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iPad screen darkens in portrait orientation/polarized sunglasses

I

important

macrumors member
Original poster
Jul 13, 2009
30
0
This is going to sound strange, but...I use my iPad a lot during my commute to the office, and noticed that when I am wearing polarized sunglasses, I can read the iPad screen in landscape orientation, but as soon as I turn it to portrait, the screen darkens to point where I can't really see anything. This effect goes away when I take my sunglasses off.

Can anyone else confirm they have this issue, or do I need to be checked for some sort of "vertical orientation blindness?"
 
important said:
This is going to sound strange, but...I use my iPad a lot during my commute to the office, and noticed that when I am wearing polarized sunglasses, I can read the iPad screen in landscape orientation, but as soon as I turn it to portrait, the screen darkens to point where I can't really see anything. This effect goes away when I take my sunglasses off.

Can anyone else confirm they have this issue, or do I need to be checked for some sort of "vertical orientation blindness?"
Click to expand...

It's the coating on your sunglasses. Same thing happens when I have on my polarized sunglasses and try to use my iPhone at certain angles.
 
Happens with any LCD screen. One of the layers in an LCD is a polarizing filter. When you rotate the screen so its polarizing layer is at 90 degrees to the polarizing filter in your glasses, it blocks all light.
 
Yup. Happens on both my iPad and iPhone. At some angles my iPhone is almost impossible to read in landscape mode while wearing polarized glasses.
 
DVDxR said:
Happens with any LCD screen. One of the layers in an LCD is a polarizing filter. When you rotate the screen so its polarizing layer is at 90 degrees to the polarizing filter in your glasses, it blocks all light.
Click to expand...

Thank you. That explains it for me. I've wondered about the why and how, but kept forgetting to look it up. Cool
 
Slightly off topic, but just wanted to point out that this is the same effect that they use in modern 3D movies. They project two images onto the screen that have slightly different perspectives. One is in left polarization, one is in right. The glasses you wear are also polarized; one only passes left polarization, one only passes right. Your eyes then see two different images, and your brain combines them to make a 3D image. Cool stuff! :D
 
It's nt a coating on your sunglasses, it's your sunglasses. Polarized sunglasses only let light through that is oriented in one direction. The coating is on the iPad.
 
Blorzoga said:
It's nt a coating on your sunglasses, it's your sunglasses. Polarized sunglasses only let light through that is oriented in one direction. The coating is on the iPad.
Click to expand...

It's not a coating - it is an actual filter that is part of the screens construction. If you pull apart any device with an LCD (for example an old calculator) there is a polarising filter usually made of plastic that lies on top of the LCD. If you remove that off the display then you will no longer be able to see anything, and when rotated your calculater has white numbers on a black background (pretty cool IMHO).
 
It's your sunglasses

It's normal for polarized sunglasses to do that.
If you use an antiglare filter on your iPad, you may not need to take off your sunglasses. Give it a try first.
 
The Power Support non-glare screen protector will fix this. Seriously.

Dunno about the glossy one. I have the non-glare.

This will occur with most any IPS display. I say "most any" because it does NOT affect iPhone 4. But it does affect my iPad and my Samsung SyncMaster monitors.

(OK, on iPhone 4, there is a color shift between orientations, but it doesn't black-out like the iPad.)
 
Same thing happens when I try to fill up my gas tank at a local Sunoco. Can't read the electronic screen on the gas pump with my sunglasses.
 
WHat you are experiencing is normal.

I have an LCD display on my motorcycle and when I wear Polarized Sunglasses it too goes dark.

I no longer wear polarized sunglasses when riding.

If I get an iPad, I'll know not to wear them when using it either.

( actually my son had an iPad mounted on his motorcycle and he told me about the issue. )
 
jtara said:
The Power Support non-glare screen protector will fix this. Seriously.

Dunno about the glossy one. I have the non-glare.

This will occur with most any IPS display. I say "most any" because it does NOT affect iPhone 4. But it does affect my iPad and my Samsung SyncMaster monitors.

(OK, on iPhone 4, there is a color shift between orientations, but it doesn't black-out like the iPad.)
Click to expand...

