Polaroids and LCD screens

[Pete735]

Bear with me on this, but I am hoping someone can throw some "light" on this.

I picked up my new glasses from Specsavers this week and asked if they could sort out a pair of clip on/flip up polaroids for me, to enable me to use them when sailing, but still be able to see lcd screens by flipping the polaroids out of the way temporarily.

I have a pair of £3.99 "polarised" sunglasses bought from Aldi last year. Curiously I can read my Samsung phone, my brand new Lenovo tablet and a 10 year old flat computer screen perfectly.

I went down to Specsavers this morning to see the collection of polarised clip on/flip ups they had got hold of for me to look at. I also took my Aldi sunglasses to ask them to check if they were polarised as according to many posts on here, if they were polarised I should find it difficult to read lcd screens.

They confirmed that the Aldi sunglasses were polarised. So my confusion is; has technology moved on and is this no longer an issue or are there different types of lcd screens or indeed are none of the screens I have checked actually lcd screens.

I am really rather confused and from previous posts on this subject I know that there are a couple of formites who seem to have some optical experience. Just wondered if there was an explanation or most likely, have I completely misunderstood something.

 

[Plum]

My wife got polaroid sunglasses only to find the Nexus tablet i use as a chart plotter appeared black unless she tipped her head to one side or i remounted the tablet in portrait format. We compromised,she now keeps an old pair of non polorised sunglasses on board.

Www.solocoastalsailing.co.uk

 

[rob2]

It all depends which way the polarisation is oriented. Just as the tablet becomes readable when turned through 90 degrees, so devices may be OK or need to be rotated. The polarisation of the glasses is horizontal to eliminate glare from reflected light off the sea. If you have two polarized lenses you can demonstrate the effect by olding one in front of the other and rotating one of them. Crossed polars are almost opaque.

Rob.

 

[Alpha22]

You can also get circular polarisation......

 

[johnalison]

You can also get circular polarisation......

Now you're being confusing. I've only used a circular polariser on an autofocus camera to allow the autofocus to work properly. My sunglasses are polarised and my instrument display appears to be polarised at 45 degrees, with one later addition being at 90 degrees to the other.

 

[Chalker]

When you spec a custom LCD for a piece of equipment you get to choose the polarisation. Some go for 45 degs so that normal polarised sunglasses only dim the display rather than blanking it out. But why do they not spec them at O degs? Wish that I could remember!

 

[Bru]

When you spec a custom LCD for a piece of equipment you get to choose the polarisation. Some go for 45 degs so that normal polarised sunglasses only dim the display rather than blanking it out. But why do they not spec them at O degs? Wish that I could remember!

It's to do with optimising the viewing angle. Don't ask me to explain 'cos I don't pretend to understand why (!)