Aura H2O Uneven e-ink rendering

[tayseidel]

Having had the chance to read on both the Glo HD and the Aura H20. I have noticed that the H20 is somewhat more prone to uneven blackness in the text after multiple page turns. As a result, I've shortened the refresh rate from 12 pages to 6 pages.

The Glo HD on the other hand, seems less prone to uneven rendering of the e-ink text. On the Glo HD, I have the refresh set to refresh every 12 pages.

Just wondering if anyone has noticed uneven blackness in the e-ink on the H20? I'm wondering if this is the norm. My Glo HD does show some unevenness in the e-ink after multiple page turns, but it isn't as pronounced as the H20's unevenness. Increasing the line spacing on the H20 mitigated the effects of the e-ink unevenness somewhat.

Edit: this is using sideloaded epubs BTW.

[Alan_S]

Yes, this is normal.

Try to find books with images, large black portions make next page more pale where black portions were. If you force refresh, everything is fine.

[Erich Zann]

It's normal. Page turns on eInk device produce ghosting: black dots on a white background which are easily perceived, and also the opposite (white dots on black parts, e.g. text).

I also have a Kobo H20, and I'm very impressed (and pleased) by the few amount of ghosting of this new generation of screen. I have no problem with refreshing each 64 pages, but I must say that I can also see some irregularities on text. But they are minor to my eyes

I made some macro pictures to illustrate this.

I took one photo just after a refresh (click to enlarge):


I turned 30 pages forth and 30 pages back to get the same picture after 60 changes without any refresh:


And there is smaller part of each picture (click to enlarge):




You can see some ghost letters on the white background but to my eyes this effect is not very strong (at least compared to the previous generation of eInk, aka Pearl). It's easier on this picture to spot the uneven rendering of black text. I guess it's what you're complaining about, right?

[dordale]

I have the Aura HD which is the previous generation and I do notice some ghosting on it if I have the full page refresh rate set fairly high. It seems to vary--sometimes I have it set to 15 pages and sometimes I have to turn it back to 5 or 6 pages. I know that some of this can be related to weather conditions. When I'm reading outdoors in direct sunlight, I often have to set the refresh rate to every page. But, sometimes it's not that at all. It might be me and my eyes just being more sensitive at times, but I do find myself adjusting the full page refresh rate every so often.

[GeoffR]

Originally Posted by tayseidel

Having had the chance to read on both the Glo HD and the Aura H20. I have noticed that the H20 is somewhat more prone to uneven blackness in the text after multiple page turns. As a result, I've shortened the refresh rate from 12 pages to 6 pages.

The Glo HD on the other hand, seems less prone to uneven rendering of the e-ink text. On the Glo HD, I have the refresh set to refresh every 12 pages.

Just wondering if anyone has noticed uneven blackness in the e-ink on the H20? I'm wondering if this is the norm. My Glo HD does show some unevenness in the e-ink after multiple page turns, but it isn't as pronounced as the H20's unevenness. Increasing the line spacing on the H20 mitigated the effects of the e-ink unevenness somewhat.

Edit: this is using sideloaded epubs BTW.

Is the unevenness: 1) some parts of individual letters appearing lighter than others; or 2) some whole words or areas of the screen appearing lighter than other areas?

Although ghosting causes both types of unevenness, I think it is the choice of font that mainly the affects the first type (or at least affects how noticable it is), while it is the layout of the book that affects the second type

If you go for a number of page turns without a certain part of the screen being used, but without a refresh, then when the next page makes use of that part of the screen it will look darker than the rest of the screen.

For example, if you read with a ragged-right margin then the extreme right of the screen gets less use than the rest of it, and so when you do get a word that appears at the extreme right after a number of pages without refresh, it will look darker.

If you read with the text fully justified, and with lots of hyphenation, the words will be more evenly spread on the page and it is less likely that are patch of the screen will go unused for too many pages.

There are other things that can cause similar effects, such as paragraph spacing in some books that causes lines of text to fall in the less-used area between the lines of previous pages.

[tayseidel]

Erich Zann, I would love to have ghosting similar to what you are showing in your pics. What I am seeing is white dots on black, and it is quite extensive. Now, if this ghosting was similar to what I see on the Glo HD, then I have no problem. On the Glo HD, it’s really quite minor and not an annoyance to the eyes, like it is on the H20.

Geoff, the unevenness can be described as 2) some whole words or areas of the screen appearing lighter than other areas. That’s a perfect description of what I am seeing and I think some of it can be attributed to how the book is formatted. Some of it I think, could be a bad screen. I'm just not sure at this juncture.

I will attach a picture that shows the problem quite clearly. Justification does not work on this particular book as there is no change when I use it. The font used is Bookerly with the weight turned up a little.

The weird thing is that it is inconsistent. At times, the screen looks fine. Others, it’s horribly uneven. The pic shows what I am seeing, but there are times when the problem is more evident than shown in the picture. I took the picture just one page turn after a refresh.

I did a factory reset and the problem was still evident. So I updated to firmware 3.19.5613 again and patched it again. No difference between patched and unpatched.

Pic attached.

[PeterT]

For anyone who wants to see the image, try https://www.dropbox.com/s/aa9f9qr3spfc16b/eink.jpg

Oh well... no need for this; the o/p fixed his post

[scoky]

KOBO doesn't use eink REGAL wave form technique in its e-reader and regal wave form can reduce the uneven rendering. You can compare kindle voyage or paperwhite3, after 20 or 30 pages, the rendering is still very good.

[JSWolf]

I used to see something like the OP's picture when waking the H2O from sleep using the sleep cover in some earlier firmware versions. A double tap fixed it and so did a page turn.

[jiminrussell]

Originally Posted by scoky

KOBO doesn't use eink REGAL wave form technique in its e-reader and regal wave form can reduce the uneven rendering. You can compare kindle voyage or paperwhite3, after 20 or 30 pages, the rendering is still very good.

Doesn't the kobo aura use regal wave form? It can be set to refresh only at the start of a new chapter rather than every 1-6 pages on the other kobo readers.

[JSWolf]

Originally Posted by jiminrussell

Doesn't the kobo aura use regal wave form? It can be set to refresh only at the start of a new chapter rather than every 1-6 pages on the other kobo readers.

Yes it does.

[susmoka]

Anyone else with a Glo HD and having this issue?

The OP described as the Glo HD is good for him, but I just bought one and after the second page turn I get the same issues as shown on the pictures...
the font rendering gets uneven / it will be less sharp and sometimes less black.

[jackie_w]

Originally Posted by susmoka

Anyone else with a Glo HD and having this issue?

The OP described as the Glo HD is good for him, but I just bought one and after the second page turn I get the same issues as shown on the pictures...
the font rendering gets uneven / it will be less sharp and sometimes less black.

What value do you have in your Settings - Reading settings - Refresh the screen every x pages?

If it's currently set higher than '1 page' (I think default is 6 pages) try the 1-page setting and see if it improves things for you. If it does solve the problem you'll need to decide which is more important to you - more-even-text or faster-page-turns-plus-less-battery-use.

[JSWolf]

The topic is about the H2O. If you have an issue with a Glo HD, please start a new thread.

[MGlitch]

Originally Posted by JSWolf

The topic is about the H2O. If you have an issue with a Glo HD, please start a new thread.

Reading the OP both the H2O and Glo HD are talked about though the user states their Glo HD performs better than their H2O it hardly seems to preclude either device.