OS 2.5 and contrast

tribble · 07-27-2006, 07:27 AM

Has anyone else the feeling, that the contrats got worse in OS 2.5?

I seem to have more ghosting, and especially, the black is not as dark as before.

Or am i just seeing things?

ali · 07-27-2006, 07:32 AM

I got that feeling before updating to 2.5. I had the impression that contrast was low when it was hot outside, as if the pigments won't stay in place if everything is hot.

Naturally, it could also be that the charge of the pigments wears off with time. But I surely hope not within the first two weeks...

ElaHuguet · 07-27-2006, 07:36 AM

I haven't noticed any difference. What I noticed DOES make a difference is the lighting, flourescent (or daylight) provides a much better contrast, makes the screen "whiter".

tribble · 07-27-2006, 07:36 AM

It could be a temperature thing. It was quite hot, when i noticed it. I also noticed a clouding. Like some parts have better contrast then others.

R2D2 · 07-27-2006, 08:53 AM

The contrast of electronik ink does decrease with the time. Unfortunately E-Ink does not give any half life time on their developer forum...

I also got some pretty severe ghosting (white on black)...

R2D2 · 07-27-2006, 08:56 AM

Maybe they experimented with the refresh waveform file...

tribble · 07-27-2006, 09:23 AM

Quote:

Originally Posted by R2D2

Maybe they experimented with the refresh waveform file...

Thats what i was thinking. reduce power to refresh the screen, to get longer battery life. Doesnt look so good, i think.

wiljo · 07-27-2006, 09:42 AM

I also had the feeling, that the contrast was not as good as with 2.4.
Also ghosting seemed more severe.

But since I have "ultimate ghosting" (page never gets cleared anymore) now (I got my ticket number, see here:
https://www.mobileread.com/forums/sho...?t=7068&page=2 )
I dont know, whether my display just showed "rapid ageing".

But it could be a bug introduced in 2.5, maybe my "ultimate ghosting" can also just be fixed by 2.6 . Could be that the driver is "hung in some state".

Well, well, ....

tribble · 07-29-2006, 02:30 AM

I have been reading now, for quite some time, and its not that hot anymore, and it is still that the contrats is worse than 2.4. I askes iRex about it, and i will post the answer here, if i get one.

(btw, my battery lastet a bit over 8 hours while mostly lying around and reading about 100 pages.)

tribble · 08-02-2006, 12:36 PM

Got this answer from irex:

Quote:

Originally Posted by iRex

Thanks you for your feedback, we are currently looking into this. Whenever we send a new software release it is possible that we make small alterations to our waveforms to optimize the screen quality also since release 2.5 we now use a higher DPI setting for our display. Instead of 100dpi, the software setting for the display is now 160dpi.

We continue our R&D program to improve the display and this problem will most likely be fixed with the upcoming software releases.

Kind regards,

The iRex Team

TadW · 08-02-2006, 12:43 PM

So they changed from 100dpi to 160dpi (dots per inch)? What exactly does that mean? According to the Wiki, the iLiad display has roughly 160ppi (pixels per inch). How does the math work here?

tribble · 08-02-2006, 12:56 PM

Quote:

Originally Posted by TadW

So they changed from 100dpi to 160dpi (dots per inch)? What exactly does that mean? According to the Wiki, the iLiad display has roughly 160ppi (pixels per inch). How does the math work here?

I would assume, that hat has to do with calculation base. the physical maximum is 160 dpi, but images where calculated with 100 dpi.

jamesarm97 · 08-02-2006, 10:07 PM

Quote:

Originally Posted by tribble

I would assume, that hat has to do with calculation base. the physical maximum is 160 dpi, but images where calculated with 100 dpi.

If they have been calculating at 100dpi then wouldn't that mean the page image is rendered at 480x640 then stretched to 768x1024? 4.8" (122mm wide) x 100dpi = 480 pixels. 4.8" x 160dpi = 768 pixels. Does this mean the new render dpi of 160 would make the screen images look better or is this already in v2.5 or am I completely off base with this.

- James

DrBibber · 08-03-2006, 12:14 AM

If you ask me, they are fooling us. I am in the publishing business and from my experience with image reproduction, they are saying nonsense. It has nothing to do with ppi's.

What they say, that the screen has been running at 100 dpi in a low resolution as calculated above. But if you run a screen in a lower resolution, it is getting blurred and that always causes a loss of contrast. Increasing the dpi rates keeps the image sharper and causes higher and better contrast.

Imagine a line in a low resolution. The line goes not straight from white to black, it has a shadowy region, because it is interpolatet with the region around. In higher resolution, this "shadows" get much smaller and you have a more brilliant line. The contrast is better in high resolutions.

For me it sounds that they wanted to say something very technical which we have to accept. Sometimes we do the same with our authors :-D

Playing with "waveforms" whatever that means is maybe more the case here.

