Night mode reading preference vs normal mode

[ProDigit]

I've done a few tests on Night mode readability vs day mode, and when it's best to use them

I put it in a small chart:



There are 3 environmental settings, and 3 illumination settings.

The environmental settings are:
1- Bright (outside)
2- Office (~300-500nits)
3- Night/dark (bedroom at night)

The illumination settings are:
1- Back light (either light mounted behind, or inside the display)
2- Front light (light either mounted on top of the display, or as an outside light shining on the screen)
3- Natural light (environmental light)

There are 4 possible results:
1- Night = night mode; dark screen white text
2- Normal = day mode; white screen black text
3- Both, could be seen as 'either'
4- X = not a viable way to read


In my tests I found that in outside (bright) light, it's MUCH better for the eyes to use Night mode in ALL 3 illumination settings.
The outside light (sun) is overpowering most back or front settings, and reading a white page in a bright sun is hurting the eyes.

In all Office light scenarios, it was a matter of preference, with a front light having a slight edge on normal mode (as night mode blocks out too much light from front lit screens, and may make the text harder to read in night mode).


In all dark room (night) environments,
The natural light was not an option, as one couldn't read an ereader with some illumination (and at night ambient light is close to zero).
The front light, same as the office setting, preference set to normal mode, as night mode bleeds out the light, and makes text harder to read.
The back light, was a matter of preference. While both were very close to one another in terms of readability, the night mode had a slight edge for me due to there being less light bleed, possibly bothering a partner sleeping next to you when reading in bed.

Those are my personal preferences.

[Paperbackstash]

Hm, interesting. You've put a lot of thought into this.

[Dazrin]

Can you explain your testing a little more.

Did you use 2 or 3 different devices to test the lighting? There is no single device that I know of that can function with all three lighting modes you describe. This would be more useful if you provide some details on the device(s) used for testing.

I assume:
Back - LCD or OLED screen with a backlight or integral light.
Front - e-ink with a front light (Kindle Paperwhite, Kobo Clara HD or similar)
Natural - e-ink with front light disabled (or not present)

Can you confirm what devices you actually used?

[Quoth]

Anyone needing black background and white text simply has a backlight (LCD) or front light (eink) or brightness (OLED) too high, or if eink with no built in light they have a terrible reading light unsuitable for paper books.

The LCD and OLED screens are very different.
LCD uses rear lighting that can be LED, or on old things 18 years ago, CCFL. LCD lighting can be using an array behind a diffuser (big quality TVS) or lighting at the edge of a rear light pipe. LCDs need two polarisers, one front and back and need coloured dye filters as they are monochrome. The quality of the white backlight depends on the LEDs. Only very expensive TVs use Red, Green and Blue LEDs. Older TVs, Laptops and early smartphones used CCFL tubes which can have better phosphors because the tube emits a mix of UVA and UVB. White LEDs do not exist. They are blue, violet or near UV LEDs with mostly a broad spectrum yellow phosphor. They vary hugely in colour temperature and colour rendition.

The various kinds of OLED displays are not real LEDs in the sense of backlights, indicators or ancient calculators. They are electroluminescent dots that are diode like. They usually have phosphors as they don't properly do red and green. They might have filters on the front glass too.

An amber screen filter may work better for LCD and OLED it's too blue at night. The software approach is poor.

So called Dark mode was invented because of people simply having too high a brightness setting on LCD and OLED. It's actually more tiring than white background with proper brightness and ambient light.

[DiapDealer]

Dark environment: dimmer backlight.
Bright environment: brighter backlight.

My brightness slider is rarely higher than 30%. Ever.

I use a slightly off-white background 100% of the time. Never light text on a dark background for book-reading.

I have zero issues reading in either well-lit or totally unlit environments. I don't read outdoors. I can overthink this all of this, or I can just read. I choose the latter.

[Sirtel]

I never use the night mode either, on LCD or eink. It's just not comfortable for my eyes. If the room is very dimly lit and the screen brightness won't go low enough (my new Dell laptop has such a drawback), there are many dimmer apps, both for Android and Windows. Add the warm light option which all my actively used devices have, and it's possible to get a comfortable screen background for reading or working without using the night mode.

