Kindle 4 screen is THE SAME as K3.

[Katsunami]

Originally Posted by Blossom

You should be fine specially if you never had a pearl screen. It's only when you had a pearl screen of amazing contrast then go back to something between vizplex and pearl that you really notice a difference. I was spoiled with my K3 but I've learn to deal with the difference my K4 has. My first K4 looked like vizplex text with dark grey background. I had it replaced to the one I use now which is light grey and almost black text. It looks like a newspaper to give a better description.

Heh :P My Cybook had a Vizplex screen, considered to be the best e-ink screen in 2007-2008. The thing even cost 400 euro's back then. When comparing it to the paperbacks printed on recycled paper (the mass market $5 ones) that I normally read, it looked very good. Vizplex was good enough for me when comparing it to those pockets; only high quality hardbacks were better.

One reason to try the ereader thing again is because the print of some pockets its getting really really small and very bad quality. So bad that with my visual handicap it is becoming very difficult to read them. Many paperbacks even can't be opened fully anymore because the spine will break and the pages start falling out. Reading a half closed book causes heavy shadows on the pages. Also, the reader will be much lighter and smaller than some of my books.

Btw... An ereader that relies on reflected light, such as the Kindle, will never be add bright add the lcd in your Fire. That is actually an advantage.... My Galaxy Tab 10.1 is way too bright, even at the lowest settings, and way to big and heavy.

[Blossom]

Originally Posted by Katsunami

Heh :P My Cybook had a Vizplex screen, considered to be the best e-ink screen in 2007-2008. The thing even cost 400 euro's back then. When comparing it to the paperbacks printed on recycled paper (the mass market $5 ones) that I normally read, it looked very good. Vizplex was good enough for me when comparing it to those pockets; only high quality hardbacks were better.

One reason to try the ereader thing again is because the print of some pockets its getting really really small and very bad quality. So bad that with my visual handicap it is becoming very difficult to read them. Many paperbacks even can't be opened fully anymore because the spine will break and the pages start falling out. Also, the reader will be much lighter and smaller than some of my books.

Because of this I think that this time, I'll keep the ereader.

Btw... An ereader that relies on reflected light, such as the Kindle, will never be add bright add the lcd in your Fire. That is actually an advantage.... My Galaxy Tab 10.1 is way to bright, even at the lowest settings, and way to big and heavy.

Get the Screen Dimm app. It what we Kindle Fire's users use because the Fire is way too bright for night reading. The Market has it for 99 cents. The developer is a member here too.

As for Vizplex, once you go Pearl you can't go back to the washout looking screen. Pearl is amazing! You're gonna love your Kindle Touch! My first reader was vizplex I don't miss it at all.

[Katsunami]

Nah. I'm not going to use the Tab to read. Too wide in landscape, too long in portrait, and weighing in at 570 grams, it's way too heavy. I actually only own 4 books that are this big. The Kindle with it's lower weight and smaller screen will be better.

Because of this, and the pockets getting worse, I think that this time, I'll keep the ereader. Changing font sizes, which the Cybook also could, is a big plus. The chance of it being a worse experience than some of my latest pockets is quite slim.... And with all the free books on Amazon that I now don't need to buy anymore (many I wanted, but never got around to yet) the reader has already paid for itself before I opened the first book on it :P

Only a few hours to wait, assuming the postman is on time. Took a day off for this to be able to tinker with it :P

[geekmaster]

Originally Posted by Blossom

Nice explanation. You wouldn't know what would make one display more susceptible to lighting condition then the other would you? My K4 is very susceptible to lighting conditions and my K3 isn't.

I've done comparisons just like you suggested to make sure I wasn't seeing things. I've compare my two units every which way till I was like what's the point. My K3 now sits on it's shelf lonely and I use my K4 for reading. I forgot how good my K3 screens Looks till I was using it the other day. So if it bothers you, only use one and you'll forget how the other one looks eventually.

