Kobo is developing a 7.8 eReader

[PeterT]

Actually the intention is for the workers to refuse to work overtime.

[robko]

Originally Posted by PeterT

Actually the intention is for the workers to refuse to work overtime.

I heard that as one option, but I also heard rotating strikes etc as possibilities. The unions strike mandate ends Monday so they either have to do something or spend the money to go back to their members for a new strike mandate. Who knows where it will all land.

[Nick_1964]

Originally Posted by John F

And again, the video/review I saw showed some colors that looked nothing (relatively) like any of the other Kobo readers. As far as no individual sliders for blue, since we don't no the colors that the one slider is setting, it may be completely eliminating blue. Doing a quick search of (red + green), I get an "ugly khaki-brown", which may have been one of the colors I saw in the videos. I'm curious why you think that blue light is always there (on the Aura One), when (I think) in theory, it could be easily eliminated on the Aura One?

There where some Dutch tests but it have no use putting them here as they are made in newspapers (yes.. real paper) say it "reduces" blue light, not eliminating.
As they are printed articles..they can't be translated.
That light is not visible or noticeable, doesn't mean it isn't there. (lucky we don't see the infra red beams of all the remote controls or the layers on the Glo HD)
Why I think it is there, well my boss was the first one who bought me some pair of filtered lenses for my reading glasses because I work a lot on the computer.
The only way to filter out all the blue light is with a real filter (like in my case something you place for your glasses) for sure, using the slider will reduce it but in the most lowest form it is still there, and having said that, but that is personal, I really dislike the comfort light in the most reducing form.. it seems ugly to me.
So yes you can dim it, change it,and there will be much more less blue light, but it is still there,changing colors is not the same as filtering that is what I try to say.

[John F]

Originally Posted by Nick_1964

There where some Dutch tests but it have no use putting them here as they are made in newspapers (yes.. real paper) say it "reduces" blue light, not eliminating.
As they are printed articles..they can't be translated.
That light is not visible or noticeable, doesn't mean it isn't there. (lucky we don't see the infra red beams of all the remote controls or the layers on the Glo HD)
Why I think it is there, well my boss was the first one who bought me some pair of filtered lenses for my reading glasses because I work a lot on the computer.
The only way to filter out all the blue light is with a real filter (like in my case something you place for your glasses) for sure, using the slider will reduce it but in the most lowest form it is still there, and having said that, but that is personal, I really dislike the comfort light in the most reducing form.. it seems ugly to me.
So yes you can dim it, change it,and there will be much more less blue light, but it is still there,changing colors is not the same as filtering that is what I try to say.

It isn't just "changing colors though, it is (potentially) stopping the emission of blue light altogether. If only one LED is generating blue light, and it is turned off, how can blue light be transmitted?

"... In the most lowest form it is still there ..."

To anyone, is this true? So if the red LED is at 100%, and the green LED is at 100%, and the blue is at 0%, the red and green LEDs will emit some amount of blue? And in theory maybe they do, but is it even detectable by the human eye, or at an amount that is harmful?

I'm just curious to the "science" behind this. And FWIW, I'm not an LED or color expert.

[Cinisajoy]

Originally Posted by John F

It isn't just "changing colors though, it is (potentially) stopping the emission of blue light altogether. If only one LED is generating blue light, and it is turned off, how can blue light be transmitted?

"... In the most lowest form it is still there ..."

To anyone, is this true? So if the red LED is at 100%, and the green LED is at 100%, and the blue is at 0%, the red and green LEDs will emit some amount of blue? And in theory maybe they do, but is it even detectable by the human eye, or at an amount that is harmful?

I'm just curious to the "science" behind this. And FWIW, I'm not an LED or color expert.

According to Wikipedia, red+green makes yellow. According to another source red+green makes brown.
Back in 2 minutes with an answer.
And in an experiment done in my kitchen, one drop red + one drop green in a white bowl makes a funky purple.

[filmo]

Additive color wheel using different colour lights and subtractive color wheel using different color filters or pigments mixed is different.
https://en.wikipedia.org/wiki/Color_theory

http://www.worqx.com/color/color_systems.htm

[tnforpaul45]

Still thinking about ordering one, just dont need one!

[booklover6]

Originally Posted by tnforpaul45

Still thinking about ordering one, just dont need one!

Same here....in any case, I will wait a few months before I decide.

[datanoise]

Originally Posted by Nick_1964

changing colors is not the same as filtering that is what I try to say.

You're right. But do they change color (less blue before bed time) or do they filter the blue light that could be damaging for sleep patterns? (Maybe they do both?)

If they filter the light, does anyone knows what filter they use / how do they do that?

[Alan_S]

Originally Posted by John F

To anyone, is this true? So if the red LED is at 100%, and the green LED is at 100%, and the blue is at 0%, the red and green LEDs will emit some amount of blue? And in theory maybe they do, but is it even detectable by the human eye, or at an amount that is harmful?

