PM, Dannycyc wrote:
> On Mar 18, 11:20 am, Dannycyc<***@gmail.com> wrote:
>> On Mar 18, 10:43 am, Phil Hobbs
>>
>>
>>
>>
>>
>> <***@electrooptical.net> wrote:
>>> On 3/18/2010 1:26 PM, Dannycyc wrote:
>>
>>>> I have a polarized glasses that I took from IMAX theater. I tested it
>>>> on my PC monitor and found that the left lens is horizontally
>>>> polarized and the right lens is vertically polarized. But if I flipped
>>>> over (not turned an angle) the glasses, the same left lens becomes
>>>> vertically polarized and the same right lens becomes horizontally
>>>> polarized. (When I say the lens is horizontally polarized, I mean the
>>>> horizontally polarized light can pass through the lens.)
>>
>>>> That means the polarized lens has a direction. If the light comes from
>>>> A side to B side, it is, say horizontally, polarized and if the light
>>>> passes from B side to A side, it becomes vertically polarized.
>>>> Remember that I did not turn the lens 90 degrees, I think the
>>>> polarization of the lens should not be changed. Why is this? Thanks
>>>> for your help in advance.
>>
>>> Probably the backing plastic is approximately a 1/2 wave plate, aligned
>>> roughly at 45 degrees to the axis joining the lenses. Thin plastic
>>> sheet is usually birefringent like that, but I can't think why they'd
>>> bother making it precise--unless it's so you can wear them upside down
>>> and backwards!
>>
>>> Cheers
>>
>>> Phil Hobbs
>>
>>> --
>>> Dr Philip C D Hobbs
>>> Principal
>>> ElectroOptical Innovations
>>> 55 Orchard Rd
>>> Briarcliff Manor NY 10510
>>> 845-480-2058
>>> hobbs at electrooptical dot nethttp://electrooptical.net
>>
>> Interesting... do you mean that cheap plastic linearly polarized lens
>> is also working like a wave plate in some sense?
>>
>> Do wave plates and polarizers use totally different material?
>>
>> -- Danny
>
> Here's another test that puzzles me.
>
> I use the same polarized glasses that I took from the IMAX for
> testing.
> When I wear the glasses and look at my notebook, I find that the right
> lens is bright and the left lens is dark.
> Then I put my PC facing a mirror. When I wear the same glasses and
> look into the mirror, now my right lens is dark and my left lens is
> bright.
>
> Does this mean that a reflection from a mirror will change a
> horizontally (vertically) polarized light into a vertically
> (horizontally) polarized light?
>
> -- Danny
>
>

Sounds like a circular polarizer then. Those consist of linear
polarizers laminated to quarter wave plates, and they do have
front-to-back issues. Do they work as normal polaroid sunglasses
(i.e. reduce glare from oblique reflections from dielectric surfaces)?

Cheers

Phil Hobbs

--
Dr Philip C D Hobbs
Principal
ElectroOptical Innovations
55 Orchard Rd
Briarcliff Manor NY 10510
845-480-2058
hobbs at electrooptical dot net
http://electrooptical.net

[Dannycyc]

>
> Sounds like a circular polarizer then.  Those consist of linear
> polarizers laminated to quarter wave plates, and they do have
> front-to-back issues.    Do they work as normal polaroid sunglasses
> (i.e. reduce glare from oblique reflections from dielectric surfaces)?
>
> Cheers
>
> Phil Hobbs
>
> --
> Dr Philip C D Hobbs
> Principal
> ElectroOptical Innovations
> 55 Orchard Rd
> Briarcliff Manor NY 10510
> 845-480-2058
> hobbs at electrooptical dot nethttp://electrooptical.net

I will go get a pair of polarized sunglasses to double check the 3D
glasses I got from the IMAX.