Each kindle screen has custom tuning parameters stored in a ROM chip on the flex cable attached to the screen. It is possible that a screen may have been miscalibrated, or was not at the "standard" 25C temperature when it was originally calibrated, or perhaps the viscosity of the oil changed over time.

I noticed with my kindles that they improve with "exercise". There is less contrast and more ghosting for awhile when they have been unused for some time. Forcing the white zinc oxide particles to move through the oil warms it from friction. Cycling the pixels like this may also help separate white particles that may be stuck to the beads or stuck to each other.

I have 7 kindles (for software testing), and some of them get neglected for awhile. Also when they are cold (below body temperature), it makes a HUGE difference. When cold they can do different shades of "medium gray".

Store your "not so good" kindle in a warm place for a bit to "soften" the oil in the display, then test it again.

To some people the K4 and Touch may APPEAR to be lower contrast than the K3 and DXG, because of reflected light off the silver bezel affecting visual perception. Putting a "graphite" skin on the K4NT and Touch may make them appear to be higher contrast.

[Martyd]

I have read all of the possible reasons why the K4, K3 screens may be different and didn't know what to expect. My K4 arrived yesterday and I do see a difference. It's enough for me to try one exchange. My replacement is on the way. I'll only try one time and then decide if I live with it or not. I think somewhere here Blossom said she put her K3 away and moved on, which I may do, but the idea was to use the K4 for travel and the K3 at home, so I'll always be comparing. I'm not alone with this opinion, other eyes here agree with me. Oh well we'll see.

[geekmaster]

Originally Posted by Snorkledorf

I just had my Kindle 3 replaced so I took the opportunity to take some pictures.

Photography info: These were taken under artificial lighting, with the camera on a tripod. I took one photo, then carefully swapped out the Kindle and took the next photo, matching the viewfinder as best I could, to theoretically minimize differences in lighting. I then imported and aligned the photos in Pixelmator and cut bits out if needed to best show off what differences there were.

It seems the new unit's black is noticeably darker, really visibly in the "Slide..." photo. But the "Kindle" photo also seems to show that the white is darker too. Sure doesn't look that way when placed side by side though -- it looks much lighter. A contrast effect of the sharper black? Either way, it looks much clearer.

Did you disable the automatic iris or other settings that could affect the differences? Some digital cameras also auto white balance, which could affect the differences.

The biggest difference is that the kindles need to be "exercised" to warm up the dark oil in the beads, and to detach any white zinc oxide particles from the bead surfaces and break up any white clumps. Also, the default eInk display driver waveforms are tuned for 25 degrees C, so the kindles should be warmed to that temperature before any accurate comparisons can be made.

You need to do multiple full flash updates after the displays have warmed up, and THEN do you comparison photos.

[geekmaster]

Originally Posted by Martyd

I have read all of the possible reasons why the K4, K3 screens may be different and didn't know what to expect. My K4 arrived yesterday and I do see a difference. It's enough for me to try one exchange. My replacement is on the way. I'll only try one time and then decide if I live with it or not. I think somewhere here Blossom said she put her K3 away and moved on, which I may do, but the idea was to use the K4 for travel and the K3 at home, so I'll always be comparing. I'm not alone with this opinion, other eyes here agree with me. Oh well we'll see.

Fresh out of the box this time of year the kindle eInk displays WILL have low contrast and significant shadows and ghosting artifacts. You need to store it is a warm place (nearly body temperature) overnight. The lithium batteries are shipped at only 40% charge (correct long-term storage voltage). It needs a full charge (which can take up to 14 hours), then the display needs proper "exercise", before you determine its quality (or lack thereof).

If people keep sending back their new kindles just because they were delivered during a cold season in an unheated delivery vehicle, this will just raise the price on new kindles. Please test it properly before returning it.

Even my old DX (non-Pearl) display improved dramatically after it warmed up and was used for awhile.

