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Comment by throwanem | Hacker News Reader

E-ink's contrast ratio is quite poor, typically around 8:1 and with even marketing claims topping out around 12:1. For comparison, a baseline gallery-quality inkjet with good glossy photo paper can easily exceed 200:1, and professional repro methods do better still.

So, emulating newsprint is a good e-ink use case, since newsprint's contrast sucks too. But black and white photos, which depend critically on effective use of contrast for a lot of their effect, will not look good on an e-ink display, any more than they would on a Game Boy.

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> For comparison, a baseline gallery-quality inkjet with good glossy photo paper can easily exceed 200:1, and professional repro methods do better still.

That's only for glossy though, right? That comes with glare, which is annoying for reading.

Matte is "only" around 50:1, which still beats e-ink by a lot. Newsprint struggles to approach even that because the inks are formulated to be inexpensive, thus not heavily saturated, so the "black" is really a dark gray, and the paper is cheap pulp that probably couldn't be bleached really white without disintegrating anyway.

For the quoted 1500$ for the display I could buy a printer and print the page for quite some time...

A large-format printer, yet. A Pixma Pro 1000 that can do excellent 17x22-inch prints - and color! - only runs about a grand, so you'd even have a bit left over for some good Hahnemuhle photo paper.

While the format is an important point, I don’t understand why one would print a newspaper front page on good paper?

Beats me, but that's not really my point anyway. Displaying photographs was cited as a good use case for an e-ink display, and as a photographer who puts considerable effort into producing high-quality display prints of their work, I felt it worth explaining why that's a terrible use case for e-ink.

(Anyway, why do people frame newspaper front pages? Given the total lack of archival quality in newsprint, I could see scanning and printing to frame in a way that'd hold up better over time.)

I don't think those use-cases are in collision with one another. I'd be happy to take an e-ink display for photographs.

But also buy high-quality prints as well. Even though both will end up on the wall they are totally different use-cases.

Are they? I don't see how. Where's the use in displaying a photograph, at whatever size, as a muddy, contrastless mess?

The advantage of e-ink is that it blends perfectly with the ambient lighting, without eyestrain or backlight bleed. Low contrast is kind of the point, combined with the ability to change the display remotely/automatically.

What's here under discussion is contrast ratio - not contrast between the image and its surroundings, but contrast between the lightest and darkest tones that can be represented within the image itself. Another term would be "dynamic range", if that helps; "contrast ratio" is how the concept is typically expressed in the context of raster displays, so that's what I've gone with here.

Under either name, it's a major figure of merit for quality of image reproduction, and my point is that e-ink, being worst at it of any raster display technology of which I'm aware, is thus a very poor choice for displaying images if quality of reproduction is a criterion.

I know, and quality of photographic reproduction is not a criterion I would need from an eink display. My goal is subtlety. Honestly in a parallel universe I have probably built the same exact prototypes from the blog. My (defunct) startup was called Nitrogen Logic because technology should be as critical but invisible as the nitrogen in the air.

I am totally fine with an 8:1 contrast ratio if it gives me perfect integration into the ambient light :)

Photography would be displayed elsewhere, in a place that is meant to draw attention. I want eink because it shouldn't grab attention at all.

Family vacation? The LCD picture frames are popular and can be described just like that. Even the kindle grayscale images could be decent as decoration. (I'm guessing e-ink would look best in grayscale, but I haven't seen one in color)

Maybe not the living-room centerpiece, but still.

Even there, much better options exist. For the same money you can get a 55" Samsung Frame with color, excellent contrast, and that also doubles as a quite good TV - it can be the living-room centerpiece.

Much better for what? I'd never use that - absolutely hideous for the use-cases I'd use an e-ink for.

I'd use the one in the article in a heartbeat, much more elegant and no backlight. No it won't display a photograph as good as the Samsung but it will not be cheesy or look out of place (or consume tons of energy) - which the Samsung will if it is positioned anywhere else but in front of and in eye-level of a sofa.

The only thing it is good for is as a TV, which I guess is great if you want a TV.

I'd rather take a chance on the Frame's automatic backlight adjustment to match the ambient light level maybe working, than on e-ink which guarantees poor reproduction.

It's just super odd to me to think about wanting to go to all the trouble of displaying an image at that size and scale, and also being willing to accept it looking as lousy as e-ink's awful contrast will necessarily make it. Sure, it's a lot easier to change the displayed image than it is with a paper print, but what's the benefit of that when they're all going to look equally bad?

Granted I'm a photographer and I want my own work to look good, but it's not as if I had to develop that interest to want whatever I did put on my walls to look good...

You could print glossy magazine covers.

Perhaps you could even pay a company to print the entire paper for you and have it delivered to your door every morning.

But you can read it outside.

Presumably taking it off the wall, first?

I don't claim that e-ink has no use case, only that it's bad at displaying photographs. If you mean to argue otherwise, please do so with respect to statements I've made, rather than to ones I have not.

I was addressing the contrast ratio, which people seem to sort of measure inadequately in sunlight.

There are two comparisons between LCD displays that should properly be referencing S/N ratio instead of contrast.

With a glossy display, whatever is behind you STRONGLY affects your S/N ratio, especially in black.

In sunlight even a very bright LCD is washed out almost to unreadability (though I am surprised how well recent phones still manage to still function)

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