-- Danny

[Dannycyc]

On Mar 18, 2:41 pm, Dannycyc <***@gmail.com> wrote:
> > Sounds like a circular polarizer then.  Those consist of linear
> > polarizers laminated to quarter wave plates, and they do have
> > front-to-back issues.    Do they work as normal polaroid sunglasses
> > (i.e. reduce glare from oblique reflections from dielectric surfaces)?
>
> > Cheers
>
> > Phil Hobbs
>
> > --
> > Dr Philip C D Hobbs
> > Principal
> > ElectroOptical Innovations
> > 55 Orchard Rd
> > Briarcliff Manor NY 10510
> > 845-480-2058
> > hobbs at electrooptical dot nethttp://electrooptical.net
>
> I will go get a pair of polarized sunglasses to double check the 3D
> glasses I got from the IMAX.
>
> -- Danny

I got a pair of polarized sunglasses and used it to test the 3D
glasses from IMAX.
I am pretty sure that the 3D glasses is polarized at 45/135 degree.

Thank you all for the discussion.

-- Danny

[AES]

The length of this thread is forcing me to re-tell the story of the
expensive Sun LCD monitor I bought some years ago whose output was
linearly polarized exactly wrong for anyone wearing polarized sun
glasses -- horrible muddy total unusable display of just smears of color
when i first turned it on..

Nearly got sent back to Sun, until I realized it was fine when wearing
my ordinary glasses, and did some testing.

And the two large-screen Cinema Displays I checked out in the Apple
Store a few years ago (21" and 24" models, I believe): one of them
polarized exactly right, the other exactly wrong.

And the small credit card swiping units in some 7/11s that are also
polarized exactly wrong.

Most laptops seem to be polarized at 45 degrees, or else circular, ergo
are OK with polarized sunglasses except for 3 dB loss in brightness
(which is hardly noticeable in most cases).

[Salmon Egg]

In article <siegman-***@sciid-srv02.med.tufts.edu>,
AES <***@stanford.edu> wrote:

> The length of this thread is forcing me to re-tell the story of the
> expensive Sun LCD monitor I bought some years ago whose output was
> linearly polarized exactly wrong for anyone wearing polarized sun
> glasses -- horrible muddy total unusable display of just smears of color
> when i first turned it on..
>
> Nearly got sent back to Sun, until I realized it was fine when wearing
> my ordinary glasses, and did some testing.
>
> And the two large-screen Cinema Displays I checked out in the Apple
> Store a few years ago (21" and 24" models, I believe): one of them
> polarized exactly right, the other exactly wrong.
>
> And the small credit card swiping units in some 7/11s that are also
> polarized exactly wrong.
>
> Most laptops seem to be polarized at 45 degrees, or else circular, ergo
> are OK with polarized sunglasses except for 3 dB loss in brightness
> (which is hardly noticeable in most cases).

I had the same problem with the instrument cluster of a Toyota van. I
could not read the odometer easily while wearing polarized sunglasses.
Luckily, it is not something that needs to be done often. The numbers
can be made marginally visible by tilting your head.

Bill

--
An old man would be better off never having been born.

[o***@uakron.edu]

Watch out, a recent trip to Walmart's fishing section revealed their
fishing glasses are circular. Argh!!
Needed polarized sun glasses on a production line... ended up making
them.
Steve

[Louis Boyd]

***@uakron.edu wrote:
> Watch out, a recent trip to Walmart's fishing section revealed their
> fishing glasses are circular. Argh!!

That's so sunshine reflecting off your eyes won't scare the fish.

[Salmon Egg]

In article <hnvvu5$ceb$***@onion.ccit.arizona.edu>,
Louis Boyd <***@apt0.sao.arizona.edu> wrote:

> ***@uakron.edu wrote:
> > Watch out, a recent trip to Walmart's fishing section revealed their
> > fishing glasses are circular. Argh!!
>
> That's so sunshine reflecting off your eyes won't scare the fish.

That's strange, All along I thought that my fly fishing buddy was a
better fisherman. And he wouldn't have known about circular polarization
if it bit him on the ass. (:=(

Bill

--
An old man would be better off never having been born.

[Salmon Egg]

In article
<2dd2e9ca-71e2-45fa-abd2-***@g28g2000yqh.googlegroups.com>,
***@uakron.edu wrote:

> Watch out, a recent trip to Walmart's fishing section revealed their
> fishing glasses are circular. Argh!!
> Needed polarized sun glasses on a production line... ended up making
> them.
> Steve

That does not have to be a problem. A circular polarizer consists of a
sandwich with a linear polarizer on one side and a half-wave plate on
the other. As long as the linear polarizer is facing the scene
(half-wave closer to the eye) and properly oriented, it should be as
effective in suppressing glare as a linear polarizer.

