Anyone tried or considering NXTPAPER 4.0 devices?

[Kbobnook]

It seems to bridge longer battery life with an e-inlnlike mode and regular LCD tablet modes. 11 inch android tablet for $250 isn't the cheapest price, and it's not flagship processor or anything, but always look for something easier on the eyes.

There's also a 14" tablet and a 6.8" 5g phone using the same screen tech.

[Quoth]

The Nxtpaper 2.0 and 3.0 models are fine for reading. The mono eink is only better under ambient light with frontlight off. The default settings are not the best. sRGB, adjust colour balance and only have auto brightness outdoors. Turn down brightness a lot indoors. Far superior to color eink for relaxed reading and no eyestrain.

The eink simulations (mono and color) do make Nxtpaper 2.0 or 3.0 look more like eink with a front light on. They are inferior to simply properly adjusting sRGB mode colour balance and screen brightness. A marketing gimick.

My Nxtpaper 11 (not pro) has comparable battery life to some eink and the Nxtpaper 40 4G phone and Nxtpaper 14 are pretty good. Note that the 14 is 14.25″ and 3:2 aspect, so practically twice the area of a 10.3" eink. First portable device I've ever had that's good for all PDFs. I ditched the reMarkable and Elipsa (both 10.3″ eink).

I read novels on the 8″ Kobo Sage without front light due to handy size for me. I have also 5, 6, 6.8, 7 and 7.8 eink. It's a pity there isn't an 8″ 4:3 Nxtpaper, but really reflowable novels don't need colour and 14.25″ is far a better size for coloured books with photos, graphic novels and comics.

I find the Nxtpaper 11 (10.9″ 16: 10 aspect) best for notes due to being much smaller & lighter than the Nxtpaper 14 (The pro version of it is for gaming) and the Nxtpaper 14 is a much better size than the Nxtpaper 11 pro for PDFs.

Edit:
The Nxtpaper 2.0 & 3.0 LCD and OLED models look totally like a new display technology. They make the iPad look like garbage. They do not look like regular LCD or OLED models. I've not seen the recent Lenovo and Huawei models that are supposed to have matt paper-like displays. Finally Apple has non-shiny screen, it's $1000 extra!

Shiny is cheap and the reflections give headaches. One of the eink ereader features that puts up the cost is the matt surface and it's got nothing to do with eink.

[rowe]

I had a nxtpaper 3 TCL40 and it was very poor as an ereader (in general the device was disappointing so I returned it). They're backlit and refresh like regular phone/tablet screens - both of which cause more eyestrain than e-ink (bistable, not backlit). The epaper marketing for them is misleading.

[Quoth]

Originally Posted by rowe

I had a nxtpaper 3 TCL40 and it was very poor as an ereader (in general the device was disappointing so I returned it).

Perhaps you had the settings wrong. I've had many mobile phones (first was one of the first analogue Nokia phones that didn't look like a brick), inc iPhone and Sony. I've found the TCL Nxtpaper 3.0 40 4G to be the best, and while not as good as eink with front light off in decent ambient light, properly adjusted it's as good as eink with front light on.

Originally Posted by rowe

They're backlit and refresh like regular phone/tablet screens - both of which cause more eyestrain than e-ink (bistable, not backlit). The epaper marketing for them is misleading.

The eyestrain on most OLED or LED screens is nothing to do with refresh (everything not eink) vs Bistable (eink) but that most are shiny so unconsciously focusing on the reflections causes the headache. This was established with CRTs on the 1970s. Real matt screens have existed since then but are rare.

I was in a showroom of Apple products today and the screens were excessively shiny with "beautifully" sharp reflections of the bright ceiling strip-lights. That would give you a headache. Especially bad is any reflected movement.

Interlace screens on some graphics modes on CRTs or Plasma gave excessive flicker for single pixel high detail. Such as CGA on an NTSC TV or the early 1024 x 768 interlace mode for 640 x 480 progressive CRTs.

Almost all eink screens have a micro-etched surface to make them matt. Nothing to do with being bistable or eink.

The other lesser problems are the screen too bright (some do this with eink front lights), or cheap LCDs with poor viewing angle.

