Tablets - not just for PDFs - Page 2

fjtorres · 01-09-2021, 06:51 PM

Quote:

Originally Posted by ottischwenk

There is a difference between looking directly into the light source and seeing reflected light.Yes, but I just take care not to look directly into light sources.

So, no TV?

All forms of TV to date shine light directly at the viewer. CRT, DLP, PLASMA, LCD, and OLED.
In fact, modern flat panels are essentially giant tablets and becoming more so every day.

j.p.s · 01-09-2021, 06:59 PM

Quote:

Originally Posted by fjtorres

So, no TV?

All forms of TV to date shine light directly at the viewer. CRT, DLP, PLASMA, LCD, and OLED.
In fact, modern flat panels are essentially giant tablets and becoming more so every day.

Projector TVs have been around for about 50 years.

(I've never had a projector TV and have no plans to get one.)

DNSB · 01-09-2021, 07:35 PM

Quote:

Originally Posted by j.p.s

Projector TVs have been around for about 50 years.

(I've never had a projector TV and have no plans to get one.)

The last time I looked at a projector TV, the light was bounced off a mirror and onto the back of the screen so much like a backlit LCD display. This is in contrast to using a separate projector bouncing light off the front of the screen

cfrizz · 01-09-2021, 08:32 PM

All of this shows that everyone is different.

I will be turning 60 next month, and as soon as I get my second Moderna shot I'm going to be booking an eye appt to probably spend a ton of money on new glasses for my ever changing eyes.

I have bad eyes, have been wearing glasses since I was two years old, and I have ALWAYS needed/liked lots of light. I exchanged all of my lightbulbs to Daylight, and where tolerated get 100 watt bulbs.

I'm able to read on anything tablet, phone, eink, but my preferred reader is my pc.

Different strokes for different folks.

j.p.s · 01-09-2021, 08:36 PM

Quote:

Originally Posted by DNSB

The last time I looked at a projector TV, the light was bounced off a mirror and onto the back of the screen so much like a backlit LCD display. This is in contrast to using a separate projector bouncing light off the front of the screen

Technically the light is reflected once it is past the mirror

, but it is also much dimmer than just about any conventional CRT or LCD TV screen.

Dropping from about 50 years to 20+ years, LCD projectors with composite video, VGA, or HDMI inputs are TVs (in conjunction with a VCR, DVR, or one of those stick thingies). There even might be some with a tuner built in.

CWatkinsNash · 01-09-2021, 09:31 PM

Quote:

Originally Posted by cfrizz

All of this shows that everyone is different.

I will be turning 60 next month, and as soon as I get my second Moderna shot I'm going to be booking an eye appt to probably spend a ton of money on new glasses for my ever changing eyes.

Oh my gosh yes! I think I'm looking forward to new glasses more than I am being able to finally take a vacation. LOL My astigmatism has this habit of changing drastically (sometimes worse, sometimes better) over the period of several months and then more or less stabilizing for a couple of years or so. And it just so happens that my eyes have gotten quite a bit worse in the past year.

DNSB · 01-09-2021, 09:44 PM

I remember the innocents days of youth when I had single vision glasses. Moved to bifocals and now varifocals with reading glasses for the computer and sunglasses for when I'm driving and don't want to wear my glasses and FitOvers. It probably doesn't help that my eyes have a +5 (or is that -5?) difference in the correction needed between my right and left eyes.

leebase · 01-09-2021, 10:55 PM

Quote:

Originally Posted by ottischwenk

And some people get eye damage, or headaches, or tire faster, or ...
There is a difference between looking directly into the light source and seeing reflected light.Yes, but I just take care not to look directly into light sources.

Yeah...looking at the SUN will hurt your eyes. Looking at the sun reflecting off a mirror -- WILL HURT YOUR EYES.

The advantage of ereaders and paper, is that the reflected light will match the ambient light -- meaning you don't have a huge contrast.

Unless...of course...you are in a light box with huge lamps shining all around you in which case....you are going to have eye problems reading anything.

If you site in a black room, with a very bright reading lamp....you can get eye strain reading off paper....yep...done it many times as a kid.

leebase · 01-09-2021, 10:59 PM

Quote:

Originally Posted by DNSB

I remember the innocents days of youth when I had single vision glasses. Moved to bifocals and now varifocals with reading glasses for the computer and sunglasses for when I'm driving and don't want to wear my glasses and FitOvers. It probably doesn't help that my eyes have a +5 (or is that -5?) difference in the correction needed between my right and left eyes.