[geekmaster]

A lot of the published "possible reasons why the K4, K3 screens may be different" are not based on proper scientific testing methodology, and do not take physical properties of the basic technology into account.

You need to do a little REAL research, instead of taking perceptual differences (graphite bezel vs. silver bezel), flawed testing (kindles not compared at proper temperature, voltage, and display "exercise" to reduce oil viscosity), potentially incorrect camera settings (failure to disable auto iris, auto white balance, auto exposure time, etc.), and biased personal opinion as "evidence" in your decision making process. There is plenty of documentation "out there" about which type of eInk technology is used in kindle displays, and how that technology works. More details (such as eInk calibration) may be found by reading the GPL source code for the eInk drivers, and by looking up part numbers of the chips used to control the eInk displays in the kindles. I have done all of these things.

Be very careful what "evidence" you use to form your opinions and make your decisions about kindle eInk display quality. We do not need more "junk science".

[Blossom]

Originally Posted by Martyd

I have read all of the possible reasons why the K4, K3 screens may be different and didn't know what to expect. My K4 arrived yesterday and I do see a difference. It's enough for me to try one exchange. My replacement is on the way. I'll only try one time and then decide if I live with it or not. I think somewhere here Blossom said she put her K3 away and moved on, which I may do, but the idea was to use the K4 for travel and the K3 at home, so I'll always be comparing. I'm not alone with this opinion, other eyes here agree with me. Oh well we'll see.

Good luck! I'll keep my fingers cross you get a good one! Yes I was the one who moved on. It doesn't matter what temp my Kindle is I use it 5 to 8 hours a day. The contrast never changes. I recommend changing the font to a bolder one. It made a world of difference to me. The default font is just very hard to read on mine unlike it is on my K3.

[geekmaster]

Originally Posted by Blossom

It doesn't matter what temp my Kindle is I use it 5 to 8 hours a day. The contrast never changes.

Thin fonts are a known problem, because of the way that kindles use gray pixels for antialiasing the fonts. The antialiasing algorithm was designed for light-emitting displays, and does not work well for passive displays like eInk. Additionally, changing an isolated pixel using an electric field slightly affects neighboring pixels (which is what causes ghosting on gray pixels). The problem is that eInk displays work best with pure black and white pixels forming the core lines and curves of font characters, which is WHY you need a bold font, to ensure that no part of the character is "gray-only". As you can see here, thin fonts have some portions that do not contain black pixels:

The top font in the image is a "standard" kindle antialiased font. The bottom one has enhanced contrast that works better on an eInk display. This is especially noticable in poorly lighted conditions, or when the eInk is operating outside its optimal environmental conditions.

The problem as shown is not with the hardware, but is instead a software problem (incorrect font rendering algorithm). This software problem is especially noticable with thin fonts that were antialiased for light-emitting displays used on eInk, when the correct thing to do would have been to use pure black and white antialiasing with pixel dispersion as is used on older laser printers.

Because this is a SOFTWARE problem, the comparison results also depend on which software versions are installed in the two kindles. A software upgrade may install a font with higher contrast.

Of course, every individual display unit is slightly different (even from the same batch), which is why they contain calibration data in a ROM on the flex cable. It is possible that your unit was not tuned correctly, or was not at the correct temperature when it was tuned. Perhaps a batch of units is statistically sampled and the whole batch uses the same tuning parameters.

Not knowing what procedure is used when calibrating these displays at the factory, it is possible that some kindles either were not tuned correctly, or deviate too far from others in the batch to look good with a "typical" set of tuning parameters (IF that is how they are done).

Perhaps somebody at amazon or lab126 can enlighten us on why *some* kindles may have inferior quality compared to others (if they have been tested properly).

[Blossom]

Originally Posted by geekmaster

Every display unit is different, which is why they contain calibration data in a ROM on the flex cable. It is possible that your unit was not tuned correctly, or was not at the correct temperature when it was tuned. Perhaps a batch of units is statistically sampled and the whole batch uses the same tuning parameters.