The Bistable eink only has a real advantage visually over LCD/OLED with decent refresh rates and a matt surface if the front light is off in adequate ambient light.

Note TCL default settings are poor, as are those on EVERY phone, tablet and Monitor I've used EVER!


Shiny is cheap. Matt surface keeping sharpness of display is very expensive.

If you can use a turned off display as a mirror it's garbage. If you can make out what is reflected it's poor. Nothing to do with eink/bistable vs any other display.

The other advantage of bistable eink is nothing whatsoever to do with eyestrain, but battery life because the CPU can sleep till you turn the page. This advantage is nearly gone on eink because:
1. Eink larger screens, front light, BT, WiFi, faster CPUs, audio, quick touch response. Flipping pages now uses far more power.

Vs

2. On LCD/OLED more efficient displays, better CPU power management and batteries of x4 to x20 capacity or more of eink models. Faster charging up to x20 of 20 years ago.

You can now get longer run time on some phones listening to an Audio book than on any eink model that can do audio books.


People mostly have screens set too bright. Compare with brightness of a paperback (or eink with front light off), but not laser/copier paper under the ambient light.

[rowe]

Sure, glare from glossy screens can contribute to eyestrain.

But reflections are far from being only issue, and a minor issue for me. The relative reading comfort of e-ink for most people comes from a number of factors.

You are staring into a light source with an LCD/OLED, versus viewing reflected light with e-ink. Studies have directly measured significantly higher rates of visual fatigue and tired eyes after prolonged reading sessions with direct light.

Yes the obvious flicker of old CRTs is gone, but PWM and Temporal Dithering (Frame Rate Control - FRC) are a real issues on most non-eink screens. This sensitivity is not just anecdotal, flicker from light sources is a known cause of headaches and eyestrain. PWM has been measured on the TCL40/TCL Nxtpaper 14 at low light, despite their 'flicker-free' claims.

These symptoms vary by individual, but each is significant for a meaningful portion of the population. I tried lots of settings on the TCL including light level, and reading comfort was very poor for me compared to any e-ink device (including those with gloss surfaces).

Perhaps they've improved with Nxtpaper 4, but I'm wary due to the misinformation and gimmicks that came with the previous generations. They're still using temporal dithering by default on Nxtpaper 4 but looks like they'd added an option to switch it off in regular mode so I might give them another try.

[Quoth]

Light source vs reflected makes no difference if they are the same. See point about people have the brightness too high. LED Frontlight vs rear light makes no difference at the same level.

Some eink frontlight LEDs are PWM.

Not all PWM gives human affecting flicker either.

Not all CRTs had flicker.

Studies have directly measured significantly higher rates of visual fatigue and tired eyes after prolonged reading sessions with direct light.

Which studies? That's a nonsense assertion for a correctly adjusted screen vs ANY reflective / shiny screen surface. Light is light. At the same brightness it doesn't matter if a backlight, frontlight or ambient.

Ambient (no frontlight) can be better, but for reasons of not having to adjust the colour temperature or brightness. If indoors with controlled ambient light and correctly adjusted matt screen, an ambient light only based bistable screen has little advantage and one needing a frontlight has none.


Yes, all the fancy "epaper" settings on TCL Nxtpaper are marketing gimmicks. Simply regular sRGB with brightness and colour temperature adjusted works best.

The issues of colour dithering are contentious and don't apply to reading monochrome text. For static colour content it's hugely better than Gallery 3 which is far too slow for an ereader. Kaleido is a joke for colour except for already dithered comic books mimicing 1930s pulp quality.

Glossy screens with sharp reflections (especially if moving) are proved 50 years ago to be the main cause of headaches. The technology to avoid that is over 30 years old for LCD but companies like Apple would rather make higher profit (Now $1000 extra for a matt surface screen).

[rowe]

For a large number of users glare from glossy screens and improperly adjusted screen brightness are significant factors contributing to eyestrain. However, they are not the only or even the primary causes for everyone.

My previous negative experience with Nxtpaper 3 wasn't due to a lack of fiddling with brightness or color settings. It stemmed from hardware-level mechanisms that cause severe discomfort for a significant portion of the population. There are factors beyond what is easily seen, like reflections.

