Screens very different K4/KT

JSWolf · 01-14-2012, 09:17 PM

Today I was at Walmart and saw two demo Kindles. I saw the K4 and the KT. The screen were very different. The KT's screen had a darker background and the text was not as black. The K4 had a lighter background and blacker text. This is with the same book, the same font settings. Is the KT that bad overall?

tovare · 01-14-2012, 10:14 PM

Potential manufacturing differences is an interesting topic, and some reports in this forum noted the oposite of your finding (suggesting that K4 simply had a lower grade screen due to the lower price). Now it seems just random

I have the K4 and K3 and I have a hard time deciding if there is a quality difference.

- I think I see greyer letters on the K4 when viewing the screen at a 90 degree angle, but light seems to be better dispersed at an angle. (I might be wrong because the effect isn't that huge). Did you view them at the same angle?

- There's seems to be a slight difference in the shades of grey when rendering images (I assume it's firmware related and might give a difference to KT vs K4).

- The bezel color has an effect on appearence (Which is immediately apparent when comparing the K3 and K4, but the bezel on the KT and K4 is almost the same)

Haesslich · 01-14-2012, 10:16 PM

I thought that was just the height of the bezel to include the infrared sensor grid that made the screen not look as good.

Ironically, Tom's Hardware said the K4 used a lower grade of screen than the Kindle Touch. It sure doesn't look that way - I'd pit it against the K3 anytime. I do like the smaller size.

JSWolf · 01-14-2012, 10:42 PM

The K4 & KT were not damaged. They were in the same lighting and in the stands at the same angle. So those variables are not part of the mix. But I definitely saw the screen on the KT to be darker and of less contrast then the K4. I would have pit the Vizplex screen on my old 505 against it.

I do think that Amazon should be turning these things on before shipping to make sure the screen is of a certain standard. A demo unit that looks that bad is going to turn potential customers away.

HarryT · 01-15-2012, 03:51 AM

The screens are the same - there is only one source of eInk screens. There can be variation between individual eInk panels, but it's not tied to the model of reader they're installed in.

Haesslich · 01-15-2012, 04:11 AM

http://www.tomshardware.com/reviews/...er,3040-3.html

This came from the Tom's Hardware review of the K4 non-Touch. They seem to believe the K4 uses a cheaper batch... but, as far as I can tell, there's no real difference in grade, so much as individual QC on each screen. In the case of the Kindle Touch, either it was a bad screen n the demo, or else the lower height of the non-Touch bezel that let the light reflect better.

HarryT · 01-15-2012, 04:18 AM

And many other people have said that they're talking nonsense - there are no different "grades" of eInk screen, as that review claims there are.

This was all thrashed out months ago; you may wish to go back and review the old threads on the subject.

Serpentine · 01-15-2012, 07:35 AM

Quote:

Originally Posted by Haesslich

This came from the Tom's Hardware review of the K4 non-Touch.

Tom's Hardware isn't exactly a good source of information.

JoHunt · 01-15-2012, 09:33 AM

Quote:

Originally Posted by JSWolf

I do think that Amazon should be turning these things on before shipping to make sure the screen is of a certain standard. A demo unit that looks that bad is going to turn potential customers away.

I presume you are mentioning this because you are a potential customer

My KT has the exact same screen/text color as a friend's K4 (it also has the same screen as my K3).

Haesslich · 01-15-2012, 12:37 PM

Quote:

Originally Posted by HarryT

And many other people have said that they're talking nonsense - there are no different "grades" of eInk screen, as that review claims there are.

This was all thrashed out months ago; you may wish to go back and review the old threads on the subject.

As I said, there appears to be no difference, but I've seen that review referenced elsewhere as a reason not to get the K4 non-Touch, like at The Gadgeteer. The reviewer ultimately got a K4 NT and saw no difference either. Any variances seem to be more QC related - I've had two K3's (one of which broke and had to be RMA's for the second) any my newer one has a lighter screen than my first did.

Skydog · 01-15-2012, 03:59 PM

I've compared a KT, K4 and K3 (keyboard) side by side indoors and outdoors in direct sunlight. All three displays were identical - excellent.