First of all, blue light per se isn't harmful. You won't go blind, your head wouldn't explode (well, it may explode one day, I can't tell at the moment ).

Second, it depends on actual LEDs used. How LED's color is achieved?

There could be some blue light in it, but also it doesn't have to be. We should have exact LED's manufacturer specifications, or at least someone should test LED's light spectrum. Without it, we can only guess.

[DNSB]

Originally Posted by John F

It isn't just "changing colors though, it is (potentially) stopping the emission of blue light altogether. If only one LED is generating blue light, and it is turned off, how can blue light be transmitted?

"... In the most lowest form it is still there ..."

To anyone, is this true? So if the red LED is at 100%, and the green LED is at 100%, and the blue is at 0%, the red and green LEDs will emit some amount of blue? And in theory maybe they do, but is it even detectable by the human eye, or at an amount that is harmful?

I'm just curious to the "science" behind this. And FWIW, I'm not an LED or color expert.

Most red/green/blue LEDs are not only monochromatic, they have an extremely narrow bandwidth (See the attached image). There are several ways of making a white LED, one is to use red, green and blue LEDs in the same package with multiple leads, another (and more common) is to take a blue or UV LED and add phosphors* (much the same as a fluorescent light). The mix of phosphors used is what causes white LEDs to have different colour temperatures -- again similar to fluorescent lights.

*One difference is that white LEDs often use a single yellow phosphor, the light from which mixes with the blue LED light to appear white which is currently the most efficient but has lousy colour rendering. Other white LEDs use a mix of green and red phosphors to give a more continuous spectrum and a higher colour rendering index.

I've attached an image showing the bandwidth of typical RGB LEDs.

[Nick_1964]

Originally Posted by John F

It isn't just "changing colors though, it is (potentially) stopping the emission of blue light altogether. If only one LED is generating blue light, and it is turned off, how can blue light be transmitted?

"... In the most lowest form it is still there ..."

To anyone, is this true? So if the red LED is at 100%, and the green LED is at 100%, and the blue is at 0%, the red and green LEDs will emit some amount of blue? And in theory maybe they do, but is it even detectable by the human eye, or at an amount that is harmful?

I'm just curious to the "science" behind this. And FWIW, I'm not an LED or color expert.

I put it between spoiler tags as it is, in my opinion,far beside the goal of this thead and also about a small point of my "list" why i would skip this reader and I don't want to bother other readers of this thread.

Spoiler:

All kinds of leds have "unwanted" lights, lets call it, radiation ?
I don't know the right words for it, but they have a spectrum depending on the light and the way it is used to "diffuse" the light over the screen to be equally lighted.
If that was not been done, the screen would be lighted very bright in the lowest part of the screen, and the more higher it will be fainted..not so bright.
There is a special layer in the screen that devide the light so it is bright on every sight.
(My first Glo had holes in that layer so when you put the light to bright they look like there are stuck pixels on the screen,there was a complete batch out there with this mistake)
I don't want to start a discussion about what you see, or don't see and what I see or don't see,and what color I think the old Glo has or not because there are all different kind of leds..batch A give another kind of light then batch B and there is a lot of room for interpretation.
The reactions above show much better then I can tell (english is not my native language and I have only one years lessons in the english language)
There are cheap leds, and more precision leds and depending on the led quality you can be more precisely about the colors and the "not wanted" emission.

What about the light.. Harmfull ?? Never said that.
Some studies say that the blue inside the white light (used to get white) is stimulating the brains like it is daylight, and resets the biological clock so you get awake.
But what a lot of people forget is that very much lights around us are causing the same.
Your LED tv.. your computerscreen and the light i use beside my bed is also a led light and that emits light at 5 watts... so I can filter all the blue light of my Glo HD, but the "bedlight" and all surrounding lights does exactly the same so it has almost no value to remove it from my Glo if beside the bed or the room you are, all led lightings are emitting the same white (blue) light.
(but again some specialist say that you mustbe within a range of cm or dm (decimal metres) to have the effect on it. )
In theory the only way to remove the blue totally out of the led is by giving it a yellow filter over it (like some foil or like sunglasses) .
The cheap leds they use have a bandwith of surrounding light colors and for as far as I know you can change the color but the only thing you do is changing the intensivity of the other colors to change the idea of the blue light, but it is still there,depending on the used led.
If it affects you, is depending from person to person (if it is true about resetting the biological clock because even scientists don't all agree on that.)
They do use it for depressed people to give them "daylight therapy".

Now lets stop this discussion because this is way and way to far, it was only one very small part of my personal reasons not to buy it,and only because I think the word "filter" is being misused here, it was picked out and become a part of a total other discussion about leds itself.
My Normal Glo HD has the normal leds and the normal blue light in it and it didn't bother me at all.
If I don't want it, I use my special glasses with a build in filter layer that filters out the blue light.

