Robust 7"-8" upgrade for PW2

[Quoth]

Originally Posted by John F

Unless/until some new tech comes out, I'm guessing I would be happy with my current eink reader (a Clara 2E).

I don't see higher DPI making a big difference, and although I appreciate improvements in contrast, I don't see a huge leap in contrast in the next 10 years.

I'm thinking something besides a newer "screen" would get me to buy a new reader, like bluetooth page turning devices. Although a foldable "screen" might get me interested.

And I'm looking forward to user replaceable batteries.

For mono you don't need more than 300 dpi because it's 14 shades with black and white. Mono laser printer is only black or white, so 600 and then 1200 dpi made a big difference. Same true originally on inkjet, but then they figured how to vary dot size.

With 1200 dpi mono eink for a Kaleido screen you'd have decent 300 dpi mono, as good as mono eink and more grey shades. You'd have 300 dpi colour too with more than 4096 colours because of dithering at 600 dpi. But with color eink, there is only decent colour range if the dots are entirely R, G & B, thus a bright front light is always needed. So Kaleido would not be much improved by 1200 dpi, except you'd have better mono.

The LiPoly cell (a battery implies more than one cell and I've never seen that except in laptops) can be replaced easily in most Kobos, some Kindles and other Kindles it's nearly impossible.


But we've had 300 dpi eink for over 10 years. Though the 10.3″ has only just caught up and 13″ etc are still less than 300 dpi.

[Renate]

Originally Posted by Quoth

For mono you don't need more than 300 dpi because it's 14 shades with black and white.

Well, until they fix that I refuse to read Fifty Shades of Grey!

* I probably will never read it anyway.

[Quoth]

Originally Posted by Renate

Well, until they fix that I refuse to read Fifty Shades of Grey!

* I probably will never read it anyway.

Here is a nice intro to dithering.
https://tannerhelland.com/2012/12/28...urce-code.html

Note that the fast Bayer method (at the end) may look nearly as good as the best (and more compute intensive) error diffusion schemes if the dpi is high enough. So a 150 dpi colour image can look very good on a 1200 dpi printer that can only add yellow, cyan, magenta and black dots. Printers use CYMK rather than R G B for two reasons: 1) decent saturated RGB dots are about 1/5th brightness of yellow on paper. 2) CYMK is additive (e.g. Cyan is overprinted with Yellow for green) so gives better resolution than RGB which needs adjacent dots.

With eink, at least there is more than just black and white dots. However at 1200 dpi the faster refresh mode that doesn't do greys could be used for text and some grey scale images with less dithering than at 150 dpi (Kindle DX) to 300 dpi (most ereaders now).

[Renate]

Educational!

Here's a dithered Mr. Dithers.

[Quoth]

Also at 150 dpi image quality, mono would need 1200 dpi for fast 8x8 Bayer style dithering. Error diffusion solutions need a lot more CPU and RAM.

You can see what 14 grey, black and white without dither at 150 dpi is like if you have a Kindle DXG (The DX is older viziplex screen type and much poorer, the DXG is Pearl without light pipe for front light or capacitive touch, so is reasonable in decent ambient light, though greyer than Carta)

https://en.wikipedia.org/wiki/Ordere...threshold_maps

Kaleido would need 2400 dpi for 8x8 Bayer matrix. A 4x4 Bayer looks rubbish compares to the 3 main Error diffusion algorithms.

A 1200 dpi mono eink would allow faster refresh as only pure black and white pixels would be needed. Grey scale is much slower.

[JSWolf]

Originally Posted by Renate

Well, until they fix that I refuse to read Fifty Shades of Grey!

* I probably will never read it anyway.

It's not broken. So it doesn't need fixing. Enjoy your pornography book when you read it.

[JSWolf]

Originally Posted by Quoth

Also at 150 dpi image quality, mono would need 1200 dpi for fast 8x8 Bayer style dithering. Error diffusion solutions need a lot more CPU and RAM.