YMMV, obviously.

[4691mls]

One reason I've seen given for using night mode is to make the screen as dark as possible so as not to disturb a bed partner who is trying to sleep.

There are also some people who simply prefer the appearance of light text on a dark background.

I live alone and don't like the appearance of white text on a black background so I don't use night mode.

[ProDigit]

Originally Posted by Dazrin

Can you explain your testing a little more.

Did you use 2 or 3 different devices to test the lighting? There is no single device that I know of that can function with all three lighting modes you describe. This would be more useful if you provide some details on the device(s) used for testing.

I assume:
Back - LCD or OLED screen with a backlight or integral light.
Front - e-ink with a front light (Kindle Paperwhite, Kobo Clara HD or similar)
Natural - e-ink with front light disabled (or not present)

Can you confirm what devices you actually used?

All devices are E-ink devices.
The backlight, like mentioned are your standard e-ink with built in led.
The front light, is more like a Sony PRS-700 with front light, or popup light (a bulb right above the screen, or a click on magnifying glass with led.
Natural light is no back/front light, and only using environment light, like a spot, room light, night light, or open curtain windows shining daylight into the room.

[ProDigit]

Originally Posted by Quoth

Anyone needing black background and white text simply has a backlight (LCD) or front light (eink) or brightness (OLED) too high, or if eink with no built in light they have a terrible reading light unsuitable for paper books.

The LCD and OLED screens are very different.
LCD uses rear lighting that can be LED, or on old things 18 years ago, CCFL. LCD lighting can be using an array behind a diffuser (big quality TVS) or lighting at the edge of a rear light pipe. LCDs need two polarisers, one front and back and need coloured dye filters as they are monochrome. The quality of the white backlight depends on the LEDs. Only very expensive TVs use Red, Green and Blue LEDs. Older TVs, Laptops and early smartphones used CCFL tubes which can have better phosphors because the tube emits a mix of UVA and UVB. White LEDs do not exist. They are blue, violet or near UV LEDs with mostly a broad spectrum yellow phosphor. They vary hugely in colour temperature and colour rendition.

The various kinds of OLED displays are not real LEDs in the sense of backlights, indicators or ancient calculators. They are electroluminescent dots that are diode like. They usually have phosphors as they don't properly do red and green. They might have filters on the front glass too.

An amber screen filter may work better for LCD and OLED it's too blue at night. The software approach is poor.

So called Dark mode was invented because of people simply having too high a brightness setting on LCD and OLED. It's actually more tiring than white background with proper brightness and ambient light.

Not really true.
There are 2 scenarios where Night mode makes sense:
1- Using e-ink books in normal day mode (same like reading a book) in bright outside sunlight, is very damaging to the eyes.
There is too much light hitting your eyes, and may cause temporal blindness.
For that matter, when you have a high intensity light source, it's better to use night mode.

2- In a totally dark room, with the darkest backlight setting (or built in light like most Kindle Paperwhites and Oasis devices), the device emanates much more light bleed in normal mode than in night mode.
Only in these back light devices (or kindle-like front light how they like to call this here; though in a sense it's not a popup or PRS-700 kind of front light),does night mode make sense.
Meaning, the light emanating might lit up the room behind you in normal mode, will no longer do that in dark mode.
My tests also found the text is just as readable in night or day mode in a dark room.
Not so much with a PRS-700, where the front light bleeds out in night mode, and where letters are harder to read in night mode than day mode.
Though it's really a matter of personal preference. For as long as you can read the text on a front lit (popup led) display, you can choose either one.

Most of my tests were done with very small text (below 10pt) to aggravate or stress the reading more than with bigger fonts.
So my preferences probably won't bother others as much, who use larger fonts or displays.

[ProDigit]

Personally I like white on black text. It reads just as good, if not better in some cases.
Though where you use the E-ink devices most, will be in office or dark rooms.
Both of which don't really favor night mode reading.

[DNSB]

Originally Posted by ProDigit

Not really true.
There are 2 scenarios where Night mode makes sense:
1- Using e-ink books in normal day mode (same like reading a book) in bright outside sunlight, is very damaging to the eyes.
There is too much light hitting your eyes, and may cause temporal blindness.
For that matter, when you have a high intensity light source, it's better to use night mode.