I have varifocals as well. I've gone to 2 different sets of reading glasses. One set to the distance for reading in a chair, and the other for the distance from sitting at my desk to the computer monitor.

Varifocals for everything else.

fjtorres · 01-10-2021, 07:14 AM

Quote:

Originally Posted by DNSB

The last time I looked at a projector TV, the light was bounced off a mirror and onto the back of the screen so much like a backlit LCD display. This is in contrast to using a separate projector bouncing light off the front of the screen

Those rear projectors went with the last century.

Some folks do use digital projectors in their home theaters but they're not TVs. No tuners or audio. And they are dimmer than even cheap TVs which is a handicap in the age of HDR, which requires strong zone backlighting or direct emission. It can be done but it gets expensive (mid-four figures) at a time when 70" LCD TVs start at $ 600 or so.

Front projectors are generally meant for computer presentations in corporate meeting rooms but they're starting to be phased out in favor of large touch capable LCD screens like Microsoft's SURFACE HUB, SAMSUNG'S FLIP, and Google's JAMBOARD.

https://medium.com/@vibeus/vibe-vs-g...0whiteboarding.

Those are even more tablet-like than "smart" TVs.

BTW, one thing people forget is that unlike CRTs and Plasma Panels, LCD has polarization layers behind and in front of the LCD layer to prevent glare and make the image brighter. It gets somewhat technical but the bottom line is that LCDs have the equivalent of top quality sunglasses built in so looking at an LCD screen is nothing like looking into an LED flashlight. (Definitely not recommended.)

https://electrosome.com/lcd-display-fundamentals/

Some people might be sensitive to extended viewing of backlit sources but if so they are few and far between and the fault lies within them, not the technology.

Most of the myths about emissive displays come from the early CRTs, which weren't polarized and did produce eye strain. But that ended decades ago. Today's LCD displays are perfectly safe, otherwise people using VR headsets would be going blind all over instead of just getting vestibular headaches.

Quoth · 01-10-2021, 09:55 AM

LCDs don't actually work at all without polarising layers. Nothing to do with glare. The crystal like molecules of the liquid are thread like and have opposite charges, overall neutral, at the ends. Thus with an electric field via transparent electrodes they polarize light. If the rear is fed with polarised light, usually a polarised film on the rear glass, and a second polarising film is on the front glass, then the area between each pair of transparent electrodes, on the inside of front and rear, goes dark or clear as the field is changed. You have to use AC, because DC would cause electrolytic decomposition of the liquid. This is and the back light are the main power loss. The back polariser and lamp can be replaced with a mirror. Or a partial mirror can be between the polariser and glass at the rear.
Colour is achieved by using three dots in line and coloured stripes, or a 2 x 2 pattern of
R G
G B
dots. Or other more complex layouts.
Simple displays use external electronics. Graphics panels above a certain resolution use thin film transistors on part of each dot driving the transparent electrode. The display may be in two halves or four quarters to reduce the duty cycle of the rows and columns. Larger displays have additional multiplexing row and column driver chips on the edges of the glass.

The layers and the polarising aspect of operation limit the viewing angle. Colour shifts due to glass thickness and the wrong filter colour over a dot at shallow angles. The contrast varies with viewing angle, related to thickness of liquid, angle of polarising films, drive voltage and drive waveform.

Even a large display with very few elements that's not using multiplexed drive takes hardly any power, thus a coin cell can run it for a couple of years. The AC nature coupled with multiplexing of millions of dots, x3 to x5 per pixel in colour, dramatically increases the power consumption. But in sunlight, or for a 55" TV in a bright room, most of the power is for the backlight. Due to loss in the polarising filters, colour filters and liquid, a purely reflective colour display needs very bright sunshine. The N9210 Smartphone used CCFL tubes and a high voltage for the backlight, the N9210i later in 2002 used LED backlighting. Even in 2014 a CCFL backlit LCD TV gave better even illumination and colour than edge fed LED backlights on LCDs.

https://en.wikipedia.org/wiki/Liquid..._field_effects
See also https://en.wikipedia.org/wiki/Kerr_effect and https://en.wikipedia.org/wiki/Faraday_effect

Most users of laptops, PC displays, tablets and phones have them far too bright indoors.