You can see what 14 grey, black and white without dither at 150 dpi is like if you have a Kindle DXG (The DX is older viziplex screen type and much poorer, the DXG is Pearl without light pipe for front light or capacitive touch, so is reasonable in decent ambient light, though greyer than Carta)

https://en.wikipedia.org/wiki/Ordere...threshold_maps

Kaleido would need 2400 dpi for 8x8 Bayer matrix. A 4x4 Bayer looks rubbish compares to the 3 main Error diffusion algorithms.

A 1200 dpi mono eink would allow faster refresh as only pure black and white pixels would be needed. Grey scale is much slower.

Sometimes Kindles can do a terrible job of dithering.

[pypeke]

Originally Posted by John F

Unless/until some new tech comes out, I'm guessing I would be happy with my current eink reader (a Clara 2E).

And I'm looking forward to user replaceable batteries.

I know that 3 Kobos (Libra Colour, Clara Cloour, and Clara B&W) CAN be repaired with help from I-Fix-It videos and parts. If Kobo is serious about recycling plastic, then it makes sense that Kobo would start making all new ereaders repairable. Will see how these 3 models do.

DIY: battery, display, motherboard, front cover, back cover.

But, only AFTER the warranty has expired.


https://help.kobo.com/hc/en-us/artic...-eReader#Three


My next laptop will be a "Framework" laptop so that I can replace parts.

[pypeke]

Originally Posted by DanCa

I am looking for an upgrade to my rooted PW 2 ('13) , which I love dearly and use for many hours a day.

This leaves the following readers:

- Kobo Libra 2 Color
- Pocketbook Era (but this seems to be underpowered compared to the Era Color)
- Pocketbook Era Color
- Maybe an older Pocketbook Inkpad 3 with a 7.8" screen. (even more underpowered)


Which one should I get? Do I have to worry about breaking the newer readers?

Libra 2 Color? I think you mean Libra Colour. (1st edition, not to be confused with Libra 2.)


https://comparisontabl.es/e-readers/

PocketBook's InkPad Color 3 and Inkpad Color 2 are almost identical according to Guido's table (above link). I would check PB's website.

Color 3 shows NO speaker and Gold color vs. Color 2 shows a speaker and Silver color.

Color 3 has Linux 3.10.65 listed and Color 2 has Linux 4.9.56 listed.

Color 3 lists Kaleido 3 and Color 2 has Kaleido Plus.

Also, PocketBook's InkPad 4 is not color, but it so 7.8" like the Color 2 & 3.



Alas, it looks like the OP has not had time to respond since he posted.

[DanCa]

I just managed to get a slightly used display model of the Forma, they still sell on Aliexpress for $120 (8G) to $150 (32G).

Lot's of good comments on the thread, thank you all! I even understand dithering now.

Libra 2 Color? I think you mean Libra Colour. (1st edition, not to be confused with Libra 2.)

yes, Libra Color. I got that wrong.

https://comparisontabl.es/e-readers/

PocketBook's InkPad Color 3 and Inkpad Color 2 are almost identical according to Guido's table (above link). I would check PB's website.

I found some more info here: https://www.mobileread.com/forums/sh...d.php?t=356710, it seems they ran out of Kaleido+ for the InkPad Color 2 and made the Color 3 with the same specs but Kaleido 3.

Also, PocketBook's InkPad 4 is not color, but it so 7.8" like the Color 2 & 3.

Amazon had refurbished InkPad 3s for around $150.

[pypeke]

Originally Posted by DanCa

I just managed to get a slightly used display model of the Forma, they still sell on Aliexpress for $120 (8G) to $150 (32G).




Amazon had refurbished InkPad 3s for around $150.

Glad you found one. I am looking for a Libra 2 which is probably not going to be found.

[John F]

FWIW, I believe the Tolino Vision 6 is the same hardware as the Libra 2, although the software is different.

[DanCa]

Originally Posted by pypeke

Glad you found one. I am looking for a Libra 2 which is probably not going to be found.

The Formas suddenly popped up in quantity after being unavailable for weeks, might be worth keeping an eye on google shopping and aliexpress.

[pypeke]

Thanks.

[Renate]

Originally Posted by Quoth

A 4x4 Bayer looks rubbish...

I beg to differ.