Existing and upcoming iOS device screens and the metric system

▼ Have you ever noticed how the iPad has strange screen sizes? 9.7 and 7.9 inches. The same for the rumored new iPhone sizes: 4.7 and 5.5 inches. Turns out some of these screen sizes are nice, round numbers... in the metric system.

First a short metric system refresher for my American readers. It all begins with the meter (m). Long distances are measured in kilometers (1 km = 1000 m). Short distances are measured in centimeters (100 cm = 1 m) or millimeters (1000 mm = 1 m, 10 mm = 1 cm). A liter (l) is a volume the size of 10 by 10 by 10 cm, and a liter worth of water weighs 1000 grams, or a kilogram (kg, also just "kilo" in common parlance). The main thing you have to remember is that an inch is 2.54 cm or 25.4 mm.

Interestingly, on its English language web pages, Apple dutifully lists all the outward dimensions of the iPad Air both in inches/pounds and (tens of!) millimeters and grams. In other languages, only millimeters/grams are mentioned. Except for the screen. That's 9.7 inches, period. Even in French. The same thing for the iPad mini with its 7.9" screen.

Let's do some calculations:

	Screen diagonal
iPhone 4	3.5" x 2.54 =	8.89 cm
iPhone 5	4" x 2.54 =	10.16 cm
iPad Air	9.7" x 2.54 =	24.64 cm
iPad mini	7.9" x 2.54 =	20.07 cm
iPhone 6 small	4.7" x 2.54 =	11.94 cm
iPhone 6 big	5.5" x 2.54 =	13.97 cm

Not so round. However, if we also take into consideration the pixel resolution and pixels per inch numbers that Apple publishes, things look slightly different:

	Resolution	PPI	Screen in	D in	px/cm	Screen cm	D cm
iPhone 4	960x640	326	2.95x1.96	3.54	128	7.5x5	9
iPhone 5	1136x640	326	3.48x1.96	4	128	8.88x5	10.19
iPad Air	2048x1536	264	7.76x5.82	9.69	104	19.69x14.77	24.62
iPad mini	2048x1536	326	6.28x4.71	7.85	128	16 x 12	20

(Screen in / Screen cm: screen height x width in inches / cm. D = screen diagonal.)

Conclusion: the iPhone and iPad mini use a pixel density that makes for nice round numbers for the display size in the metric system, with the original iPad being the odd man out. So what about the rumored 4.7" and 5.5" sizes for the iPhone 6? That would be 11.938 and 13.97 cm, respectively. Which probably means it's going to be 12 and 14 cm, or 4.72" and 5.51".

John Gruber's conjecture lands at 750 x 1334 for the small one. If that one has a 12 cm screen at 326 PPI = 128 pixels/cm, that comes out to:

	Resolution	PPI	Screen in	D in	px/cm	Screen cm	D cm
iPhone 6 small	1336 x 752 *	326	4.11x2.31	4.72	128	10.46x5.88	12

Note that this is different from the 1366 x 768 result I got last week. I then used 10 cm for the iPhone 5 screen size, and assumed 4" → 4.7" actually meant 10 → 12 cm, a 20% increase. But the iPhone 5 screen is actually 10.2 cm, so a 20% increase in size would be 10.2 → 12.24 cm, which is 4.82" and not in the 4.65" - 4.74" range that would be rounded to 4.7". I think if Apple had wanted to stick with 326 PPI / 128 pixels/cm, they'd have gone for the extra 2.4 mm diagonal screen size, which only adds only 1.2 mm to the width of the screen but makes the pixel numbers work out much better.

I still think 1280 x 720 is the most likely resolution for a 12 cm iPhone 6, because it's a nice round number and allows for slightly bigger text for unupdated applications while still providing a reasonable number of extra pixels. Assuming the 14 cm version would use the same pixel density, that comes out to:

	Resolution	PPI	Screen in	D in	px/cm	Screen cm	D cm
iPhone 6 small	1280x720	311	4.11x2.31	4.72	122	10.46x5.88	12
iPhone 6 big	1488x840 *	311	4.8x2.7	5.51	122	12.2x6.86	14

But we'll know soon enough.

* Rounded a bit to a number divisible by a power of two.

Permalink - posted 2014-08-26

Was the iPad a fad?

