polarized lenses lcd displays quotation

Just tried out a fix for the black-out + polarized glasses problem with the a7iii, i.e. putting on a protective glass on the screen. And voila, it works, to some extend.

The screen is now fully visible, but as with many other things and polarized glasses, the tint of the screen changes with rotation. My suspistion is that the adhesive between the glass and screen diffracts the light from the display to become more scattered (less polarized) thus allowing various colors and light to get through the polarization of the sunglasses.

Might explain why most smartphone screens tend to be reasonably visible (as in, you see visual artifacts but at least it"s not pitch black) with polarized glasses.  Or smartphone manufacturers have taken this phenomenon into account and include QWPs by default.

The A7M3 is the only product I"ve used that went pitch black with my prescription polarized glasses.  To the point where the first time I took it out when wearing the glasses, I thought the camera was broken.

Turns out that my current phone has an AMOLED not LCD, I could have sworn otherwise, but I"ve definitely had OK results with my glasses and other LCDs.

Polarized sunglasses may make it easier and more comfortable to see outdoors, but wearing them while trying to read an LCD (liquid-crystal display) screen can sometimes — literally — leave your eyes in the dark.

Most LCDs, such as your smartphone and tablet, use a polarizing filter to help you see the screen in bright sunlight. But so do polarized sunglasses, meaning the two essentially cancel each other out, causing your LCD screen to appear dark or completely black when you look at it.

Polarized sunglasses are designed to block glare — overly bright light reflected off shiny surfaces such as water and snow. Natural light consists of protons bouncing in many directions; polarized lenses filter that light, causing those protons to travel in a single, uniform direction (usually horizontal).

Polarized sunglass lenses are coated with a chemical compound composed of molecules that are parallel to one another. These molecules absorb any light waves traveling in the direction in which they’re aligned, preventing them from passing through the coating.

LCD screens and sunglasses typically contain a polarizing filter for the same reason: to make it easier for you to see clearly, especially in bright sunlight.

What tends to happen is your polarized sunglasses do their job by only allowing light to pass through vertically. Meanwhile, your phone screen emits horizontally vibrating light while blocking vertical light.

Your lenses and screen end up counteracting each other by working in opposite directions. As a result, you wind up seeing a dark or blacked-out image.

The solution is simple: Rotate your tablet or phone screen by 90 degrees. This trick usually works because it positions your screen’s polarizing filters so they block light waves traveling in the same direction as your polarized sunglasses, allowing light to pass through.

Newer smartphone and computer screens have found ways to compensate for this issue, but you may still notice a darker screen when wearing polarized sunglasses with an older model screen.

In some cases, you may need to view LCDs on an instrument panel that can’t be rotated. This can be true for boaters and pilots who must be able to read instrumentation quickly and accurately to ensure their safety. For this reason, you should avoid wearing polarized sunglasses in these circumstances.

Polarized lenses also can interfere with your ability to see and read the displays on gas pumps and ATMs. To see more clearly when filling your tank or withdrawing money, remove your sunglasses when performing these tasks.

Any reputable eyewear retailer (brick-and-mortar store or online shop) will provide accurate labeling on sunglasses they offer, so you should be able to tell at a glance whether those sunglasses you’re considering have polarized lenses.

Hold the sunglasses in a way that allows you to look through both pairs of lenses at the same time. Rotate one pair of sunglasses by 90 degrees. If all light is blocked when passing through both pairs, then your older sunglasses probably have polarized lenses.

You also can test your sunglasses by looking at an LCD screen while wearing them. Just remember to rotate the device 90 degrees to make sure you’re checking for a polarizing filter that blocks light traveling either horizontally or vertically.

ARE YOUR SUNGLASSES POLARIZED? If not, it might be time for a new pair. Shop for polarized sunglasses at an optical store near you or an online eyewear retailer

Warning: Science Content
Not technically asked for, but I"m waiting for a simulation to finish, and I"m bored:

Why polarizing sunglasses appear different:
When light reflects off of a partially transparent surface, like water or glass, the reflected rays are polarized in the direction parallel to the surface. The perpendicular polarization is transmitted through the surface. Polarizing sunglasses take advantage of this phenomena by setting the direction of polarization to be vertical. Since most outdoor reflecting surfaces will be horizontal or near-horizontal, that means the reflected light (glare) is blocked.

Why polarizing lenses don"t always work with LCD displays
A liquid crystal cell uses polarization to switch on or off. Generally, the cell consists of two perpendicular polarizers separated by a region of liquid crystal. When the liquid crystal is switched "on" it rotates the polarization of light passing through it by 90 degrees. So, the backlight passes through the first polarizer, rotates 90 degrees and then passes through the second, perpendicular polarizer.