Bill

--
An old man would be better off never having been born.

[Samuel M. Goldwasser]

Salmon Egg <***@sbcglobal.net> writes:

> In article
> <2dd2e9ca-71e2-45fa-abd2-***@g28g2000yqh.googlegroups.com>,
> ***@uakron.edu wrote:
>
> > Watch out, a recent trip to Walmart's fishing section revealed their
> > fishing glasses are circular. Argh!!
> > Needed polarized sun glasses on a production line... ended up making
> > them.
> > Steve
>
> That does not have to be a problem. A circular polarizer consists of a
> sandwich with a linear polarizer on one side and a half-wave plate on
> the other. As long as the linear polarizer is facing the scene
> (half-wave closer to the eye) and properly oriented, it should be as
> effective in suppressing glare as a linear polarizer.

Quarter waveplate. :)

--
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[Salmon Egg]

In article <***@repairfaq.org>,
***@repairfaq.org (Samuel M. Goldwasser) wrote:

> Quarter waveplate. :)


Correct! My error.

Bill

--
An old man would be better off never having been born.

[Helpful person]

On Mar 18, 8:46 pm, Salmon Egg <***@sbcglobal.net> wrote:
>
> I had the same problem with the instrument cluster of a Toyota van. I
> could not read the odometer easily while wearing polarized sunglasses.
> Luckily, it is not something that needs to be done often. The numbers
> can be made marginally visible by tilting your head.
>
> Bill
>
> --
> An old man would be better off never having been born.

I had a problem years ago with my Fiat 128. (I know, horrible car.)
There was a green warning light on the dash that lit up when the
headlamps were on high beam (brights for Americans). This reflected
nicely off the windshield near the center of my field of view. I
solved the problem (no, not with an axe) but with a piece of polaroid
film stuck over the the light. This eliminated the problem as the
windshield was very close to the Brewster angle.

www.richardfisher.com

[DougD]

In article <93b9f078-9cba-4515-a3ab-***@u15g2000prd.googlegroups.com>, Dannycyc <***@gmail.com> wrote:
>
>I have a polarized glasses that I took from IMAX theater. I tested it
>on my PC monitor and found that the left lens is horizontally
>polarized and the right lens is vertically polarized. But if I flipped
>over (not turned an angle) the glasses, the same left lens becomes
>vertically polarized and the same right lens becomes horizontally
>polarized. (When I say the lens is horizontally polarized, I mean the
>horizontally polarized light can pass through the lens.)
>
>That means the polarized lens has a direction. If the light comes from
>A side to B side, it is, say horizontally, polarized and if the light
>passes from B side to A side, it becomes vertically polarized.
>Remember that I did not turn the lens 90 degrees, I think the
>polarization of the lens should not be changed. Why is this? Thanks
>for your help in advance.

I'm probably going to put my foot in the mouth on this.. When I was working
in the special venue film biz, we'd use circular polarized glasses as they
are less sensitive to head tilt when the audience is say on a moving platform
in a "ride film".. I know Imax has used circ pol. in the past, but I can't say
for sure on what is in use now..

d.

[Phil Hobbs]

On 3/18/2010 9:33 PM, DougD wrote:
> In article<93b9f078-9cba-4515-a3ab-***@u15g2000prd.googlegroups.com>, Dannycyc<***@gmail.com> wrote:
>>
>> I have a polarized glasses that I took from IMAX theater. I tested it
>> on my PC monitor and found that the left lens is horizontally
>> polarized and the right lens is vertically polarized. But if I flipped
>> over (not turned an angle) the glasses, the same left lens becomes
>> vertically polarized and the same right lens becomes horizontally
>> polarized. (When I say the lens is horizontally polarized, I mean the
>> horizontally polarized light can pass through the lens.)
>>
>> That means the polarized lens has a direction. If the light comes from
>> A side to B side, it is, say horizontally, polarized and if the light
>> passes from B side to A side, it becomes vertically polarized.
>> Remember that I did not turn the lens 90 degrees, I think the
>> polarization of the lens should not be changed. Why is this? Thanks
>> for your help in advance.
>
> I'm probably going to put my foot in the mouth on this.. When I was working
> in the special venue film biz, we'd use circular polarized glasses as they
> are less sensitive to head tilt when the audience is say on a moving platform
> in a "ride film".. I know Imax has used circ pol. in the past, but I can't say
> for sure on what is in use now..
>
> d.