JSWolf · 01-15-2012, 04:37 PM

Since this difference does exist, I would think it would be in Amazon's best interest to check each Kindle before it gets sent out.

Rizla · 01-15-2012, 05:25 PM

Quote:

Originally Posted by HarryT

And many other people have said that they're talking nonsense - there are no different "grades" of eInk screen, as that review claims there are.

Care to back that up with proof?

AnemicOak · 01-15-2012, 05:36 PM

Quote:

Originally Posted by JSWolf

Since this difference does exist, I would think it would be in Amazon's best interest to check each Kindle before it gets sent out.

eInk devices from all manufacturers can have differences in screen appearance based on the individual panels.

geekmaster · 01-15-2012, 08:00 PM

The Kindle pearl eInk screen contrast depends greatly on temperature, how long it has sat idle since the last screen refresh, and how many pages since a full flash update.

Because the new kindles do not do a full flash update on every page, comparing two identical kindles side-by-side will yield different results at different times.

The screen contrast is much better when the displays are warm, because they contain dark oil-filled beads. The oil viscosity changes with temperature. The screens contain a temperature sensor, which is used by the display driver software to tune the screen refresh algorithm to compensate for temperature differences. The beads also contain zinc oxide powder, which is attracted to the top or bottom surface of the screen with an electrical charge, with controlling waveforms that must be adjusted in both period and magnitude to maximize contrast.

The only realistic method to compare two units is to let them sit together awhile to equalize temperatures, then to exercise the screens by viewing multiple pages, then go to the page to compare and force multiple screen full flash updates. This can be done in a number of ways, such as taking a screen snapshot, or selecting and deselecting the menu.

Any other conclusion from comparing two units is a silly waste of nonsense.

01-14-2012, 09:17 PM	#1
JSWolf Resident Curmudgeon Posts: 73,883 Karma: 128597114 Join Date: Nov 2006 Location: Roslindale, Massachusetts Device: Kobo Libra 2, Kobo Aura H2O, PRS-650, PRS-T1, nook STR, PW3	Screens very different K4/KT Today I was at Walmart and saw two demo Kindles. I saw the K4 and the KT. The screen were very different. The KT's screen had a darker background and the text was not as black. The K4 had a lighter background and blacker text. This is with the same book, the same font settings. Is the KT that bad overall?

01-15-2012, 08:00 PM	#15
geekmaster Carpe diem, c'est la vie. Posts: 6,433 Karma: 10773668 Join Date: Nov 2011 Location: Multiverse 6627A Device: K1 to PW3	The Kindle pearl eInk screen contrast depends greatly on temperature, how long it has sat idle since the last screen refresh, and how many pages since a full flash update. Because the new kindles do not do a full flash update on every page, comparing two identical kindles side-by-side will yield different results at different times. The screen contrast is much better when the displays are warm, because they contain dark oil-filled beads. The oil viscosity changes with temperature. The screens contain a temperature sensor, which is used by the display driver software to tune the screen refresh algorithm to compensate for temperature differences. The beads also contain zinc oxide powder, which is attracted to the top or bottom surface of the screen with an electrical charge, with controlling waveforms that must be adjusted in both period and magnitude to maximize contrast. The only realistic method to compare two units is to let them sit together awhile to equalize temperatures, then to exercise the screens by viewing multiple pages, then go to the page to compare and force multiple screen full flash updates. This can be done in a number of ways, such as taking a screen snapshot, or selecting and deselecting the menu. Any other conclusion from comparing two units is a silly waste of nonsense. Last edited by geekmaster; 01-16-2012 at 09:33 AM.

