Comment by carlosjobim | Hacker News Reader

Comment by carlosjobim | Hacker News Reader

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Maybe you live in a place where the sun doesn't shine that strongly? Because otherwise you could do a real life test and know that I'm right in 5 seconds.

I read books on my Kindle outdoors in the blazing sun, and so do most of the millions of people who have Kindles or similar devices. Contrast is excellent. In the same conditions an LCD phone is just a black mirror which you can hardly make out any kind of information form. An OLED is better, and you can see everything on the screen dimly if you strain your eyes. A TFT is even better, but none of them compares to eInk or paper.

So maybe you live in Britain or in Norway, or somewhere similar where it's cloudy all the time? You saying that paper is low contrast baffles me, actually. It seems like you are hung up on the contrast within the device, which is irrelevant for outdoor use, where the only thing which matters is the contrast as part of the real world environment.

Let me ask you, who is the faster runner: The fastest runner on your street or the slowest runner in the Olympics? Because you seem to be arguing for the former because of measuring within limits that do not confirm to the real world - where there is a sun.

I live in Texas. I think you are just confused about meaning of the word "contrast" because you keep using in a way that makes no sense for contrast but makes some sense for brightness. Contrast in this context is the ratio of luminosity between brightest and darkest areas of a display. For a non-emissive display such as e-ink or LCD in a bike computer the ambient light level makes zero difference: the white pigment in e-ink will reflect/diffuse ~15 times more light than the black pigment in the same. Light areas in an LCD screen will reflect 1000 times more light than dark areas. The absolute amount of light above quantum level makes zero difference, it's the same for a candle, Sun or a supernova star - the ratio i.e. contrast remains the same. An e-ink display can be brighter than a reflective LCD though due to higher albedo, this is likely what you are talking about.

Also, if you really try to do what you suggested - you should not use an LCD phone, phones do not have reflective LCD displays but use backlight instead so the contrast on those decreases with increase of the ambient as both light and dark areas reflect the same amount of ambient light and the only difference is the backlight's emissive portion, the higher is the ambient, the lower of the ratio i.e. contrast.

> Contrast in this context is the ratio of luminosity between brightest and darkest areas of a display.

That is the internal contrast of a screen or printed material. I agree, and that type of contrast is important if the screen emits its own light.

However, for outdoors use the only contrast that matters is relation to the real world, aka physical reality. And brightness of course becomes the main factor.

Also, thanks for pointing out you are talking exclusively about transflective/reflective LCD. It seemed to me for a while you were talking about any type of LCD. But even so, eInk and paper has better contrast in real life outdoors use, because we have to measure contrast in the human eye and not within the device.

The human eye adopts to the brightness in the environment and makes a contrast "scale" according to this. The nearer your screen's black color is to the black of the human eye's black in that situation, the better. And the nearer your screen's white color is to the human eye's white, the better.

If either your black or your white is too far from the human eye's calibration, then your screen is no good to use, no matter how good the internal contrast of it is.

There is no limit to how bright things can be or how dark things can be. So the internal contrast between a very deep pitch black and a very dark gray can be 1:10.000, but within a real world sunlit environment it all just looks like black. And this matters, because direct sunlight is 30.000 - 100.000 lux, while an office is maybe 500 lux.

>However, for outdoors use the only contrast that matters is relation to the real world, aka physical reality.

For you perhaps. I, for one, use screens to get information encoded in symbols and graphs, if all these symbols and graphs had no contrast with background I would not be able to distinguish them from the background. You seem to only care to compare the screen's brightness to the real world, perhaps losing your screen and then finding it in the real world, aka reality, is the main usage mode for you?

> But even so, eInk and paper has better contrast in real life outdoors use

You need to give a citation for this which would be pretty hard since we are already discussing a 12:1 device as shown by the spec sheet I've posted earlier. Or are you using "contrast" do describe brightness? In this case I agree - eInk's "black" is just a darker shade of gray so it reflects more light i.e. contributes to higher albedo. It's not great when you are trying to read from that screen but if you are just looking for the lost screen in the wilderness it won't hurt I guess.

You seem to be unfamiliar with bike computers but appear to be using your imagination instead of looking it up so I will state for the record - bike computers are affixed to bikes, a rider checks the computer during the ride and it's always in the same position, bike computers are not thrown into the wilderness to be searched for afterwards so locating one in the real world is rarely a problem facing a bike computer user. If one is detached in a crash, they always have radio and often speakers for more reliable mode of finding than the light reflected from the screen.

This thread was highly entertaining. Thank you two for arguing the topic and special thanks goes out to pandanman for his patience and composure. I guess I just found my next rabbit hole to investigate.

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