Colour CRTs were not an eyestrain issue when properly adjusted. Mono green or Amber or even white CRTs were not an issue if properly adjusted. Other issues were the resolution (either too low on screen or too high on graphics setting), interlace flicker and the wrong viewing distance for regular reading distance glasses. Or people that needed glasses to read refusing to wear them for the computer.

Also today you can't use much more than 17" to 19" with reading glasses at the proper distance without having to move your head. A 21" to 37" screen at reading distance with glasses exceeds the viewing area.

fjtorres · 01-10-2021, 05:05 PM

Quote:

Originally Posted by Quoth

Also today you can't use much more than 17" to 19" with reading glasses at the proper distance without having to move your head. A 21" to 37" screen at reading distance with glasses exceeds the viewing area.

I set my (22-24in) desktop monitors in portrait mode and raise the screen metrics to 150-225 (logical) DPI so I can set the monitor at the ergonomical recommended arm's length viewing distance and avoid eye strain over long distances.

I agree that most people set their screen brightness too high for proper indoor use. Many never bother to adjust from the factory settings which are meant for showroom demos. First thing I do with phones and tablets is take them to minimum and then slowly raise it to a decent contrast. That rarely is even close to half brightness,much less full which is rarely needed even out doors. Maybe at high noon on a sunny day.

(Right now my Fire tablet is running at a bit under 20% of max.)

Quoth · 01-11-2021, 08:51 AM

Oh, and the field of view of reading glasses probably depends on the design and strength, so before buying a larger screen and idea might be to ink a border matching new screen active area on a newspaper and check?

My reading glasses need the object closer than arm's length. Maybe I have long arms. They are for reading books.

Portrait mode of course means a larger screen can be used than say a 16:9 in landscape.

fjtorres · 01-11-2021, 10:26 AM

Quote:

Originally Posted by Quoth

Oh, and the field of view of reading glasses probably depends on the design and strength, so before buying a larger screen and idea might be to ink a border matching new screen active area on a newspaper and check?

My reading glasses need the object closer than arm's length. Maybe I have long arms. They are for reading books.

Portrait mode of course means a larger screen can be used than say a 16:9 in landscape.

More precisely, portrait mode lets a medium screen play like a bigger one. A 22" will be comparable to a 40" for single page wysiwyg. That allows you to boost the metrics.

Playing with the screen metrics will make text and UI elements larger so you can put the monitor further back and still read the text comfortably. It's not just for portrait use, btw.

Back in the CRT days, our AA had a monster 25" high res monitor for graphics that we tweaked the metrics to adjust the field of view for text use at arms length.

Quoth · 01-12-2021, 10:35 AM

Yes. I'm disappointed how few screens can go Portrait. Even fewer laptops.

Seems laptops and monitor screens dominated by the idea of delivering 16:9 landscape made for TV video. I use a 48" screen for video.
Years ago I even occasionally propped CRTs with books to read longer PDF documents full page in a decent font size.

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01-09-2021, 08:32 PM	#19
cfrizz Wizard Posts: 1,570 Karma: 36389706 Join Date: Dec 2009 Location: Quincy, MA Device: Samsung 54A, Kobo Libra H2O, Samsung S6 Lite	All of this shows that everyone is different. I will be turning 60 next month, and as soon as I get my second Moderna shot I'm going to be booking an eye appt to probably spend a ton of money on new glasses for my ever changing eyes. I have bad eyes, have been wearing glasses since I was two years old, and I have ALWAYS needed/liked lots of light. I exchanged all of my lightbulbs to Daylight, and where tolerated get 100 watt bulbs. I'm able to read on anything tablet, phone, eink, but my preferred reader is my pc. Different strokes for different folks.

01-09-2021, 09:44 PM	#22
DNSB Bibliophagist Posts: 46,438 Karma: 169098492 Join Date: Jul 2010 Location: Vancouver Device: Kobo Sage, Libra Colour, Lenovo M8 FHD, Paperwhite 4, Tolino epos	I remember the innocents days of youth when I had single vision glasses. Moved to bifocals and now varifocals with reading glasses for the computer and sunglasses for when I'm driving and don't want to wear my glasses and FitOvers. It probably doesn't help that my eyes have a +5 (or is that -5?) difference in the correction needed between my right and left eyes.