▼ Many people's first take on the iPad was that "it's just a big iPod touch". And so it is, really. But sentiments changed quickly as sales numbers skyrocketed: the king (the computer) is dead, long live the new king (the iPad). But then iPad sales numbers went down for two consecutive quarters. While Mac sales were up.

There are of course many possible explanations: iPads aren't upgraded biennially¹ like phones, but rather every three years or longer. Apple's prices are too high. Competition from cheap Android tablets.

Software on the iPad doesn't seem to do very well, either, which has its own issues, but I think the real reason for lack of both hard- and software sales is that the iPad simply isn't as useful to as many people as industry watchers thought.

Although I'm pretty deep inside the Apple eco system, having bought six Apple laptops and three iPhones (one of each every two years), I never got an iPad. The laptop can do everything, the phone is with me 24 hours a day. Do I really want to spend money on a third device that occupies middle ground? My answer: no. Especially not as long as Apple limits what kind of software gets to run on the iPad. On a phone that makes some sense, as it has a tiny battery and the phone function needs to work reliably. But not on the iPad, which is for all intents and purposes a general purpose computer that's rarely far away from a power outlet for long.

The way I see it, the iPad has three main use cases for consumers:

1. Early adopters. Why sit on the couch with a big laptop or a small phone when you can have a third device that's perfect for that particular use case?
2. Young kids. The touch interface and the size of the device is perfect for them.
3. Reluctant computer users. No file system, simplified OS and user interface, but they still get to browse the web, send the occasional email and the like.

The trouble with the first group is that there are only so many people who are willing to spend the money for something that is just a little bit better for some uses than something they already have. The same thing for kids: kids tend to break stuff, and iPads aren't cheap. So unless/until the price comes down, or maybe until Apple introduces a more rugged model, the main market for iPads has to be people who prefer the simplicity of an iPad over the complexity of a computer.

I just don't think this group is as big as many people seem to think. My mother was around 50 when she got her first computer. I was surprised at how well she managed to use it. That was more than a decade ago, when things like networking and managing photos and music were much harder than they are today. Most people under 60 manage just fine with "real" computers, and aren't going to give up useful features for the simplicity of an iPad.

And if iPads can't displace real computers, they're going to remain a third device, which only does a few things better than a laptop or a smartphone, but adding the hassle of another device to manage and charge, as well as the complexity of syncing data between devices. Sure, iCloud is supposed to take care of that, but only if you're 100% in the Apple ecosystem and don't mind having your data on remote servers. And that's when everything works the way it's supposed to.

I believe the early sales numbers of the iPad were largely fad-fueled. The fad seems to be over now. I'm sure tablet-like devices are here to stay, but so are regular computes. The next clash will be when ballooning smartphone screen sizes and shrinking tablet sizes meet in the middle. However, don't be deceived by "5.5 inch" iPhones vs "7 inch" (actually 7.9") iPads. The new extra big iPhone would have a 12.4 x 7 cm screen, while the iPad mini has a 16 x 12 cm screen. So the iPad mini still has more than twice the screen area as a 5.5" iPhone.

¹ Originally I wrote "semi-anually", but it was brought to my attention that the word is spelled "semiannually" (I know I shouldn't trust the spell checker!) and it actually means twice a year. The correct term for every other year is biennially, not to be confused with biannually, which again means twice a year.

Permalink - posted 2014-08-25

Apple announces iPhone 5 battery replacement program

▼ That was fast. No sooner had I complained about my iPhone 5 battery:

When I got my iPhone 5, I did a bunch of battery tests, and at that point, the battery life was pretty much identical to that of my iPhone 4, which was two years old by then. However, pretty soon I started having issues where the phone would shut down if I tried to do too much at the same time if the battery was below 50%, especially in cold weather. (Taking a photo would typically do it, as that fires up the GPS which in turn causes cellular data traffic.) It took me a while to figure out that five minutes later, I could turn the phone back on. These days, I have to be very careful with the way I use my iPhone in order to make it last through the day on a single charge.

...or Apple announces the iPhone 5 Battery Replacement Program!

The program only applies to certain iPhone 5s (as in: multiple of iPhone 5) sold until January 2013. You fill in your serial number and then you're told whether your iPhone qualifies. And mine does, which is great news. So now I have to bring it in to the brand new Apple Store here in The Hague to have the battery replaced. Actually, when I was there for the opening two weeks ago, I had them check my battery, but it was still freshly charged and showed a capacity of just under 80%. They would have replaced it under warranty, but as the phone is almost two years old and I didn't get Apple Care, I'd have to pay about € 110, which is too steep if I end up buying a new iPhone later this year.

