SUN GLASSES

On Thursday, June 13, 2013 3:12:14 PM UTC-7, noel.wade wrote:
P7 has the best answer...



But Let's step back to facts, shall we?



Polarized lenses literally block light, unless the light-waves are

oriented at a specific angle to the lens.



Almost all LCDs (including PDAs, cell-phones, iPads, and even simple

displays like Cambridge *-NAV devices or digial variometers) have 1 or

2 polarized screens, as part of how they work. See he

http://en.wikipedia.org/wiki/Liquid-crystal_display



Stacking multiple polarizing filters in the proper orientation lets

light pass through. But stacking them in the wrong orientation causes

the light passing through the first filter to be BLOCKED by the

second.



Your polarized sunglasses _are_ a "second filter", sitting between

your eyeballs and the LCD screens in your cockpit. Ergo, if the

orientation of your sunglasses' polarized surface is not near the same

angle of your electronic displays, the visibility of your instruments

will be negatively impacted. Here are two video demonstrations of

this:

http://www.youtube.com/watch?v=GkLBMAY406Q

http://www.youtube.com/watch?v=HcQWAqL2JUw



Polarized sunglasses are not all manufactured the same; and even

different batches of the same sunglasses may not always have the

orientation to the polarized lenses - don't assume that because your

glasses work for you, that you can recommend them to others or that

you can simply buy another pair of the same, and have them work

identically. Additionally, just because you find glasses that may work

with _your_ cockpit instruments and canopy, do _not_ assume that it

will work with _all_ instruments or canopies. Finally, don't assume

that all of your instrument displays have the same polarization on

their screens. I have polarized lenses that work fine when viewing

some of my instruments, but not with others (unless you rotate the

glasses 90-degrees). Also, these polarized sunglasses worked fine

with my DG-300 canopy, but created horrible moire & checkerboard

patterns on a couple of Diamond DA-20 rental aircraft canopies.



If you're going to fly with a lot of cockpit electronics, I strongly

recommend against polarized lenses because you don't want to be

distracted or fumbling with your instruments because of this effect.

There are plenty of effective non-polarized sunglasses out there that

give you good visibility and protection.



Lastly, if you're going to be flying in a club or rental environment,

where you switch ships with any regularity, do NOT assume that

polarized sunglasses which work in one cockpit will work in another.



--Noel

Good points.
I guess it all boils down to "it depends". Polarized glasses always worked for me in the gliders I flew, but I agree this is not always going to be the case.
So the solution is to have a spare non polarized glasses with you in case there is an issue.

Ramy

At 22:20 12 June 2013, wrote:
I'm getting new sun glasses, should I get Polarized or not, what works
best
for flying gliders???
The ones I'm looking at are also anti-glare lenses.

Thanks
Glen


When I was in to gliding I always flew on a sunny day with Oakley wiretap
fire iridium polarized sunglassed, to be specific.
(http://www.oakley.com/products/1252/2794).

No colour loss, no glare and on a blue day you can see 'haze caps' of
thermals which would otherwise be invisible - I would recommend them.

At 00:11 14 June 2013, Ramy wrote:
On Thursday, June 13, 2013 3:12:14 PM UTC-7, noel.wade
wrote:
P7 has the best answer...



But Let's step back to facts, shall we?



Polarized lenses literally block light, unless the light-waves
are

oriented at a specific angle to the lens.



Almost all LCDs (including PDAs, cell-phones, iPads, and
even simple

displays like Cambridge *-NAV devices or digial
variometers) have 1 or

2 polarized screens, as part of how they work. See he

http://en.wikipedia.org/wiki/Liquid-crystal_display



Stacking multiple polarizing filters in the proper orientation
lets

light pass through. But stacking them in the wrong
orientation causes

the light passing through the first filter to be BLOCKED by
the

second.



Your polarized sunglasses _are_ a "second filter", sitting
between

your eyeballs and the LCD screens in your cockpit. Ergo, if
the

orientation of your sunglasses' polarized surface is not near
the same

angle of your electronic displays, the visibility of your
instruments

will be negatively impacted. Here are two video
demonstrations of

this:

http://www.youtube.com/watch?v=GkLBMAY406Q

http://www.youtube.com/watch?v=HcQWAqL2JUw



Polarized sunglasses are not all manufactured the same;
and even

different batches of the same sunglasses may not always
have the

orientation to the polarized lenses - don't assume that
because your

glasses work for you, that you can recommend them to
others or that

you can simply buy another pair of the same, and have
them work

identically. Additionally, just because you find glasses that
may work

with _your_ cockpit instruments and canopy, do _not_
assume that it

will work with _all_ instruments or canopies. Finally, don't
assume

that all of your instrument displays have the same
polarization on

their screens. I have polarized lenses that work fine when
viewing

some of my instruments, but not with others (unless you
rotate the

glasses 90-degrees). Also, these polarized sunglasses
worked fine

with my DG-300 canopy, but created horrible moire &
checkerboard

patterns on a couple of Diamond DA-20 rental aircraft
canopies.



