MobileRead Forums - View Single Post - Kindle Paper White review : Mobileread users

Psykhe · 10-11-2012, 02:05 PM

I got my PW today and seem to have been in luck. At least I am happy with it.

I thought I might go a a bit more "scientific" with my review of its screen and its comparison to my 2 year old Kindle Keyboard. Photoshop can do more things than doing Kindle preview images for Amazon...

I.e. measuring the black level of an area.
Method used: have both Kindles next to each other equally far away from light source, take picture of both, load image in PS, convert to gray scale, use pipette tool with a decent area so you have a good average to take black level.

Minimum/Maximum:
Kindle Keyboard: 30 / 84
Kindle Paperweight: 28 / 84

So..pretty much the same without the light.

The light is, however, always on. Even when it is off (aka setting 0). It is actually bright enough to read the Kindle in total darkness, although it wouldn't really be enjoyable reading.

I do not usually read in the dark, though. This is my typical reading area and Kindle placement. With the light at minimum the difference is there still really small. But this changes considerably with a higher light level, though (12/24 in this case).

Both Kindles are equally far away from the light, the PW has a minimum grayscale of 30 in the "white" areas while the KK has one of 50! The light of the PW also looks very even with some ambient light.
Maximum grayscale is a bit trickier to measure due to the small letters, I should have used the maximum font size there, but, well, :effort: Anyway, on the PW maximum grayscale 75 is while on the KK it was 80. So there is some loss of black due to the light, but it is compensated by the increased white and then some.

Here the PW in total darkness at the same light level (12/24). The light shadows at the bottom are visible and there seems to be a green? discoloration in the upper center. But is it really there or is it just some visual illusion? I think everyone of us has seen pictures where you see shadows where there are none.

So lets do some Photoshop magic. Yes, there is definitely a light green discoloration without ambient light.
It's not because the green light is faulty, btw (that one is pretty uniform), but because red and blue light have an "hole" there.

But, honestly, I do not really care. I would have liked a perfect bleached white in darkness just as much as the next guy, but I would call it hardly a huge annoyance. And I mostly (as in 95% of the time) won't use it like this but with some ambient light. Which makes discolorations essentially invisible, at least with my unit.

10-11-2012, 02:05 PM	#465
Psykhe Connoisseur Posts: 77 Karma: 230000 Join Date: Sep 2010 Device: Kindle4, KindlePW	I got my PW today and seem to have been in luck. At least I am happy with it. I thought I might go a a bit more "scientific" with my review of its screen and its comparison to my 2 year old Kindle Keyboard. Photoshop can do more things than doing Kindle preview images for Amazon... I.e. measuring the black level of an area. Method used: have both Kindles next to each other equally far away from light source, take picture of both, load image in PS, convert to gray scale, use pipette tool with a decent area so you have a good average to take black level. Minimum/Maximum: Kindle Keyboard: 30 / 84 Kindle Paperweight: 28 / 84 So..pretty much the same without the light. The light is, however, always on. Even when it is off (aka setting 0). It is actually bright enough to read the Kindle in total darkness, although it wouldn't really be enjoyable reading. I do not usually read in the dark, though. This is my typical reading area and Kindle placement. With the light at minimum the difference is there still really small. But this changes considerably with a higher light level, though (12/24 in this case). Both Kindles are equally far away from the light, the PW has a minimum grayscale of 30 in the "white" areas while the KK has one of 50! The light of the PW also looks very even with some ambient light. Maximum grayscale is a bit trickier to measure due to the small letters, I should have used the maximum font size there, but, well, :effort: Anyway, on the PW maximum grayscale 75 is while on the KK it was 80. So there is some loss of black due to the light, but it is compensated by the increased white and then some. Here the PW in total darkness at the same light level (12/24). The light shadows at the bottom are visible and there seems to be a green? discoloration in the upper center. But is it really there or is it just some visual illusion? I think everyone of us has seen pictures where you see shadows where there are none. So lets do some Photoshop magic. Yes, there is definitely a light green discoloration without ambient light. It's not because the green light is faulty, btw (that one is pretty uniform), but because red and blue light have an "hole" there. But, honestly, I do not really care. I would have liked a perfect bleached white in darkness just as much as the next guy, but I would call it hardly a huge annoyance. And I mostly (as in 95% of the time) won't use it like this but with some ambient light. Which makes discolorations essentially invisible, at least with my unit. Last edited by Psykhe; 10-11-2012 at 02:55 PM.