Using normal circular polarizer material would allow using the same
glasses for both--just bend the arms the other way, so the glasses are
reversed front-to-back. Clever.

Cheers

Phil

--
Dr Philip C D Hobbs
Principal
ElectroOptical Innovations
55 Orchard Rd
Briarcliff Manor NY 10510
845-480-2058
hobbs at electrooptical dot net
http://electrooptical.net

[DougD]

In article <***@electrooptical.net>, Phil Hobbs <***@electrooptical.net> wrote:

>
>Using normal circular polarizer material would allow using the same
>glasses for both--just bend the arms the other way, so the glasses are
>reversed front-to-back. Clever.

I just had a press release show up here regarding Technicolor's new
film based 3D system to offer an alternative to having to switch to
an all digital format for cinema's that want to show the current crop
of 3D features. They are also going to be using circ. polarizers for
their glasses as well, both for the better quality of extinction with
their over/under system, and to also be compatable with everyone
else so that you can use glasses left over from a DigCin showing.
Knowing how slack the theater owners are about keeping the
glasses clean between shows, I'd be inclined to just "invest" in
a perm. pair if I were a regular theater goer, especially now as
there's going to be a min. of at least 19, 3D features per year for
at least the next 5 years. And who knows, maybe they will start
to re-issue "classics" in 3D... I can see it now, "Driving Miss
Daisy, and The Color Purple, in 3D"...

d.

[Sz]

Am Freitag, 19. März 2010 19:04:14 UTC+1 schrieb DougD:
> In article <***@electrooptical.net>, Phil Hobbs <***@electrooptical.net> wrote:
>
> >
> >Using normal circular polarizer material would allow using the same
> >glasses for both--just bend the arms the other way, so the glasses are
> >reversed front-to-back. Clever.
>
> I just had a press release show up here regarding Technicolor's new
> film based 3D system to offer an alternative to having to switch to
> an all digital format for cinema's that want to show the current crop
> of 3D features. They are also going to be using circ. polarizers for
> their glasses as well, both for the better quality of extinction with
> their over/under system, and to also be compatable with everyone
> else so that you can use glasses left over from a DigCin showing.
> Knowing how slack the theater owners are about keeping the
> glasses clean between shows, I'd be inclined to just "invest" in
> a perm. pair if I were a regular theater goer, especially now as
> there's going to be a min. of at least 19, 3D features per year for
> at least the next 5 years. And who knows, maybe they will start
> to re-issue "classics" in 3D... I can see it now, "Driving Miss
> Daisy, and The Color Purple, in 3D"...
>
> d.

Hi DougD, are you living ?

[Salmon Egg]

In article
<93b9f078-9cba-4515-a3ab-***@u15g2000prd.googlegroups.com>,
Dannycyc <***@gmail.com> wrote:

> I have a polarized glasses that I took from IMAX theater. I tested it
> on my PC monitor and found that the left lens is horizontally
> polarized and the right lens is vertically polarized. But if I flipped
> over (not turned an angle) the glasses, the same left lens becomes
> vertically polarized and the same right lens becomes horizontally
> polarized. (When I say the lens is horizontally polarized, I mean the
> horizontally polarized light can pass through the lens.)
>
> That means the polarized lens has a direction. If the light comes from
> A side to B side, it is, say horizontally, polarized and if the light
> passes from B side to A side, it becomes vertically polarized.
> Remember that I did not turn the lens 90 degrees, I think the
> polarization of the lens should not be changed. Why is this? Thanks
> for your help in advance.

You managed to confuse me.

Bill

--
An old man would be better off never having been born.