[John F]

Originally Posted by Nick_1964

I put it between spoiler tags as it is, in my opinion,far beside the goal of this thead and also about a small point of my "list" why i would skip this reader and I don't want to bother other readers of this thread.

Spoiler:

All kinds of leds have "unwanted" lights, lets call it, radiation ?
I don't know the right words for it, but they have a spectrum depending on the light and the way it is used to "diffuse" the light over the screen to be equally lighted.
If that was not been done, the screen would be lighted very bright in the lowest part of the screen, and the more higher it will be fainted..not so bright.
There is a special layer in the screen that devide the light so it is bright on every sight.
(My first Glo had holes in that layer so when you put the light to bright they look like there are stuck pixels on the screen,there was a complete batch out there with this mistake)
I don't want to start a discussion about what you see, or don't see and what I see or don't see,and what color I think the old Glo has or not because there are all different kind of leds..batch A give another kind of light then batch B and there is a lot of room for interpretation.
The reactions above show much better then I can tell (english is not my native language and I have only one years lessons in the english language)
There are cheap leds, and more precision leds and depending on the led quality you can be more precisely about the colors and the "not wanted" emission.

What about the light.. Harmfull ?? Never said that.
Some studies say that the blue inside the white light (used to get white) is stimulating the brains like it is daylight, and resets the biological clock so you get awake.
But what a lot of people forget is that very much lights around us are causing the same.
Your LED tv.. your computerscreen and the light i use beside my bed is also a led light and that emits light at 5 watts... so I can filter all the blue light of my Glo HD, but the "bedlight" and all surrounding lights does exactly the same so it has almost no value to remove it from my Glo if beside the bed or the room you are, all led lightings are emitting the same white (blue) light.
(but again some specialist say that you mustbe within a range of cm or dm (decimal metres) to have the effect on it. )
In theory the only way to remove the blue totally out of the led is by giving it a yellow filter over it (like some foil or like sunglasses) .
The cheap leds they use have a bandwith of surrounding light colors and for as far as I know you can change the color but the only thing you do is changing the intensivity of the other colors to change the idea of the blue light, but it is still there,depending on the used led.
If it affects you, is depending from person to person (if it is true about resetting the biological clock because even scientists don't all agree on that.)
They do use it for depressed people to give them "daylight therapy".

Now lets stop this discussion because this is way and way to far, it was only one very small part of my personal reasons not to buy it,and only because I think the word "filter" is being misused here, it was picked out and become a part of a total other discussion about leds itself.
My Normal Glo HD has the normal leds and the normal blue light in it and it didn't bother me at all.
If I don't want it, I use my special glasses with a build in filter layer that filters out the blue light.

Since this is in regards to one of the major features of The One, I would consider it on topic, and since the OP hasn't objected, I'll continue.

So you have personal knowledge of the LEDs that Kobo is using? Looking at DNSBs graph, he says those are "typical", and I don't see much overlap of the different colors.

Again, FWIW, I don't really know. I was reading (I think it was Nate's) site, and it said there were 9 LEDs, 4 of which are RGB, so there may be more blue light than I was guessing; it all depends on how they are driving them for "night mode". Since night mode is for low light, I could see them only using the RGB LEDs, and mainly using the RG, so there could be little to no Blue.

Just a WAG.

[filmo]

Fluorescent lights output only UV light without thin phosphor coating on inside of tube. I used such light to help kill bacteria. Cool White fluorescent lights were commonly used inside and output excess magenta light that wasn't noticed by people but my motion picture camera with daylight balanced film recorded. Had to filter out the excess magenta with filter and have only same fluorescent light brand. Still saw some reflected magenta light off aluminium surface. This could also affect people working all day under these lights. Now many stores use daylight balance fluorescent lights and I use only 3200K fluorescent and LED lights in my house. Standard incandescent lamps were 2400 K.

https://en.wikipedia.org/wiki/Color_temperature

Phosphor used in Fluorescent and LED lights are much better now like today's electronics.

[DNSB]

Originally Posted by filmo

Fluorescent lights output only UV light without thin phosphor coating on inside of tube. I used such light to help kill bacteria.

Minor nit. A low pressure mercury vapour lamp without a phosphor layer emits UV but it also emits some visible light in the blue and green range. The main output is at 253.7nM (UVB range) with a second major spike at 184.9nm (UVC range) but there are some minor spikes in the visible range. I used to own an EPROM eraser with a little clear plastic plug that allowed you to see if it was on -- hopefully before your retinas were permanently erased. I will date myself and admit to owning a "black light" when I was much younger. From what I later read, that lamp used a phosphor to convert the UVB and UVC wavelengths to UVA and a special glass (Wood's glass?) envelope to filter out the remaining UVB/UVC.