I wonder about the replacement process: will they replace the battery in the back? Ship it somewhere else? If so, how long will that take? Or will they simply replace the phone with a new one? If so, really new, or refurbished, with possibly some wear on the outside?

The program goes into effect on Friday outside the US and China, so I think I'll bring the phone in a week from Monday and then I'll find out. I'm doing a "only play audio until the battery dies" test today to compare pre and post replacement battery life.

Permalink - posted 2014-08-23

Photographing fireworks remains tricky business

▼ Tonight is the third night of the Scheveningen International Fireworks Festival! Hopefully the rain will be done by then. Photographing fireworks remains tricky business, though.

Last week, I used my trusty Nikon D7100 with the 18-55 mm kit lens. The zoom range is fairly suitable here, and it has image stabilization, so I was able to get reasonably sharp photos at 1/8th of a second hand-held. However, they're not quite as sharp as I hoped, so maybe if the weather is good tonight I'm going to take a tripod, so I can use even longer shutter times to get more of the streaming effect.

It could be that a lot of the movement in the fireworks in caused by the wind blowing the fireworks away, though. A tripod isn't going to help against that.

I set up the camera for "back button focus", so I had more control over the autofocus. Back button focus means programming the AE-L/AF-L button for "AF-ON". With this setting, pressing the shutter doesn't make autofocus happen, you need to press the AE-L/AF-L button for that. This way, there's no autofocus delay when shooting, which is useful with fireworks, because the autofocus system can't always get a good focus lock on it. But with cheap zoom lenses it's important to refocus after zooming, because the focus drifts when zooming. A quick press of the AE-L/AF-L button while pointing the camera at a distant light takes care of that.

I set the aperture and shutter speed manually, but used auto ISO so the camera would adjust the ISO to match the brightness of the fireworks. I experimented with -0.7 to -2 exposure compensation, and -1.3 seemed to work the best.

Permalink - posted 2014-08-22

Thinking about the iPhone 6

▼ It looks like the introduction of the iPhone 6 is only a few weeks away. And if the rumors are to be believed, it's going to be bigger than the iPhone 5/5S/5C. People talk about 4.7 inches vs 4 inches for the iPhone 5 family, which I'll take as 12 cm vs 10 cm—a 20% increase¹.

That 10 cm for the iPhone 5 is the screen diagonal, which means that the screen is 5 by 8.8 cm. The size of the iPhone 5C is 5.7 by 12.4 cm, so it's 0.7 cm wider and 3.6 cm taller than the screen. If the iPhone 6 also has a screen with a 16-by-9 aspect ratio, that means the screen will be 6 by 10.6 cm. So if nothing else changes, the phone would be 6.7 cm wide and 14.2 cm tall. However, it makes sense that Apple would be able to trim the bezel, especially the "forehead" above the screen—it will be harder to shrink the "chin" now that it houses a fingerprint scanner. So the iPhone 6 is going to be big, but not huge. I currently have a case for my iPhone 5 that's 13.2 by 7.1 cm, and that's entirely workable.

I'm certainly interested in having a bigger phone, as my current iPhone 5 is still very cramped when it comes to reading text and watching video. Some people argue that a big phone is problematic because you can't reach the corners of the screen onehanded. I find that a nonsensical argument. There's no law that says touch targets need to be in the far corners of the screen. In that regard, it's strange that buttons (well, to the degree that iOS still has buttons) tend to be at the top of the screen these days, while earlier they used to be at the bottom, within an easy thumb's reach. However, the now-common left-to-right swipe to get back to the previous screen helps a lot.

But the question is: if the new iPhone has a larger screen, how will the extra space be used? To fit the same amount of text, but in larger type, so it's easier to read, or to fit more text at the same size? There's something to be said for both, so I hope that Apple will make this a user choice. (They already sort of do that by letting you select a text size preference in iOS 7.) A related question is what the pixel dimensions of the iPhone 6 will be. There are basically four choices:

1. 1136 x 640: the same number of pixels as the iPhone 5/5S/5C, 106 pixels/cm (271 pixels/inch)
2. 1364 x 768: the same pixel size as the iPhone 5/5S/5C at 128 pixels/cm (326 pixels/inch)
3. 1280 x 720 HDTV resolution at 120 pixels/cm (305 pixels/inch)
4. 1920 x 1080 HDTV resolution at 180 pixels/cm (457 pixels/inch)

I'm thinking (and hoping) that it's not 1136 x 640. Apple has refused to play the "let's go to insanely high resolutions" game that has been going on on the Android side, but dropping below 300 PPI while some Android phones are pushing 500 would probably be too much of an alleingang, in my opinion. I also doubt that Jony Ive and his team would allow ugly pixels to be visible. The advantage would be that no changes to iOS applications would be required.