01-10-2021, 09:55 AM	#26
Quoth Still reading Posts: 14,164 Karma: 105212035 Join Date: Jun 2017 Location: Ireland Device: All 4 Kinds: epub eink, Kindle, android eink, NxtPaper	LCDs don't actually work at all without polarising layers. Nothing to do with glare. The crystal like molecules of the liquid are thread like and have opposite charges, overall neutral, at the ends. Thus with an electric field via transparent electrodes they polarize light. If the rear is fed with polarised light, usually a polarised film on the rear glass, and a second polarising film is on the front glass, then the area between each pair of transparent electrodes, on the inside of front and rear, goes dark or clear as the field is changed. You have to use AC, because DC would cause electrolytic decomposition of the liquid. This is and the back light are the main power loss. The back polariser and lamp can be replaced with a mirror. Or a partial mirror can be between the polariser and glass at the rear. Colour is achieved by using three dots in line and coloured stripes, or a 2 x 2 pattern of R G G B dots. Or other more complex layouts. Simple displays use external electronics. Graphics panels above a certain resolution use thin film transistors on part of each dot driving the transparent electrode. The display may be in two halves or four quarters to reduce the duty cycle of the rows and columns. Larger displays have additional multiplexing row and column driver chips on the edges of the glass. The layers and the polarising aspect of operation limit the viewing angle. Colour shifts due to glass thickness and the wrong filter colour over a dot at shallow angles. The contrast varies with viewing angle, related to thickness of liquid, angle of polarising films, drive voltage and drive waveform. Even a large display with very few elements that's not using multiplexed drive takes hardly any power, thus a coin cell can run it for a couple of years. The AC nature coupled with multiplexing of millions of dots, x3 to x5 per pixel in colour, dramatically increases the power consumption. But in sunlight, or for a 55" TV in a bright room, most of the power is for the backlight. Due to loss in the polarising filters, colour filters and liquid, a purely reflective colour display needs very bright sunshine. The N9210 Smartphone used CCFL tubes and a high voltage for the backlight, the N9210i later in 2002 used LED backlighting. Even in 2014 a CCFL backlit LCD TV gave better even illumination and colour than edge fed LED backlights on LCDs. https://en.wikipedia.org/wiki/Liquid..._field_effects See also https://en.wikipedia.org/wiki/Kerr_effect and https://en.wikipedia.org/wiki/Faraday_effect Most users of laptops, PC displays, tablets and phones have them far too bright indoors. Colour CRTs were not an eyestrain issue when properly adjusted. Mono green or Amber or even white CRTs were not an issue if properly adjusted. Other issues were the resolution (either too low on screen or too high on graphics setting), interlace flicker and the wrong viewing distance for regular reading distance glasses. Or people that needed glasses to read refusing to wear them for the computer. Also today you can't use much more than 17" to 19" with reading glasses at the proper distance without having to move your head. A 21" to 37" screen at reading distance with glasses exceeds the viewing area.

01-11-2021, 08:51 AM	#28
Quoth Still reading Posts: 14,164 Karma: 105212035 Join Date: Jun 2017 Location: Ireland Device: All 4 Kinds: epub eink, Kindle, android eink, NxtPaper	Oh, and the field of view of reading glasses probably depends on the design and strength, so before buying a larger screen and idea might be to ink a border matching new screen active area on a newspaper and check? My reading glasses need the object closer than arm's length. Maybe I have long arms. They are for reading books. Portrait mode of course means a larger screen can be used than say a 16:9 in landscape.

01-12-2021, 10:35 AM	#30
Quoth Still reading Posts: 14,164 Karma: 105212035 Join Date: Jun 2017 Location: Ireland Device: All 4 Kinds: epub eink, Kindle, android eink, NxtPaper	Yes. I'm disappointed how few screens can go Portrait. Even fewer laptops. Seems laptops and monitor screens dominated by the idea of delivering 16:9 landscape made for TV video. I use a 48" screen for video. Years ago I even occasionally propped CRTs with books to read longer PDF documents full page in a decent font size.

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