As a consequence the light coming out of an LCD display is polarized. If the polarization of the LCD is perpendicular to the polarization of your sunglasses, then you will not be able to read the LCD. Most LCDs these days are getting smarter about this, though. Since polarized sunglasses have vertical polarizations, LCD manufacturers simply orient their output polarizers the same way, and then there is no issue. More realistically, they tend to output at 45 degrees. That way, no matter how the rectangular screen is oriented, some of the light will pass through the sunglasses lens. The contrast will be reduced, but it will probably still be readable.

If that"s not the case, the simple solution, as noted above, is for the person wearing the polarized lenses to simply tilt their head to the side. The further you tilt, the more readable the display should become.

Incidentally, I doubt I will ever buy a pair of sunglasses that aren"t polarized. With my last pair of (prescription) sunglasses, I actually had to fight to get them to polarize them, but it was totally worth it.

I have found throughout my many years in this industry that many patients still do not have a clear understanding of the difference between a tinted and a polarized sunglass. So, the big question you’re probably asking yourself is, “why do I want over another?”

Polarized lenses are created in a completely different fashion. There is actually a film sandwiched inside the clear lens (for most versions of polarized…see Maui Jim below). This film is actually made of thousands of microscopic lines packed so closely together they give the appearance of color. These lines are placed so closely together to handle the glare.

Polarized lens technology takes advantage of the wave nature of light. When light reaches us from the sun, it folows a unifom wave pattern, wherein all the light is in phase–that is to say all the wavelengths of light are in the same plane. When the light hits a surface, it scatters in multiples angles, creating the flare of glare.  This is where the polarized film in your sunglasses comes in.  All those lines, packed so tightly together, prevent all the scattered light from passing through the lens.  Only the original wavelengths, continuing in their original straight path, are let through.  This dramatically reduced the reflected glare and increases visual comfort, even on a lens with less tint.

Sounds great right?  You must be asking yourself, “Whats the catch?” Well, I wouldn’t call it a catch, but there are a couple of things to be aware of with polarized lenses.  LCD displays use polarized film to work.  When two polarizing films are set 90 degrees apart, all visibility is blacked out.  So this means, if you look at a digital calculator, as an example, it could be black and impossible to see any image displayed.  This is rare, and can be fixed by tilting your head slightly.  In my experience, there can be issues with clarity on the LCD displays for some cars (i.e. BMW’s from the early 2000’s).  This can include your odometer or even your GPS navigation system.  Pretty much all smart phones post version 5 (iPhone, Galaxy) this is a non issue.  But the older devices can have a soap bubble appearance.

For the vast majority of patients, Polarized lenses will be more comfortable and functional. But there are some lifestyles, and work environments where polarized lenses don’t make a lot of sense.

Pilots: you’d think this was a perfect case for polarized making sense, but the Shatter resistant windscreens of planes can create tremendous rainbow distortions which are only clearly visible when looking through a polarized lens.

Photographers:  The viewfinder on most SLR and DSLR cameras are LCD, which can have terrible rainbow distortions when viewed through a polarized lens (think of the earlier example of soap bubbles).

Maui Jim polarized lenses are a little different in that their polarizing film is fused directly into the lens so delamination is a non-issue and colors are enhanced in a substantial way.  I have worn polarized lenses from at least a half dozen lens manufacturers and I always fall back on Maui Jim’s as my go-to pair–even when the prescription is out of date.

Polarized lenses dramatically reduced your perception of reflected light/glare while wearing them.  The technology does allow you to see chromatic structures and other things not normally visible with the naked eye.  This is less of a problem, than something to be aware of, and to know how to get around it.  While polarized lenses make the most sense for most patients, there are subsets of the population where polarized just doesn’t make sense, such as photographers and pilots.

This study achieves real-color displays using a randomizing effect based on the concept of “natural light.” At present, most displays emit linearly polarized light, which causes essential blackout and color degradation problems when the displays are viewed through polarizers such as sunglasses. To address this, complex polarization-control technologies are added to existing displays, but the problems remain unresolved. In contrast, this study randomizes the polarization using a polymer film called a random depolarization film (RDF) that is doped with specific birefringent crystal particles. The RDF placed on a display reproduces colors that are very close to the natural colors seen in reality without the need for complex polarization technologies. We believe that it has the potential to change the approach to color-reproducing technology for displays.