R2D2 · 08-03-2006, 04:22 AM

Quote:

Originally Posted by DrBibber

Playing with "waveforms" whatever that means is maybe more the case here.

Apparently:

The cells of the display are refreshed in waves. The exact way that this is done, is defined in a waveform file, which is stored somewhere on the iLiad. By changing this file they can change the way the screen is refreshed, resulting in faster or slower screen refresh with better or worser contrast with better or worser ghosting. It seems that the "best" waveform has not been found yet...

So it does make sense what they say, although it would be interesting to have a 2.4 and a 2.5 iLiad side by side. Did anybody buy two of them? ;-)

07-27-2006, 07:27 AM	#1
tribble iLiad Maniac Posts: 1,382 Karma: 2369 Join Date: Apr 2006 Location: Germany Device: Bookeen Opus (i love that thing) and iPad (what an irony)	OS 2.5 and contrast Has anyone else the feeling, that the contrats got worse in OS 2.5? I seem to have more ghosting, and especially, the black is not as dark as before. Or am i just seeing things?

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07-27-2006, 07:32 AM	#2
ali Addict Posts: 302 Karma: 116 Join Date: May 2006 Device: Iliad, dude!	I got that feeling before updating to 2.5. I had the impression that contrast was low when it was hot outside, as if the pigments won't stay in place if everything is hot. Naturally, it could also be that the charge of the pigments wears off with time. But I surely hope not within the first two weeks...

07-27-2006, 07:36 AM	#3
ElaHuguet iLiad freak Posts: 339 Karma: 243 Join Date: Apr 2006 Location: Mallorca, Spain Device: iRex iLiad	I haven't noticed any difference. What I noticed DOES make a difference is the lighting, flourescent (or daylight) provides a much better contrast, makes the screen "whiter".

07-27-2006, 08:53 AM	#5
R2D2 Mad Scientist Posts: 294 Karma: 242 Join Date: May 2006 Location: Germany Device: Zaurus, HTCMagician, iLiad	The contrast of electronik ink does decrease with the time. Unfortunately E-Ink does not give any half life time on their developer forum... I also got some pretty severe ghosting (white on black)...

07-27-2006, 08:56 AM	#6
R2D2 Mad Scientist Posts: 294 Karma: 242 Join Date: May 2006 Location: Germany Device: Zaurus, HTCMagician, iLiad	Maybe they experimented with the refresh waveform file...

07-27-2006, 09:42 AM	#8
wiljo Member Posts: 23 Karma: 10 Join Date: Jul 2006 Device: iLiad	I also had the feeling, that the contrast was not as good as with 2.4. Also ghosting seemed more severe. But since I have "ultimate ghosting" (page never gets cleared anymore) now (I got my ticket number, see here: https://www.mobileread.com/forums/sho...?t=7068&page=2 ) I dont know, whether my display just showed "rapid ageing". But it could be a bug introduced in 2.5, maybe my "ultimate ghosting" can also just be fixed by 2.6 . Could be that the driver is "hung in some state". Well, well, ....

07-29-2006, 02:30 AM	#9
tribble iLiad Maniac Posts: 1,382 Karma: 2369 Join Date: Apr 2006 Location: Germany Device: Bookeen Opus (i love that thing) and iPad (what an irony)	I have been reading now, for quite some time, and its not that hot anymore, and it is still that the contrats is worse than 2.4. I askes iRex about it, and i will post the answer here, if i get one. (btw, my battery lastet a bit over 8 hours while mostly lying around and reading about 100 pages.)

08-02-2006, 12:43 PM	#11
TadW Uebermensch Posts: 2,583 Karma: 1094606 Join Date: Jul 2003 Location: Italy Device: Kindle	So they changed from 100dpi to 160dpi (dots per inch)? What exactly does that mean? According to the Wiki, the iLiad display has roughly 160ppi (pixels per inch). How does the math work here?

08-03-2006, 12:14 AM	#14
DrBibber Iliad geek Posts: 37 Karma: 10 Join Date: Jul 2006 Device: Iliad	If you ask me, they are fooling us. I am in the publishing business and from my experience with image reproduction, they are saying nonsense. It has nothing to do with ppi's. What they say, that the screen has been running at 100 dpi in a low resolution as calculated above. But if you run a screen in a lower resolution, it is getting blurred and that always causes a loss of contrast. Increasing the dpi rates keeps the image sharper and causes higher and better contrast. Imagine a line in a low resolution. The line goes not straight from white to black, it has a shadowy region, because it is interpolatet with the region around. In higher resolution, this "shadows" get much smaller and you have a more brilliant line. The contrast is better in high resolutions. For me it sounds that they wanted to say something very technical which we have to accept. Sometimes we do the same with our authors :-D Playing with "waveforms" whatever that means is maybe more the case here.

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