If you're going to fly with a lot of cockpit electronics, I
strongly

recommend against polarized lenses because you don't
want to be

distracted or fumbling with your instruments because of this
effect.

There are plenty of effective non-polarized sunglasses out
there that

give you good visibility and protection.



Lastly, if you're going to be flying in a club or rental
environment,

where you switch ships with any regularity, do NOT assume
that

polarized sunglasses which work in one cockpit will work in
another.



--Noel

Good points.
I guess it all boils down to "it depends". Polarized glasses
always worked
for me in the gliders I flew, but I agree this is not always going
to be
the case.
So the solution is to have a spare non polarized glasses with
you in case
there is an issue.

Ramy

Polarised sunglasses should genarally be expected to have
vertical polarization because the whole point about reducing
glare from water surfaces etc is that the light reflected of the
surface to the eye tends to be polarised horizontally.

On another topic - genuine question - do polarised lenses made
without a UV absorbing tint, and without a UV absorbing lens
material such as polycarbonate, reduce UV transmission more
than in proportion to the reduction in general light
transmission?

John Galloway

At 14:08 14 June 2013, John Galloway wrote:
At 00:11 14 June 2013, Ramy wrote:
On Thursday, June 13, 2013 3:12:14 PM UTC-7, noel.wade
wrote:
P7 has the best answer...



But Let's step back to facts, shall we?



Polarized lenses literally block light, unless the light-waves
are

oriented at a specific angle to the lens.



Almost all LCDs (including PDAs, cell-phones, iPads, and
even simple

displays like Cambridge *-NAV devices or digial
variometers) have 1 or

2 polarized screens, as part of how they work. See he

http://en.wikipedia.org/wiki/Liquid-crystal_display



Stacking multiple polarizing filters in the proper orientation
lets

light pass through. But stacking them in the wrong
orientation causes

the light passing through the first filter to be BLOCKED by
the

second.



Your polarized sunglasses _are_ a "second filter", sitting
between

your eyeballs and the LCD screens in your cockpit. Ergo, if
the

orientation of your sunglasses' polarized surface is not near
the same

angle of your electronic displays, the visibility of your
instruments

will be negatively impacted. Here are two video
demonstrations of

this:

http://www.youtube.com/watch?v=GkLBMAY406Q

http://www.youtube.com/watch?v=HcQWAqL2JUw



Polarized sunglasses are not all manufactured the same;
and even

different batches of the same sunglasses may not always
have the

orientation to the polarized lenses - don't assume that
because your

glasses work for you, that you can recommend them to
others or that

you can simply buy another pair of the same, and have
them work

identically. Additionally, just because you find glasses that
may work

with _your_ cockpit instruments and canopy, do _not_
assume that it

will work with _all_ instruments or canopies. Finally, don't
assume

that all of your instrument displays have the same
polarization on

their screens. I have polarized lenses that work fine when
viewing

some of my instruments, but not with others (unless you
rotate the

glasses 90-degrees). Also, these polarized sunglasses
worked fine

with my DG-300 canopy, but created horrible moire &
checkerboard

patterns on a couple of Diamond DA-20 rental aircraft
canopies.



If you're going to fly with a lot of cockpit electronics, I
strongly

recommend against polarized lenses because you don't
want to be

distracted or fumbling with your instruments because of this
effect.

There are plenty of effective non-polarized sunglasses out
there that

give you good visibility and protection.



Lastly, if you're going to be flying in a club or rental
environment,

where you switch ships with any regularity, do NOT assume
that

polarized sunglasses which work in one cockpit will work in
another.



--Noel

Good points.
I guess it all boils down to "it depends". Polarized glasses
always worked
for me in the gliders I flew, but I agree this is not always going
to be
the case.
So the solution is to have a spare non polarized glasses with
you in case
there is an issue.

Ramy

Polarised sunglasses should genarally be expected to have
vertical polarization because the whole point about reducing
glare from water surfaces etc is that the light reflected of the
surface to the eye tends to be polarised horizontally.

On another topic - genuine question - do polarised lenses made
without a UV absorbing tint, and without a UV absorbing lens
material such as polycarbonate, reduce UV transmission more
than in proportion to the reduction in general light
transmission?

John Galloway



re uv absorption by sunglasses with no uv absorbing lens. I have no idea,
but according to the page about my oakleys "...combines patented optics and
PLUTONITE® lens material that provides 100% UV filtering and unsurpassed
impact protection...".

Which is probably of no use to you whatsoever.

All the best.

John Galloway wrote, On 6/14/2013 7:08 AM:

Polarised sunglasses should genarally be expected to have
vertical polarization because the whole point about reducing
glare from water surfaces etc is that the light reflected of the
surface to the eye tends to be polarised horizontally.

On another topic - genuine question - do polarised lenses made
without a UV absorbing tint, and without a UV absorbing lens
material such as polycarbonate, reduce UV transmission more
than in proportion to the reduction in general light
transmission?

Your canopy filters out most of the UVB, as will almost every pair of
sunglasses, regardless of their tint or polarization. Plastic or glass
that passes significant amounts of UVB is "special" stuff that costs
more. UVA transmission is more variable, as it takes some effort to
filter it out, so if you want to block it, look for a pair that
specifically claims to do so.

