The ideal resolution is 100 ppi, said Apple in 2004 | Hacker News Reader

The ideal resolution is 100 ppi, said Apple in 2004

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30 pointssaint-loup23 comments

Actually, what Apple said was (as others have sagely pointed out), 100ppi was the best compromise given 2004 technology.

Can we cut out the silly Apple-bashing on here, please? There are plenty of intelligent criticisms to be made.

Actually, what Apple said was, "...a smaller monitor with a high resolution that causes eyestrain and headaches." Imagine all the headaches iPhone 4 users are going to have.

Here is a riddle for you:

Until today all the desktop monitors Apple sells hover around 100 ppi, whether they are Apple Cinema Displays or iMacs. The resolution of their MacBooks is a bit higher – the 13" and the 15" have 110 ppi, the 17" has 130 ppi – presumably because everyone sits a bit closer to Laptop screens.

Why did Apple pick that resolution and stick with it when it comes to Macs but why didn’t they have any qualms when increasing the iPhone’s resolution? And how does eyestrain figure into this whole discussion?

Solving this riddle will be easy if you don’t think so much about hardware but rather about software.

And here’s the answer: Gur evtug nafjre vf gung Nccyr jba’g trg gurve npg gbtrgure naq BF K vf fgvyy abg lrg erfbyhgvba vaqrcraqrag (hayvxr Jvaqbjf naq Yvahk). Pbafrdhragyl vagresnpr ryrzragf jvyy fuevax naq fuevax nf lbh vapernfr erfbyhgvba. Vg’f abg gur cvkry fvmr gung pnhfrf rlrfgenva, vg’f gur fvmr bs vagresnpr ryrzragf. Nccyr’f vBF vf erfbyhgvba vaqrcraqrag. Vagresnpr ryrzragf jvyy fgnl gur fnzr fvmr.

Semantic wankery: They did not say "in 2004", "at the time", or anything of the sort. They said around 100 dpi is "the ideal resolution" — no qualifiers except for "after years of experience".

I realize they meant this and I realize they didn't say it because Apple marketing tries very hard to not confuse users with not-strictly-necessary detail (and to make sufficiently general statements to be as generous to Apple products as possible without being outright misleading, but I digress). But no, they did not say it was the best compromise they could get at the time -- they said it was the absolute best.

edit: can the two downvoters state why they don't feel this correction of a statement regarding what "Apple said" adds to this discussion?

It's still true for Apple's desktops and (to lesser extent) laptops, which don't have resolution independence working yet:

Apple's latest 27" iMac has 108dpi. MacBook has 113dpi. Standard MBP has 110dpi.

I'm afraid the thrill of submitting and the limit of 80 characters made the title more sensationalist than it was in my mind. :]

This is not the same.

Let us consider the claims being made.

Now: 300ppi is the most you need to completely fool the eye (similar to how 24fps is typically considered all you need for fluid motion)

Then: Given 2004's technology, 100ppi is the best compromise between a tiny unreadable display with high ppi and a large pixelated display with low ppi

Also, computer monitors are typically farther away than a phone screen, so less resolution is needed to fool the eye.

If one uses 300ppi @ 11inches as the standard for a "retinal" display, 100ppi becomes retinal at 33 inches. I don't sit quite that far from my screen, though I suppose some people may.

And a couple other popular smartphones have been retinal at their typical usage distances for several months now.

Really you need somewhat higher resolution.

Apparently 20/20 vision is defined as being able to distinguish things 1 arc-minute apart. This comes to 114 dpi at the 30 inches away that I just measured my screen at. And yet when I pick a small-but-generally-readable font, I can see that for example the leftmost leg of an 'm' looks different than the other two.

So I would say you want sufficiently high resolution that pixelization artifacts aren't visible, which means that adding or subtracting one pixel from a one-arc-minute item leaves it still at one-arc-minute. Maybe 2px/arc-minute would do this well enough, maybe it would take 3. But 1px/arc-minute still permits visible artifacts.

How did you calculate 33 inches?

I need a diagram. I'll use the one on wikipedia's visual angle page.

At 11 inches, 1 inch has a visual angle of about 5.2 degrees. But the exact number doesn't much matter. You can set two instances of the visual angle equation equal (one for the unknown distance and one for the definition of retinal, an inch long at 11 inches distance), and simplify to give you what similar triangle ratios would too. A length, s=D/11, for the side of the similar triangle opposite the eye, which by the operating definition of "retinal" has 300pixels along it. So, we can use s as a scaling factor, 300ppi/(D/11)="ppi you need at distance D to be retinal". Solve for D instead if you wish.

That might not even be clear with the diagram, sorry.

Presumably he's using a constant ppi × distance value, though it's not clear that's the right method to use

What is this tiny, unreadable display you speak of? Oh, OS X doesn't support system-wide font size increasing... hmmm...

24fps is not "the most you need to completely fool the eye." There's a reason gamers want high fps; because humans can definitely perceive the difference.

24fps is what's needed for film, because it's fast enough for persistence of vision to carry one frame's image over to the next while the shutter is closed. And in film, motion usually gets smoothed by the non-zero exposure time. If video games could employ sophisticated motion blur, they could generally get by with 24fps as well.

24fps is not based on persistence of vision. Persistence of vision exists at 23fps or 22fps and lower for some people. 24fps is an historical artifact of the first few generations of motion picture technology. It is maintained because humanity has grown accustomed to 24fps in theaters for film material. With the advent of video (video tape) and prolific 30fps material (60i material), many people perceive film shot at 30fps to be video and vice versa.

Ultimately, it is an aesthetic.

24 fps is barely acceptable. Forget fast pans and any other fast camera movement. Increasing that number will be hard, though, because over decades we learned to associate 24 fps with cinematic quality and higher frame rates with cheapo camcorders.

Not really. Actually I think the GP was mistaken. The big reason gamers don't want 24FPS is because if it's 24FPS during normal play, it's gonna stutter. There will be times when it goes down to, say, 12 FPS, if not lower. And 12 FPS is simply not good enough for anything.

And of course, there's one thing about employing sophisticated motion blur-- you're not going to do it just to lower FPS. Real motion blur is quite expensive. There's really no point except for the visual coolness.

A lot of my film buff friends claim that films with higher than 24 fps look a lot better. There's a kind of format called Maxivision that can be projected 48:

http://en.wikipedia.org/wiki/Maxivision

Funny as a soundbite, but really apples to oranges.

yes, the ideal resolution was 100 ppi in 2004.

Nothing like a walk down the memory hole.

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