Do you have any links to studies supporting your statement? The closest I can were lists of urban myths about reading which included reading in daylight. One sample is quoted below.

Below we debunk some of the most common myths related to reading and vision:

Reading in low light or in the dark will weaken your eyesight – When we’re young we’re told not to read in the dark because it will damage our eyes. Well, for those of us that used to hide under the blankets with a flashlight, it may have caused minor eye strain, but no permanent damage.

Reading while wearing glasses will make your eyes more dependent on them – Because you’re getting used to seeing more clearly while wearing eyeglasses or contacts, it may make your vision seem worse when you’re not wearing them. But rest assured, it has no negative effect on your eyesight.

Reading in direct sunlight can be dangerous – Any activity done in the sunlight can cause UV damage. Be sure to wear UV-blocking sunglasses and a wide-brimmed hat.

Reading smaller print can damage your eyes or wear them out – Though reading in a fine print may cause eye strain, there is no evidence that doing so will damage the eyes. If eye strain’s got you down, try purchasing books with larger print, or using a digital tool, such as a tablet or e-reader that allows you to change the font size. (But if you are reading on a digital device, make sure you’re following the 20/20/20 rule for screen use!)

You will notice that they cautioned about UV from daylight but that reading in daylight is innately damaging to your eyes is an urban myth. Perhaps you are thinking about photokeratitis aka snow blindness when your corneas get sunburned. Often associated with snow since snow does reflect up to 85% of incident UV. Also know to welders as flash blindness.

BTW, thanks for the chuckle when I read "temporal blindness".

[Quoth]

Originally Posted by ProDigit

Not really true.
There are 2 scenarios where Night mode makes sense:
1- Using e-ink books in normal day mode (same like reading a book) in bright outside sunlight, is very damaging to the eyes.
There is too much light hitting your eyes, and may cause temporal blindness.
For that matter, when you have a high intensity light source, it's better to use night mode.

If it's THAT bright outdoors you need sunglasses to cut down UV.
In general there is no reason to use night mode on LCD, OLED or eink.

Originally Posted by ProDigit

2- In a totally dark room, with the darkest backlight setting (or built in light like most Kindle Paperwhites and Oasis devices), the device emanates much more light bleed in normal mode than in night mode.

Get a 3W to 5W filament style LED bulb in a reading lamp, or a 40W Halogen. A silvered reflector Par lamp in a shielded lamp that can be angled is best.
Any lighting good enough to read a 40 yo paperback is more than good enough. Turn off the eink front light. I have my Lenovo 10" tablet at about 5% to have same brightness as paper at night reading.

I've found the front light on eink on PW3, Original H2O or Libra is even enough to read in those situations where there isn't enough light. About 10% max. No need for white text on black.

The inverse or dark modes were invented for cheap nasty screens that had too high a minimum brightness. I've not seen such poor LCDs made in the last 15 years.

It wasn't a problem on my 2000 or 2002 laptops.

No-one needs dark / inverse mode. It's actually often more tiring. Simply setting screen brightness or ambient lighting is more important.

I did actually wear sunglasses to read on occasion even here in Ireland outside, both paper and eink.
The phone, tablet and laptop are all pretty useless in full sunlight and inverse white text on black doesn't fix it.

[Quoth]

My 90 year old dad does use the front light, so as to read under the bed clothes.
As a kid they had no electricity till he was about 9. Though it was a city.

[Quoth]

Originally Posted by DNSB

You will notice that they cautioned about UV from daylight but that reading in daylight is innately damaging to your eyes is an urban myth.

Spot on. Even not reading but being in bright urban paint/concrete / beach / snow there is too much UV.

Sunglasses and sunblock.

[Sirtel]

Originally Posted by Quoth

The inverse or dark modes were invented for cheap nasty screens that had too high a minimum brightness. I've not seen such poor LCDs made in the last 15 years.

It's not only cheap screens. My new Dell laptop is top-of-the-line, and it has very high minimum brightness. All my previous laptops and tablets (even very cheap ones) had the backlight go much lower. Still, I use the combination of a dimmer app plus warm light in a dim room, instead of a night mode, which I don't like.