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01-14-2012, 10:14 PM	#2
tovare Addict Posts: 221 Karma: 1133312 Join Date: Sep 2009 Location: Oslo/Norway Device: PRS-600, Kindle kb Wifi, new Kindle NT, PW2, Kindle Oasis	Potential manufacturing differences is an interesting topic, and some reports in this forum noted the oposite of your finding (suggesting that K4 simply had a lower grade screen due to the lower price). Now it seems just random I have the K4 and K3 and I have a hard time deciding if there is a quality difference. - I think I see greyer letters on the K4 when viewing the screen at a 90 degree angle, but light seems to be better dispersed at an angle. (I might be wrong because the effect isn't that huge). Did you view them at the same angle? - There's seems to be a slight difference in the shades of grey when rendering images (I assume it's firmware related and might give a difference to KT vs K4). - The bezel color has an effect on appearence (Which is immediately apparent when comparing the K3 and K4, but the bezel on the KT and K4 is almost the same)

01-14-2012, 10:16 PM	#3
Haesslich Fanatic Posts: 542 Karma: 1138182 Join Date: Sep 2009 Device: Kobo Touch,Glo,Mini,Aura/HD/One,H20, Sony PRS-300/600, Kindle 3-PW	I thought that was just the height of the bezel to include the infrared sensor grid that made the screen not look as good. Ironically, Tom's Hardware said the K4 used a lower grade of screen than the Kindle Touch. It sure doesn't look that way - I'd pit it against the K3 anytime. I do like the smaller size.

01-14-2012, 10:42 PM	#4
JSWolf Resident Curmudgeon Posts: 73,883 Karma: 128597114 Join Date: Nov 2006 Location: Roslindale, Massachusetts Device: Kobo Libra 2, Kobo Aura H2O, PRS-650, PRS-T1, nook STR, PW3	The K4 & KT were not damaged. They were in the same lighting and in the stands at the same angle. So those variables are not part of the mix. But I definitely saw the screen on the KT to be darker and of less contrast then the K4. I would have pit the Vizplex screen on my old 505 against it. I do think that Amazon should be turning these things on before shipping to make sure the screen is of a certain standard. A demo unit that looks that bad is going to turn potential customers away.

01-15-2012, 03:51 AM	#5
HarryT eBook Enthusiast Posts: 85,544 Karma: 93383043 Join Date: Nov 2006 Location: UK Device: Kindle Oasis 2, iPad Pro 10.5", iPhone 6	The screens are the same - there is only one source of eInk screens. There can be variation between individual eInk panels, but it's not tied to the model of reader they're installed in.

01-15-2012, 04:11 AM	#6
Haesslich Fanatic Posts: 542 Karma: 1138182 Join Date: Sep 2009 Device: Kobo Touch,Glo,Mini,Aura/HD/One,H20, Sony PRS-300/600, Kindle 3-PW	http://www.tomshardware.com/reviews/...er,3040-3.html This came from the Tom's Hardware review of the K4 non-Touch. They seem to believe the K4 uses a cheaper batch... but, as far as I can tell, there's no real difference in grade, so much as individual QC on each screen. In the case of the Kindle Touch, either it was a bad screen n the demo, or else the lower height of the non-Touch bezel that let the light reflect better.

01-15-2012, 04:18 AM	#7
HarryT eBook Enthusiast Posts: 85,544 Karma: 93383043 Join Date: Nov 2006 Location: UK Device: Kindle Oasis 2, iPad Pro 10.5", iPhone 6	And many other people have said that they're talking nonsense - there are no different "grades" of eInk screen, as that review claims there are. This was all thrashed out months ago; you may wish to go back and review the old threads on the subject.

01-15-2012, 03:59 PM	#11
Skydog Wizard Posts: 2,243 Karma: 7400001 Join Date: Mar 2009 Location: Circling Earth @ Mach .83 Device: Elipsa 2E, Sage, Forma, Libra 2, Clara 2E, Kindle Oasis3, Voyage	I've compared a KT, K4 and K3 (keyboard) side by side indoors and outdoors in direct sunlight. All three displays were identical - excellent.

01-15-2012, 04:37 PM	#12
JSWolf Resident Curmudgeon Posts: 73,883 Karma: 128597114 Join Date: Nov 2006 Location: Roslindale, Massachusetts Device: Kobo Libra 2, Kobo Aura H2O, PRS-650, PRS-T1, nook STR, PW3	Since this difference does exist, I would think it would be in Amazon's best interest to check each Kindle before it gets sent out.

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