How? This happens as the the polarization of the sunglasses and that of the LCD approach 90 degrees to one another, at which point the polarized light from the LCD is blocked by the polarized lens. I don't see how a cover will negate the polarization of the LCD.
 
JohnArtist said:
Same thing happens when I try to fill up my gas tank at a local Sunoco. Can't read the electronic screen on the gas pump with my sunglasses.
Click to expand...

I think I need to make you aware of the danger associated with Polarized sunnies. The problem is that you may not recognize wet patches on the road because the polarized lenses remove the tell-tale glare. This is more of a concern for those of us on two wheels - motorized or not - but is still dangerous nonetheless.
 
Full of Win said:
How? This happens as the the polarization of the sunglasses and that of the LCD approach 90 degrees to one another, at which point the polarized light from the LCD is blocked by the polarized lens. I don't see how a cover will negate the polarization of the LCD.
Click to expand...

Unless the polarisation filter on the cover changes the orientation of the light coming through the filter on the iPad so it is no longer at 90 degrees to the filter on the glasses when looked at in portrait. The screen would still appear darker though.
 
Ciclismo said:
I think I need to make you aware of the danger associated with Polarized sunnies. The problem is that you may not recognize wet patches on the road because the polarized lenses remove the tell-tale glare. This is more of a concern for those of us on two wheels - motorized or not - but is still dangerous nonetheless.
Click to expand...

You beat me to it. Good post.
 
Ciclismo said:
I think I need to make you aware of the danger associated with Polarized sunnies. The problem is that you may not recognize wet patches on the road because the polarized lenses remove the tell-tale glare. This is more of a concern for those of us on two wheels - motorized or not - but is still dangerous nonetheless.
Click to expand...

Uh, they are supposed to remove the glare, so you can actually see the road in blinding sunlight.

I have been wearing polarized sunglasses as long as I have been driving, over 30 years now, and I can say without hesitation that I would much rather have polarized glasses than not. I can easily recognize water on the road, and I don't have to deal with blinding glare that in some situations can keep me from seeing the road and oncoming traffic.

Depending on the angle of the sun, polarized glasses can also help cut through fog and haze.
 
So the reason the iPhone 4 isn't affected is because they have rotated the polarizing filter to make it so in both portrait and landscape you do not see it. On the very first iPhone it had the issue in one orientation, on the 3G it was fixed, and now on the iPad the problem is back. The screen is indeed polarized, they just didn't take the time to rotate it to a position where it wouldn't be an issue. My guess is that on the next version they will rotate it to fix the issue.

I used to do quite a lot of work with polarizing film and lenses when I worked with Oakley on their sunglass lenses for 5 years.

Here is a picture of a set of lens blanks from a mold I designed for them a few years back. In it you can see the polarized wafers. They are purposely cut with flat side and two little tabs at the bottom to insure they always go in the mold the same way before they are over-molded with the polycarbonate plastic:

4847001070_6d0227a2da_b.jpg


These blanks are the put into a machine where the outside shape of all different sorts of lenses are cut then put into their different frames.
 
Ciclismo said:
I think I need to make you aware of the danger associated with Polarized sunnies. The problem is that you may not recognize wet patches on the road because the polarized lenses remove the tell-tale glare. This is more of a concern for those of us on two wheels - motorized or not - but is still dangerous nonetheless.
Click to expand...


No where near as dangerous as the constant UV getting into your eyes with non-polarized glasses.
 
There are a few stories about people going to the Genius Bar because the 'screen won't turn on' then when they go inside and take off their glasses its fine. Funny phenomenon.
 
ntrigue said:
There are a few stories about people going to the Genius Bar because the 'screen won't turn on' then when they go inside and take off their glasses its fine. Funny phenomenon.
Click to expand...

While on vacation a couple weeks ago i decided to pull out the ipad and launch the maps app. I couldn't get the screen to come on. Very odd. As I rotated the screen from portrait to landscape mode to do a reset, the screen slowly came back on. Polarized? Took off my glasses, and all was right with the world. I never noticed this polarizing issue before, as 99% of the time I use the iPad in landscape mode.
 
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