"Light is light. At the same brightness it doesn't matter if a backlight, frontlight or ambient". The human visual system evolved over millennia to process light reflected off objects. Emissive displays, like LCD and OLED, are direct light sources that project photons straight into the retina.

In a 2023 Harvard study researchers found that direct backlit LCDs cause retinal cells to produce "reactive oxidative species" (ROS), a key factor in photo-oxidative damage. The study concluded that one could use an E-Ink display with a frontlight for three times longer before reaching the same level of cellular stress.
https://sid.onlinelibrary.wiley.com/...1002/jsid.1191

In contrast, a reflective mono eink display with its frontlight turned off is optically analogous to paper. It emits no light of its own. Even when its frontlight is on, the light is diffused across the screen's surface before reflecting to the eye - a far less direct and aggressive pathway than a backlight. The Harvard study confirms that even front-lit eink is significantly less stressful on retinal cells than a backlit LCD.

Beyond the nature of the light source, its stability is important. PWM rapidly cycles the backlight between 100% ON and 100% OFF. The ratio of on-time to off-time creates the perception of reduced brightness. While most people cannot consciously perceive flicker above around 90Hz, our neurological system can detect it at far higher frequencies, leading to headaches, migraines, and fatigue.

Even more problematic for some is Temporal Dithering (aka FRC). Using FRC panels rapidly flash adjacent pixels between shades of colours, tricking the brain into perceiving a desired colour otherwise beyond the capability of the panel. This constant, high-frequency pixel-level flashing is a known cause of severe neurological symptoms in many users.

Flicker sensitivity is an extremely common condition estimated to affect the majority of computer users. While the causes are multi-factor, sensitivity to the high-frequency flicker from PWM and FRC is a major contributor. Many who report headaches and fatigue from screens are likely reacting to this flicker without knowing its source.

Sensitivity is not a binary switch, it’s a spectrum. One person may be entirely unaffected by PWM on a device, while for another it is debilitating. Even for those who do not feel immediate symptoms, research shows that the brain subconsciously detects flicker up to 200Hz, which can still cause fatigue and reduce cognitive performance over time.

[Quoth]

Originally Posted by rowe

"Light is light. At the same brightness it doesn't matter if a backlight, frontlight or ambient". The human visual system evolved over millennia to process light reflected off objects. Emissive displays, like LCD and OLED, are direct light sources that project photons straight into the retina.

In a 2023 Harvard study researchers found that direct backlit LCDs cause retinal cells to produce "reactive oxidative species" (ROS), a key factor in photo-oxidative damage. The study concluded that one could use an E-Ink display with a frontlight for three times longer before reaching the same level of cellular stress.
https://sid.onlinelibrary.wiley.com/...1002/jsid.1191
.

Sorry but this is garbage. It is not valid science.

Multiple studies over decades show the issue is reflections because the eyes unconsciously refocus from reading distance to the reflected image distance. It's worse if the reflections move.

Even the claims of "blue light" are pretty much now rubbished. It's stimulating content, not the "blueness" of the light that keeps people awake after they turn it off.

[rowe]

You've made the extraordinary claim that reflections are the sole cause of eye strain, a claim for which you've provided no evidence, choosing instead to dismiss a peer-reviewed Harvard study as 'garbage' without any reasoned argument.

Let's be clear on the facts...

Digital Eye Strain is multifactorial: Every reputable source, from the American Optometric Association to countless ophthalmology studies, confirms that eye strain from displays has multiple causes. These include flicker (from PWM and FRC) and the fundamental difference between emissive and reflected light. Claiming that it's only due to reflections is demonstrably false.

The science is valid: The Harvard study you dismissed found that backlit LCDs cause two to three times more cellular stress than front-lit e-paper displays. That's a measurable, scientific finding. It's just one of many studies that supports these basic findings.

History is being misrepresented: Eye strain from CRTs in the 1970s was also due to multiple factors with flicker being a primary and well-documented cause, not just reflections.

Provide a credible study that proves reflections are the sole cause of digital eye strain. Without supporting evidence, it's nothing more than an unsubstantiated personal opinion.