1364 x 768 would be an obvious choice, as there's no hit in pixel resolution. Also, 768 is a familiar number from the iPad screen. However, I don't think there's much synergy there as text size and touch targets intended for the iPad would be way too small on an iPhone—the screen of the iPad mini is twice as wide (12 cm) as that of the assumed iPhone 6 (6 cm). Also, how would existing iPhone apps run? Scaling 1136 x 640 to 1364 x 768 would probably not look great, and not scaling means that there's a 0.5 cm border on the sides and 0.9 cm border on the top and bottom of the screen (in portrait orientation). Far from ideal.

I think 1280 x 720 makes the most sense. I'm not sure to what degree Apple values using round numbers, but 1280 x 720 is a widely used HDTV resolution, which can't hurt. At these pixel dimensions, the screen resolution would be still be a hair over 305 PPI, which is the magic "Retina®" resolution. (As far as there is such a thing.) Unupdated iPhone applications could be displayed with borders on all sides, which would be 0.3 cm left and right and 0.6 cm on the top and bottom (portrait mode). That seems fairly workable—the iPhone 5 had almost 0.7 cm borders at the top and bottom when running unupdated apps.

Finally, there's the possibility that Apple decides if a 1280 x 720 HDTV resolution is good, the higher 1920 x 1080 HDTV resolution would be great. I highly doubt they would do this, as such a high resolution provides diminishing returns, but does require a good deal more processing to push more than twice the number of pixels around. Also, the new pixel resolution would be 1.6875 times bigger than the old one, requiring non-integer scaling of applications. Or with small black borders, the scaling factor could be 1.5 times for "retina" apps and 3 x for low resolution applications. That just doesn't seem The Apple Way. Then again, last year Apple decided it was time for 64-bit computing in the mobile space, and nobody saw that coming.

Hopefully, the iPhone 6 comes with 2 GB RAM. The current 1 GB RAM isn't as tight as 128 (!), 256 and 512 MB in various earlier iPhones, but 64-bit code as well as the duplication required to run 32-bit and 64-bit code side by side eat up a good amount of extra RAM and it's good to have some reserve to power future iOSes.

It's high time that 16 GB as the default storage option goes away. On my iPhone 4, 32 GB was pretty spacious, although even four years ago, paying € 100 extra for the upgrade from 16 GB was expensive. But iOS has bloated a lot, and with a few big applications and 16 GB music, I barely have room for a video or two. So I really need a 64 GB iPhone, and I'm not going to pay € 200 extra for that. You can buy a 500 GB SSD for that kind of money these days.

Last but not least, I hope Apple can resist making the iPhone 6 ultra-thin, and leaves room for a decent battery instead. When I got my iPhone 5, I did a bunch of battery tests, and at that point, the battery life was pretty much identical to that of my iPhone 4, which was two years old by then. However, pretty soon I started having issues where the phone would shut down if I tried to do too much at the same time if the battery was below 50%, especially in cold weather. (Taking a photo would typically do it, as that fires up the GPS which in turn causes cellular data traffic.) It took me a while to figure out that five minutes later, I could turn the phone back on. These days, I have to be very careful with the way I use my iPhone in order to make it last through the day on a single charge.

I've been buying new iPhones every two years since 2008, so I could very well buy the iPhone 6 this year. (And it certainly helps that a new Apple Store has opened pretty much within walking distance from my house!) On the other hand, the even years bring unproven redesigns. Two years ago, there was the lightning cable annoyance, and it took Apple a year to get around to releasing new docks. So I could also see myself skipping a year, replace my iPhone 5's battery instead, and see what the iPhone 6S or 6C brings next year.

¹ Update: actually it's 10.2 cm, so going from the iPhone 5 family to a 12 cm iPhone 6 constitutes a 18% increase in size, not 20%. Also see this post.

Permalink - posted 2014-08-21