--
Eric Greenwell - Washington State, USA (change ".netto" to ".us" to
email me)
- "Transponders in Sailplanes - Feb/2010" also ADS-B, PCAS, Flarm
http://tinyurl.com/yb3xywl

After trying a friend's Eagle Eyes (As seen on TV!!!), I found them to
improve detailed vision, especially spotting very thin dust devils. So I
bought a pair with built in readers.

They're great! I used them to take my wife for a ride in a friend's
DG-500m-22 and they were flawless. Yesterday, when I pulled down the canopy
of my LAK-17a, I found the screen of my CAI-302 to be totally black. At
first I thought it was due to the heat but, raising the glasses, I saw the
problem was with the misaligned polarization of the 302 screen with the
glasses.

I wonder if the glass in the 302 can be rotated 40-90 degrees...


"Eric Greenwell" wrote in message
...
John Galloway wrote, On 6/14/2013 7:08 AM:

Polarised sunglasses should genarally be expected to have
vertical polarization because the whole point about reducing
glare from water surfaces etc is that the light reflected of the
surface to the eye tends to be polarised horizontally.

On another topic - genuine question - do polarised lenses made
without a UV absorbing tint, and without a UV absorbing lens
material such as polycarbonate, reduce UV transmission more
than in proportion to the reduction in general light
transmission?

Your canopy filters out most of the UVB, as will almost every pair of
sunglasses, regardless of their tint or polarization. Plastic or glass
that passes significant amounts of UVB is "special" stuff that costs more.
UVA transmission is more variable, as it takes some effort to filter it
out, so if you want to block it, look for a pair that specifically claims
to do so.

--
Eric Greenwell - Washington State, USA (change ".netto" to ".us" to email
me)
- "Transponders in Sailplanes - Feb/2010" also ADS-B, PCAS, Flarm
http://tinyurl.com/yb3xywl

On Sunday, June 16, 2013 9:42:52 AM UTC-7, Dan Marotta wrote:
After trying a friend's Eagle Eyes (As seen on TV!!!), I found them to

improve detailed vision, especially spotting very thin dust devils. So I

bought a pair with built in readers.



They're great! I used them to take my wife for a ride in a friend's

DG-500m-22 and they were flawless. Yesterday, when I pulled down the canopy

of my LAK-17a, I found the screen of my CAI-302 to be totally black. At

first I thought it was due to the heat but, raising the glasses, I saw the

problem was with the misaligned polarization of the 302 screen with the

glasses.



I wonder if the glass in the 302 can be rotated 40-90 degrees...





"Eric Greenwell" wrote in message

...

John Galloway wrote, On 6/14/2013 7:08 AM:



Polarised sunglasses should genarally be expected to have

vertical polarization because the whole point about reducing

glare from water surfaces etc is that the light reflected of the

surface to the eye tends to be polarised horizontally.



On another topic - genuine question - do polarised lenses made

without a UV absorbing tint, and without a UV absorbing lens

material such as polycarbonate, reduce UV transmission more

than in proportion to the reduction in general light

transmission?



Your canopy filters out most of the UVB, as will almost every pair of

sunglasses, regardless of their tint or polarization. Plastic or glass

that passes significant amounts of UVB is "special" stuff that costs more.

UVA transmission is more variable, as it takes some effort to filter it

out, so if you want to block it, look for a pair that specifically claims

to do so.



--

Eric Greenwell - Washington State, USA (change ".netto" to ".us" to email

me)

- "Transponders in Sailplanes - Feb/2010" also ADS-B, PCAS, Flarm

http://tinyurl.com/yb3xywl

No problem with my 302 with all polarized glasses I used. Either your glasses or your 302 polarized wrong.

Ramy

I always fly with my "Zoomies" binocular glasses (as seen on TV) https://www.buyzoomies.com/

Other gliders look 300% closer, so does the ground . . . it's a truly terrifying experience. I have no idea why a wear them but everyone else should as well.

bumper

On Monday, June 17, 2013 1:51:13 PM UTC-7, Ramy wrote:


No problem with my 302 with all polarized glasses I used. Either your glasses or your 302 polarized wrong.



Ramy

Some 302's had their polarization off by 90 degrees (I think they got a bad batch IIRC). When I bought my 302 in '03 screen blacked out with polarized glasses. Sent it in and they replaced the glass to fix this at no charge.

bumper

I don't know of any where to send mine now... I'll just use my older
non-polarized glasses and swap the Eagle Eyes to my car, hiking, and
kayaking.


"bumper" wrote in message
...
On Monday, June 17, 2013 1:51:13 PM UTC-7, Ramy wrote:


No problem with my 302 with all polarized glasses I used. Either your
glasses or your 302 polarized wrong.



Ramy

Some 302's had their polarization off by 90 degrees (I think they got a
bad batch IIRC). When I bought my 302 in '03 screen blacked out with
polarized glasses. Sent it in and they replaced the glass to fix this at
no charge.

bumper