Not knowing what procedure is used when calibrating these displays at the factory, it is possible that some kindles either were not tuned correctly, or deviate too far from others in the batch to look good with a "typical" set of tuning parameters (IF that is how they are done).

Perhaps somebody at amazon or lab126 can enlighten us on why *some* kindles may have inferior quality compared to others (if they have been tested properly).

That would make sense about a batch using the same parameters instead of individually. I call it a bad batch. I've had mine since it was released. I got it from Amazon. The first one was much much worse. It looked Vizplex. So I kept this one in fear of getting a worse one than my first one. Maybe I shouldn't have settled.

[Martyd]

I will add that my final tests were done today and my two Kindles were stored together overnight. K4 was fully charge. I have read the previous posts about temperature and waited until today to make a decision.

[geekmaster]

Originally Posted by ApK

Interesting post of yours here:
https://www.mobileread.com/forums/sho...&postcount=265

I'm curious if you hacked a Kindle to use the better font or if that was a a different device.
If the former, what font did you change to and is it a significant difference in the reading experience?

You can actually change the contrast settings used to render fonts. There was a lot of discussion of this awhile ago in the mobileread kindle developers corner. Here is a thread with details:
https://www.mobileread.com/forums/sho...d.php?t=142848

There are a lot of bold fonts you can install too. There are some in this thread:
https://www.mobileread.com/forums/showthread.php?t=88004

[Blossom]

Originally Posted by geekmaster

Thin fonts are a known problem, because of the way that kindles use gray pixels for antialiasing the fonts. The antialiasing algorithm was designed for light-emitting displays, and does not work well for passive displays like eInk. Additionally, changing an isolated pixel using an electric field slightly affects neighboring pixels (which is what causes ghosting on gray pixels). The problem is that eInk displays work best with pure black and white pixels forming the core lines and curves of font characters, which is WHY you need a bold font, to ensure that no part of the character is "gray-only". As you can see here, thin fonts have some portions that do not contain black pixels:


The top font in the image is a "standard" kindle antialiased font. The bottom one has enhanced contrast that works better on an eInk display. This is especially noticable in poorly lighted conditions, or when the eInk is operating outside its optimal environmental conditions.

On my K4 Caecilia is dark grey. On my K3 it's black. I had to change the font on my K4. I am using Amasis that has been made heavier for the Kindle screen. Some one here modified it and did a wonderful job. It saved me from eye strain. I couldn't use my Kindle without it. It's not black but it's close enough. If there is such a color as off black. lol That would be it.

[shinew]

Originally Posted by geekmaster

Each kindle screen has custom tuning parameters stored in a ROM chip on the flex cable attached to the screen. It is possible that a screen may have been miscalibrated, or was not at the "standard" 25C temperature when it was originally calibrated, or perhaps the viscosity of the oil changed over time.

I noticed with my kindles that they improve with "exercise". There is less contrast and more ghosting for awhile when they have been unused for some time. Forcing the white zinc oxide particles to move through the oil warms it from friction. Cycling the pixels like this may also help separate white particles that may be stuck to the beads or stuck to each other.

I have 7 kindles (for software testing), and some of them get neglected for awhile. Also when they are cold (below body temperature), it makes a HUGE difference. When cold they can do different shades of "medium gray".

Store your "not so good" kindle in a warm place for a bit to "soften" the oil in the display, then test it again.

To some people the K4 and Touch may APPEAR to be lower contrast than the K3 and DXG, because of reflected light off the silver bezel affecting visual perception. Putting a "graphite" skin on the K4NT and Touch may make them appear to be higher contrast.

My understanding for most of people's complained in this thread is that some claim to notice literally "whiter" background on K3 than the K4 under any circumstances(although from my testing of 4x KT, 1x K4 & 2x K3, they're identical), including having done a full refresh, not just the texts rendering or contrast difference. Since the background is the off state for the eInk display, it should have nothing to do with the software settings or temperature when compared side by side.